The most common adverse reaction to insulin is
Rationale:
Hypoglycaemia. This reaction occurs when insulin lowers blood glucose levels excessively, leading to symptoms like shakiness and confusion. It is the most frequently observed adverse effect among insulin users, making it paramount for management.
B: Lipodystrophy. This condition involves abnormal fat distribution due to repeated insulin injections, but it is less common compared to hypoglycaemia and primarily affects localized areas over time.
C: Urticaria. This allergic reaction manifests as hives or rashes, which can occur but are significantly rarer than hypoglycaemia and not a routine consequence of insulin administration.
D: Angioedema. This severe swelling can occur in response to allergens but is quite rare in insulin users and does not represent the most common adverse effect associated with insulin therapy.
The second generation sulfonylurea hypoglycaemics differ from the first generation one in that they
Rationale:
Second generation sulfonylurea hypoglycaemics are more potent than first generation ones. This increased potency allows for lower doses to achieve the same glycemic control, enhancing their effectiveness in managing diabetes.
B: Are longer acting. While some second generation drugs have differing durations, potency primarily distinguishes them, not the length of action, which varies among individual medications.
C: Do not lower blood sugar in nondiabetic subject. Both generations can influence blood sugar levels; however, the focus is on their effectiveness in diabetic patients, not nondiabetics.
D: Are less prone to cause hypoglycaemic reaction. Both generations carry a risk for hypoglycemia, but the second generation's increased potency can sometimes lead to more significant risks, not less.
Patients taking chlorpropamide should avoid products containing
Rationale:
Patients taking chlorpropamide should avoid products containing ethanol. Ethanol can cause severe hypoglycemia when combined with chlorpropamide, leading to dangerous drops in blood sugar levels and potential health complications for patients managing diabetes.
A: Acetaminophen Acetaminophen does not have a direct contraindication with chlorpropamide, making it safe for use in managing pain or fever for these patients.
C: Vitamin A There are no significant interactions between vitamin A and chlorpropamide, allowing patients to consume vitamin A without concern regarding their blood sugar levels.
D: Penicillins Penicillins do not interact adversely with chlorpropamide, so patients can safely use these antibiotics when necessary for bacterial infections without risking their diabetes management.
Which of the following features disfavors use of oral hypoglycaemics in diabetes mellitus?
Rationale:
Insulin requirement more than 40 U/day. This high insulin requirement indicates a more severe form of diabetes where oral hypoglycemics may not sufficiently manage blood glucose levels, necessitating insulin therapy for effective control.
A: Age at onset of disease over 40 years. This factor alone does not determine the appropriateness of oral hypoglycemics, as many patients in this age group respond well to them.
C: Fasting blood sugar level between 100-200 mg/dl. This range suggests that blood glucose levels may still be manageable with oral agents, thus not contraindicating their use.
D: Associated obesity. While obesity can complicate diabetes management, it does not inherently disfavor oral hypoglycemics, as these medications can still be effective in overweight patients.
Insulin resistance can be overcome by the use of
Rationale:
Monocomponent insulin preparations can effectively overcome insulin resistance. These formulations consist of a single type of insulin, allowing for better management of blood glucose levels and more predictable effects on insulin sensitivity.
A: Corticosteroids can exacerbate insulin resistance, as they promote gluconeogenesis and can lead to elevated blood sugar levels, counteracting any potential benefits to insulin sensitivity.
B: Tolbutamide stimulates insulin secretion from the pancreas but does not address the underlying insulin resistance, which is essential for effective glucose management in patients.
C: Protamine is a protein that is primarily used to prolong the action of insulin; it does not directly improve insulin sensitivity or overcome resistance.
Metformin is preferred over phenformin because
Rationale:
Metformin is less liable to cause lactic acidosis.
This is significant because lactic acidosis is a serious side effect associated with certain diabetes medications. Metformin's favorable safety profile makes it a safer long-term option for managing blood sugar levels, particularly in patients who may be at risk for this condition, unlike phenformin which has a higher incidence of lactic acidosis.
A: It is more potent. While potency is important, metformin’s effectiveness is not solely based on strength but its overall safety and reduced risk of adverse effects, like lactic acidosis.
C: It does not interfere with vitamin B12 absorption. Although this is a valid point, the primary concern when choosing these medications revolves around their safety profiles, particularly regarding serious side effects, rather than vitamin absorption issues.
D: It is not contraindicated in patients with kidney disease. Although metformin is often used cautiously in these patients, the key difference from phenformin lies in its lower risk of lactic acidosis rather than its contraindications.
The insulin receptor is a
Rationale:
The insulin receptor is a tyrosine protein kinase receptor. This classification is accurate because the insulin receptor functions by autophosphorylation on tyrosine residues, initiating a signaling cascade essential for glucose metabolism and homeostasis.
A: Ion channel regulating receptor This option misrepresents the insulin receptor’s function, as it does not serve as an ion channel but rather activates intracellular signaling pathways through phosphorylation.
C: G-protein coupled receptor Unlike G-protein coupled receptors, the insulin receptor directly phosphorylates substrates and does not rely on G-proteins to transmit signals, making this classification incorrect.
D: None of these This choice disregards the established role of the insulin receptor as a tyrosine protein kinase receptor, which is a recognized and specific classification for its function.
Which of the following is a neuroglucopenic symptom of hypoglycaemia?
Rationale:
Abnormal behavior is a neuroglucopenic symptom of hypoglycemia. This symptom arises due to insufficient glucose supply to the brain, leading to cognitive dysfunction and alterations in normal behavioral patterns, reflecting the brain's need for glucose.
A: Sweating represents a sympathetic response to low blood sugar, not a direct neuroglucopenic effect on brain function.
B: Palpitation signifies an adrenergic response, indicating physiological stress rather than direct neuroglycopenic impact on cognitive processes.
C: Tremor results from sympathetic nervous system activation, which occurs in reaction to hypoglycemia rather than as a consequence of impaired brain glucose availability.
Sulfonylureas do not lower blood sugar level in
Rationale:
Sulfonylureas do not lower blood sugar levels in insulin-dependent diabetics. This is because these medications stimulate insulin secretion from the pancreas, which is ineffective when the body relies on external insulin for glucose control.
A: Nondiabetics Sulfonylureas have no impact on blood sugar levels in nondiabetics, as they do not have underlying insulin resistance or deficiency that these medications target.
B: Noninsulin dependent diabetics Sulfonylureas can effectively lower blood sugar levels in noninsulin-dependent diabetics by increasing insulin secretion, as they still produce some insulin from their pancreas.
D: None of these The phrase "none of these" implies all options are valid, which is misleading since insulin-dependent diabetics are indeed unaffected by sulfonylureas regarding blood sugar control.
The duration of action of insulin-zinc suspension (lente insulin) is
Rationale:
The duration of action of insulin-zinc suspension (lente insulin) is 20-24 hours. This duration reflects the formulation's characteristics, allowing for a prolonged effect in managing blood glucose levels, making it suitable for patients requiring extended insulin coverage throughout the day.
A: 2-4 hours This option suggests a very short duration, which does not align with the pharmacokinetics of lente insulin, as it provides significantly longer-lasting effects.
B: 8-10 hours This timeframe underestimates lente insulin's effectiveness, as it typically remains active for much longer, providing more sustained glycemic control than this option implies.
D: 30-36 hours This duration exceeds the expected action of lente insulin, as it does not maintain effectiveness beyond the recognized range, potentially leading to mismanagement of insulin therapy.
A diabetic on oral hypoglycaemic drug chlorpropamide, suffered from enteric fever and was prescribed chloramphenicol. He developed severe hypoglycaemia. This is because
Rationale:
Chloramphenicol inhibits the metabolism of chlorpropamide. This interaction leads to elevated levels of chlorpropamide in the body, intensifying its hypoglycaemic effects and resulting in severe hypoglycaemia in the patient.
A: Chloramphenicol itself has mild hypoglycaemic effect. While chloramphenicol may have some impact on blood sugar levels, its primary role in this scenario is related to its effect on chlorpropamide metabolism.
B: Chloramphenicol increases the absorption of chlorpropamide. Chloramphenicol does not enhance the absorption of chlorpropamide; instead, it affects its breakdown, leading to increased concentrations and hypoglycaemia.
C: Chloramphenicol causes release of insulin. Chloramphenicol does not stimulate insulin release; its interaction with chlorpropamide is centered around inhibiting its metabolism, which results in heightened hypoglycaemic risk.
Sulfonylurea hypoglycaemics act by
Rationale:
Sulfonylurea hypoglycaemics act by both increasing insulin secretion from the pancreas and reversing down-regulation of insulin receptors. This dual action enhances insulin availability and sensitivity, effectively lowering blood glucose levels in individuals with diabetes.
A: Reducing intestinal absorption of glucose focuses solely on glucose uptake mechanisms, which do not encompass the broader functionalities of sulfonylureas in insulin modulation.
B: Increasing insulin secretion from pancreas describes one aspect of sulfonylureas, but fails to acknowledge their role in counteracting insulin receptor down-regulation, which is also crucial.
C: Reversing down-regulation of insulin receptors highlights an important effect but overlooks the essential function of enhancing insulin secretion, making it incomplete in describing sulfonylureas' overall mechanism.
The standard recommended dose of glyburide is
Rationale:
B: 1.25-20 mg/day. Glyburide is typically prescribed within this dosage range, as it effectively lowers blood sugar levels while minimizing the risk of side effects associated with higher doses. Clinical guidelines support this range for optimal therapeutic outcomes.
A: 0.5-2 mg/day. This dosage is too low for glyburide, as it would likely fail to achieve adequate blood glucose control in patients requiring medication for diabetes management.
C: 50-100 mg/day. This dosage exceeds the established therapeutic range for glyburide, increasing the likelihood of adverse effects and potential toxicity in patients using this medication for blood sugar regulation.
D: 200 mg/day. Such a high dosage is not supported by clinical guidelines and could lead to serious health risks, including hypoglycemia and other complications in diabetic patients.
There is no alternative to insulin therapy for
Rationale:
There is no alternative to insulin therapy for all insulin dependent diabetes mellitus (IDDM) patients. IDDM patients require insulin for glucose regulation, as their bodies cannot produce sufficient insulin, making alternative treatment options ineffective for managing their condition.
B: All noninsulin dependent diabetes mellitus (NIDDM) patients. NIDDM patients often manage their diabetes through oral medications and lifestyle changes, making insulin unnecessary for many individuals in this category.
C: NIDDM patients not controlled by a sulfonylurea drug. Insulin therapy might be one option, but other alternatives exist, such as different classes of oral medications, which can effectively manage blood sugar levels.
D: NIDDM patients not controlled by a biguanide drug. Similar to sulfonylureas, patients can explore various other medications or combinations to achieve glucose control without immediately resorting to insulin therapy.
The present status of oral hypoglycaemics in diabetes mellitus is
Rationale:
Oral hypoglycaemics are used first in most uncomplicated mild to moderate type II diabetics. This approach is standard practice as these medications effectively manage blood glucose levels without necessitating insulin therapy for these patient groups.
A: They are the first choice drugs in all cases. Not all diabetes cases are suitable for oral medications, particularly more complex or advanced situations requiring insulin.
B: They should be prescribed only if the patient refuses insulin injections. This option overlooks the appropriateness of oral hypoglycaemics for many patients who do not need insulin therapy at all.
C: They are used only in type I diabetes mellitus. Oral hypoglycaemics are not effective for type I diabetes, as this condition requires insulin therapy due to the absence of insulin production.
Excessive use of tolbutamide will lead to
Rationale:
Prolonged hypoglycemia. Excessive use of tolbutamide, a sulfonylurea, triggers persistent insulin secretion, which can lower blood glucose levels to dangerous extremes, resulting in prolonged hypoglycemia, a serious condition requiring immediate attention.
A: Diarrhea. While gastrointestinal disturbances can occur with various medications, tolbutamide is primarily associated with blood glucose regulation, not digestive issues, making diarrhea an unlikely consequence of its excessive use.
C: Tolerance to alcohol. Tolbutamide does not influence alcohol tolerance as its primary action is glucose metabolism. Therefore, excessive use does not alter the body's response to alcohol consumption.
D: Acidosis. Tolbutamide does not directly cause metabolic acidosis. Its mechanism revolves around insulin secretion and glucose control, rather than affecting the body's acid-base balance, ruling out acidosis as a side effect.
Incorporation of vasoconstrictor substance in a solution of a drug to be injected subcutaneously retards absorption. This principal is utilized in combination of
Rationale:
Epinephrine with local anaesthetics. This combination prolongs the effect of the local anesthetic by constricting blood vessels, which slows absorption into the bloodstream, thus enhancing localized pain relief during medical procedures.
B: Epinephrine with I.V. glucose. This combination does not involve vasoconstriction for absorption delay, as glucose is typically administered for rapid energy replenishment rather than for prolonged local effects.
C: With vaccines. Vaccines often require rapid absorption to induce a timely immune response, making the incorporation of vasoconstrictors counterproductive in this context.
D: With insulin. Insulin absorption is generally facilitated for immediate action in managing blood sugar levels, where vasoconstriction would hinder its effectiveness by delaying absorption.
Current criteria used in the diagnosis of diabetes mellitus (DM) include all of the following symptoms except
Rationale:
D: Tinnitus is not a recognized symptom in the diagnosis of diabetes mellitus. The current criteria focus on metabolic symptoms, particularly elevated blood sugar levels and their physiological effects, rather than auditory issues.
A: Fasting hyperglycemia indicates high blood sugar levels after an overnight fast, a key diagnostic criterion for diabetes mellitus.
B: Polyuria, or excessive urination, arises from high glucose levels, leading the kidneys to excrete more urine, which is a significant symptom of diabetes mellitus.
C: Polydipsia refers to increased thirst resulting from dehydration due to frequent urination, making it a common symptom associated with diabetes mellitus.
The insulin preparation of choice in diabetic ketoacidosis is
Rationale:
Regular insulin is the insulin preparation of choice in diabetic ketoacidosis.
Regular insulin provides rapid onset and effective glucose control, making it ideal for correcting severe hyperglycemia and metabolic derangements in diabetic ketoacidosis. Its short half-life allows for precise titration and monitoring of blood glucose levels, essential for managing this critical condition.
B: Lente insulin This long-acting insulin does not offer the rapid action necessary for acute management of diabetic ketoacidosis, delaying effective treatment.
C: Isophane insulin As an intermediate-acting insulin, isophane cannot address the immediate insulin needs in diabetic ketoacidosis, leading to inadequate glucose control during emergencies.
D: Monocomponent insulin This term is vague and not a recognized insulin type for acute management, lacking the specificity needed for treating diabetic ketoacidosis effectively.
Diabetic ketoacidosis is best managed by
Rationale:
Crystalline insulin given intravenously. This method provides rapid action, allowing for precise control of blood glucose levels in diabetic ketoacidosis, which is essential for effectively managing this life-threatening condition.
B: Human insulin given intramuscular. Intramuscular administration is slower than intravenous, leading to delayed action that may not adequately address the urgent metabolic crisis presented in diabetic ketoacidosis.
C: Lente insulin given subcutaneously. Subcutaneous delivery is too slow to effectively manage the acute state of hyperglycemia and acidosis seen in diabetic ketoacidosis, compromising patient safety and recovery.
D: Isophane insulin given intradermally. Intradermal administration is inappropriate for treating diabetic ketoacidosis, as it does not provide the necessary rapid absorption required to stabilize the patient’s condition effectively.
Human insulins are obtained by the following sources/methods except
Rationale:
Human insulins are obtained by enzyme modification of pork insulin.
The use of enzyme modification refers to the process of altering pork insulin to create a form that mimics human insulin, making it a viable source. In contrast, cadaver pancreas does not provide a standardized or ethical source for human insulin production.
B: Proinsulin recombinant bacterial utilizes genetically modified bacteria to produce human insulin, thus representing a legitimate method for insulin synthesis.
C: Precursor yeast recombinant involves using yeast to generate insulin precursors, which can be processed into human insulin, indicating a valid production technique.
D: Enzyme modification of pork insulin successfully transforms porcine insulin into a human-compatible form, making it a recognized method for producing insulin.
Which of the following may increase the insulin need of diabetics?
Rationale:
D: Prednisone may increase the insulin need of diabetics due to its corticosteroid properties, which can elevate blood glucose levels by promoting gluconeogenesis and reducing insulin sensitivity, thus necessitating higher insulin doses.
A: Isoniazid primarily affects tuberculosis treatment and does not significantly influence blood sugar levels or insulin requirements in diabetics, making it irrelevant in this context.
B: Penicillin is an antibiotic that targets bacterial infections and has no direct metabolic effects on insulin levels or diabetes management, thus not impacting insulin needs.
C: Glyceryl guaiacolate is an expectorant used for respiratory issues and does not affect glucose metabolism or insulin requirements, rendering it unrelated to diabetes management.
Compared to pork/beef insulins, the human insulins
Rationale:
Human insulins have a faster kinetics of absorption and elimination compared to pork and beef insulins. This rapid action allows for better blood glucose control and minimizes the risk of prolonged hypoglycemia.
A: Are more potent. Potency is not the distinguishing feature; the effectiveness of human insulins is primarily due to their improved pharmacokinetics rather than a higher potency level.
C: Have longer biological action half-life. Human insulins generally exhibit a shorter biological half-life, facilitating quicker absorption and acting more promptly than the longer-lasting effects associated with pork and beef insulins.
D: Penetrate blood-brain barrier more efficiently. Insulin's primary role is in glucose metabolism, and it does not significantly traverse the blood-brain barrier, rendering this option irrelevant to its pharmacological properties.
Nephrogenic diabetes insipidus is seen with
Rationale:
Nephrogenic diabetes insipidus is seen with Demeclocycline. Demeclocycline is known to induce nephrogenic diabetes insipidus by inhibiting the action of antidiuretic hormone, leading to impaired water reabsorption in the kidneys, which is a hallmark of this condition.
B: Doxycycline does not affect kidney response to antidiuretic hormone; it primarily functions as an antibiotic without inducing nephrogenic diabetes insipidus.
C: Minocycline lacks the specific properties to interfere with water reabsorption in the kidneys, thus it does not lead to nephrogenic diabetes insipidus.
D: Oxytetracycline does not possess the mechanism to induce nephrogenic diabetes insipidus and is mainly used as an antibiotic for bacterial infections.
Preferred route of insulin is
Rationale:
Subcutaneous. Insulin is most effectively administered subcutaneously, as this route allows for appropriate absorption into the bloodstream, mimicking the natural release of insulin by the pancreas and providing effective blood sugar control.
A: Oral. Insulin cannot be taken orally due to degradation by stomach acids and enzymes, which prevent it from reaching systemic circulation effectively.
C: Sublingual. While sublingual administration bypasses digestion, insulin's molecular structure does not allow sufficient absorption through the mucous membranes, rendering this method ineffective for systemic delivery.
D: Enteric coated tabs. Enteric-coated tablets are designed for oral medications that require protection from stomach acid, making them unsuitable for insulin, which cannot be effectively absorbed via this route.
Sulfonylureas are more commonly used than biguanides as oral hypoglycaemics because
Rationale:
Sulfonylureas are more commonly used than biguanides as oral hypoglycaemics because biguanides are less efficacious.
Biguanides primarily improve insulin sensitivity but may not effectively lower blood glucose levels for all patients, making them less favorable compared to sulfonylureas, which have a stronger glucose-lowering effect in diverse populations.
B: Sulfonylureas lower blood sugar in both IDDM and NIDDM patients. This statement is misleading, as sulfonylureas are primarily effective in NIDDM patients and not recommended for IDDM.
C: Sulfonylureas also aid weight reduction in obese diabetics. While sulfonylureas may provide some metabolic benefits, they typically do not promote weight loss and can even cause weight gain in some individuals.
D: Biguanides are prone to precipitate ketoacidosis. This is inaccurate, as biguanides are actually known to reduce the risk of ketoacidosis, typically associated with insulin deficiency rather than their use.
The agent with negligible mineralocorticoid effect is
Rationale:
Betamethasone is the agent with negligible mineralocorticoid effect. This corticosteroid primarily exerts potent anti-inflammatory properties with minimal impact on electrolyte balance, making it suitable for conditions requiring effective inflammation control without significant mineralocorticoid side effects.
A: Prednisone has notable mineralocorticoid effects, influencing sodium and water retention, thus affecting fluid balance and blood pressure significantly.
C: Fludrocortisone is specifically designed as a potent mineralocorticoid, actively promoting sodium retention and potassium excretion, which is contrary to negligible effects.
D: Cortisol, a natural glucocorticoid, possesses considerable mineralocorticoid activity, affecting renal function and fluid homeostasis, making it unsuitable for this classification.
Aldosterone enhances Na+ reabsorption in renal tubules by
Rationale:
Aldosterone enhances Na+ reabsorption in renal tubules by inducing the synthesis of Na+ K+ ATPase. This hormone increases the number of Na+ K+ ATPase pumps, facilitating sodium reabsorption and potassium secretion, crucial for maintaining electrolyte balance and blood pressure regulation in the body.
A: Stimulating carbonic anhydrase This option misattributes the mechanism, as carbonic anhydrase primarily facilitates bicarbonate reabsorption and does not directly influence sodium reabsorption in renal tubules.
B: Inhibiting Na+ K+ ATPase This choice contradicts the action of aldosterone; inhibiting this enzyme would decrease sodium reabsorption and potassium secretion, undermining aldosterone's primary function in renal physiology.
D: Promoting K+ secretion While aldosterone does promote potassium secretion, this option does not address the mechanism of sodium reabsorption, which is the main focus of the question regarding aldosterone's action.
The insulin receptor is
Rationale:
The insulin receptor is a tyrosine protein kinase receptor. This is accurate as the receptor initiates a signaling cascade upon insulin binding by autophosphorylation of tyrosine residues, crucial for glucose metabolism regulation.
B: G protein coupled receptor. This classification pertains to receptors that activate intracellular signaling through G proteins, which is not applicable to the insulin receptor's mechanism.
C: Ion channel regulating receptor. Ion channels facilitate the flow of ions across membranes but do not describe the insulin receptor's function, which relies on phosphorylation events.
D: None of these. This option suggests that the insulin receptor does not fit any established category, which is misleading as it is specifically a tyrosine protein kinase receptor.
A mass of adipose tissue that develops at the injection site is usually due to the patients neglect in rotating the insulin injection site. This is known as
Rationale:
Lipohypertrophy. This condition arises from the accumulation of fat at insulin injection sites, often resulting from repetitive use of the same area, leading to localized thickening of adipose tissue.
A: Lipoatrophy. This term refers to the loss of fat tissue rather than its accumulation, which does not align with the description of tissue buildup at injection sites.
B: Hypertrophic degenerative adiposity. This phrase lacks specificity regarding insulin injections and does not accurately describe the localized fat increase typically observed in lipohypertrophy cases.
D: Atrophic skin lesion. This terminology implies skin thinning or loss rather than the fat accumulation seen in lipohypertrophy, making it an inappropriate description of the condition.
Metformin
Rationale:
Metformin does not cause hypoglycemia even in large doses. This is due to its mechanism of action, which primarily involves reducing hepatic glucose production and enhancing insulin sensitivity, rather than stimulating insulin release directly from the pancreas, thus minimizing the risk of low blood sugar levels.
B: Should not be combined with glipizide. While caution is advised, combining metformin with glipizide can be beneficial for many patients when appropriately managed, enhancing overall glycemic control.
C: Is contraindicated in obese NIDDM patients. Metformin is often recommended for obese individuals with non-insulin-dependent diabetes mellitus due to its benefits in weight management and improved insulin sensitivity.
D: Causes release of insulin from the pancreas. Metformin primarily works by decreasing glucose production in the liver and increasing insulin sensitivity, rather than stimulating the pancreas to release insulin directly.
Sulfonylureas are a primary mode of therapy in the treatment of
Rationale:
Sulfonylureas are a primary mode of therapy in the treatment of Non-insulin-dependent (type 2) DM patients.
Sulfonylureas stimulate insulin secretion from pancreatic beta cells, effectively lowering blood glucose levels in type 2 diabetes. They are particularly suitable for patients who still produce some insulin and need assistance in managing their blood sugar levels, making them a first-line treatment choice for this condition.
A: Insulin-dependent (type 1) diabetes mellitus (IDDM) patients. Type 1 diabetes requires insulin therapy due to the absence of insulin production, rendering sulfonylureas ineffective for these individuals.
B: Diabetic patients experiencing severe hepatic or renal dysfunction. Sulfonylureas can cause complications in patients with significant liver or kidney issues, where alternative treatments may be safer and more effective.
C: Diabetic pregnant women. The safety profile of sulfonylureas during pregnancy is not well-established, making them less desirable compared to insulin or other medications deemed safer for use in pregnant patients.
The antidiabetic agent most likely to cause lactic acidosis is
Rationale:
B: Phenformin is the antidiabetic agent most likely to cause lactic acidosis due to its propensity to accumulate in patients with renal impairment, leading to increased risk of lactic acid buildup in the bloodstream.
A: Chlorpropamide does not have a notable association with lactic acidosis and primarily works by stimulating insulin secretion from the pancreas, rather than affecting lactate levels.
C: Glipizide, a sulfonylurea, enhances insulin release from the pancreas and has minimal risk of causing lactic acidosis, making it a safer option for patients with renal concerns.
D: Metformin is associated with lactic acidosis, but it is significantly less likely than Phenformin, which has been largely withdrawn from the market due to its higher risk profile.
The most useful glucose test used in monitoring diabetes mellitus (DM) therapy is
Rationale:
Blood monitoring is the most useful glucose test used in monitoring diabetes mellitus (DM) therapy.
Blood monitoring provides real-time glucose levels, allowing for precise management of insulin and dietary needs, which is crucial for effective diabetes control. This method helps track fluctuations and maintain target glucose levels, ensuring optimal therapeutic outcomes and minimizing complications associated with diabetes.
A: Urine monitoring offers indirect glucose measurements and does not reflect immediate changes in blood sugar levels, making it less effective for real-time diabetes management.
C: Renal function monitoring assesses kidney health rather than glucose levels, failing to provide necessary insights into diabetes management or glucose regulation.
D: Cardiovascular monitoring focuses on heart health and does not evaluate glucose levels, which are essential for the effective management of diabetes mellitus.
Select the drug which tends to reverse insulin resistance by increasing cellular glucose transporters.
Rationale:
Troglitazone tends to reverse insulin resistance by increasing cellular glucose transporters. This drug, classified as a thiazolidinedione, enhances insulin sensitivity by activating peroxisome proliferator-activated receptors (PPARs), leading to improved glucose uptake in peripheral tissues.
A: Glibenclamide Stimulates insulin secretion from the pancreas rather than directly enhancing cellular glucose transporters, thus not effectively addressing insulin resistance mechanisms.
C: Acarbose Inhibits carbohydrate absorption in the intestines, which does not influence insulin sensitivity or increase glucose transporter activity in cells.
D: Prednisolone Functions as a corticosteroid, promoting gluconeogenesis and potentially worsening insulin resistance rather than facilitating glucose uptake by increasing transporter levels.
In a patient of diabetes mellitus maintained on insulin therapy, administration of the following drug can vitiate glycaemia control.
Rationale:
Prednisolone can vitiate glycaemia control in patients with diabetes mellitus on insulin therapy. This corticosteroid increases insulin resistance and can lead to elevated blood glucose levels, complicating diabetes management significantly.
B: Prazosin primarily acts as an antihypertensive and does not significantly influence glucose metabolism or insulin sensitivity in diabetic patients, maintaining glycemic control.
C: Paracetamol is an analgesic and antipyretic medication that does not interfere with insulin action or glucose levels, thus having no effect on glycaemia control.
D: Phenytoin is an anticonvulsant that may cause minor fluctuations in glucose levels, but it does not substantially impact insulin efficacy or overall glycemic management in diabetics.
Guargum limits post-prandial glycaemia by
Rationale:
Guargum limits post-prandial glycaemia by slowing carbohydrate absorption from the intestine. This mechanism decreases the rate at which glucose enters the bloodstream, thus preventing rapid spikes in blood sugar levels after meals.
A: Inhibiting intestinal brush border α glucosidases This option focuses on enzyme inhibition, which does not directly relate to the slower absorption process that guargum facilitates in the intestine.
C: Releasing incretins from the intestine This choice suggests a hormone-related mechanism, but guargum’s primary action is through the modulation of carbohydrate absorption rather than hormone release.
D: Promoting uptake of glucose into skeletal muscles This option implies enhanced glucose utilization, which is not the primary function of guargum; its main role is to regulate absorption in the gut.
The treatment of gestational diabetes would comprise of
Rationale:
Insulin. This treatment is preferred for gestational diabetes as it effectively manages blood glucose levels without crossing the placenta, ensuring the safety of both the mother and the fetus.
A: Glibenclamide. This oral medication is typically used for type 2 diabetes and may not be suitable during pregnancy due to potential adverse effects on fetal development.
B: Chlorpropamide. This sulfonylurea is contraindicated in pregnancy, as it can lead to serious complications, including neonatal hypoglycemia and potential teratogenic effects on the developing fetus.
C: Glipizide. While effective for type 2 diabetes, this medication is not recommended for gestational diabetes due to its ability to cross the placenta, posing risks to the fetus.
The sulfonylurea with a relatively longer duration of action is
Rationale:
Chlorpropamide has a relatively longer duration of action among sulfonylureas. This extended effect allows for more stable blood glucose control over time, making it suitable for patients needing prolonged glycemic management.
B: Tolbutamide has a shorter duration of action, thus requiring more frequent dosing and potentially leading to less consistent blood glucose levels throughout the day.
C: Glibenclamide has a moderate duration of action, but it does not surpass that of chlorpropamide, making it less effective for prolonged glycemic control in comparison.
D: Glipizide generally has a shorter duration of action, necessitating multiple daily doses, which can be inconvenient for patients seeking a more sustained release of medication.
For increasing the excretion of weakly acidic drugs, urine should be made
Rationale:
Urine should be made alkaline.
Alkaline urine enhances the ionization of weakly acidic drugs, promoting their solubility and subsequent excretion. The increased pH reduces the reabsorption of these drugs in the renal tubules, facilitating their elimination from the body.
B: At neutral pH. Neutral pH does not significantly enhance the ionization of weakly acidic drugs, resulting in less efficient excretion compared to alkaline conditions.
C: Acidic. Acidic urine favors the non-ionized form of weakly acidic drugs, which can be reabsorbed in the renal tubules, thus reducing their excretion.
D: pH does not affect the urinary excretion of acidic drugs. This statement overlooks the critical role of urine pH in influencing the ionization and solubility of weakly acidic drugs, impacting their excretion rate.
Longest acting insulin is
Rationale:
D: Protamine zinc insulin provides the longest duration of action among available insulin types, allowing for extended blood glucose control. Its formulation combines protamine and zinc, which slow absorption and prolong effects in the body.
A: Insulin zinc suspension offers a moderate duration but does not extend as long as protamine zinc insulin, making it less effective for prolonged glycemic control.
B: Isophane insulin, while a longer-acting option, does not match the extended duration provided by protamine zinc insulin, leading to shorter efficacy in managing blood sugar levels.
C: Globin zinc insulin has limited use and does not provide the same prolonged action as protamine zinc insulin, resulting in less stability for blood glucose management over time.
Which of the following is true of acarbose?
Rationale:
Acarbose limits postprandial hyperglycaemia in diabetes. This action occurs by inhibiting intestinal enzymes that digest carbohydrates, leading to a slower glucose absorption rate and thereby reducing blood sugar spikes after meals.
A: It reduces absorption of glucose from intestines. While acarbose affects glucose absorption, its primary role is to slow carbohydrate digestion, not merely to reduce absorption levels directly.
B: It produces hypoglycaemia in normal as well as diabetic subjects. Acarbose typically does not induce hypoglycaemia on its own; its mechanism is designed to moderate glucose levels rather than lower them excessively.
D: It raises circulating insulin levels. Acarbose does not elevate insulin levels; instead, it primarily focuses on managing glucose levels post-meal without directly affecting insulin secretion.
Glucagon release from pancreas is stimulated by
Rationale:
Glucagon release from the pancreas is stimulated by adrenaline. Adrenaline activates the sympathetic nervous system, prompting the pancreas to secrete glucagon, which raises blood glucose levels during stress or low glucose situations.
A: High blood glucose level A high blood glucose level signals the pancreas to produce insulin, not glucagon, as the body aims to lower excess glucose in the bloodstream.
B: Insulin Insulin's primary role is to facilitate glucose uptake into cells, leading to decreased blood glucose levels, which does not promote glucagon secretion from the pancreas.
C: Somatostatin Somatostatin inhibits the release of both glucagon and insulin, acting as a regulatory hormone that decreases the activity of the pancreas rather than stimulating glucagon release.
Diuretic effective in diabetes insipidus is
Rationale:
Thiazides are effective in diabetes insipidus. They help reduce urine output by enhancing sodium reabsorption in the distal convoluted tubule, thus managing the condition effectively even though they are typically used for hypertension.
B: Loop diuretic Loop diuretics primarily act on the ascending loop of Henle and are not suitable for treating diabetes insipidus, as they increase urine output rather than decreasing it.
C: Mercurial diuretic Mercurial diuretics are outdated and not commonly used in clinical practice today; they do not address the underlying issues of diabetes insipidus effectively.
D: Carbonic anhydrase inhibitor Carbonic anhydrase inhibitors primarily reduce bicarbonate reabsorption, leading to metabolic acidosis, which does not provide the necessary therapeutic effect for managing diabetes insipidus.
Insulin
Rationale:
Insulin promotes synthesis of triglycerides. This hormone facilitates the conversion of glucose into fatty acids, which are then assembled into triglycerides, thus playing a crucial role in lipid metabolism and energy storage.
A: Release is enhanced by somatostatin. Somatostatin functions to inhibit insulin secretion, creating an opposing effect rather than enhancing the release of insulin from the pancreas.
B: Has an identical chemical structure in all the species. Insulin varies among species, with structural differences that can affect its function, highlighting the diversity in hormonal regulation across organisms.
C: Release from the pancreas occurs only in the postprandial state. Insulin is also released during fasting, though at lower levels, to maintain glucose homeostasis, not exclusively in response to food intake.
The hypoglycaemic action of sulfonylureas is likely to be attenuated by the concurrent use of
Rationale:
Concurrent use of hydrochlorothiazide is likely to attenuate the hypoglycaemic action of sulfonylureas due to its potential to increase blood glucose levels by promoting insulin resistance and altering fluid balance.
B: Propranolol may mask hypoglycaemic symptoms but does not directly influence the efficacy of sulfonylureas, thus not affecting their hypoglycaemic action.
C: Chloramphenicol can enhance the effects of sulfonylureas, potentially increasing hypoglycaemia, rather than diminishing it, making it an unlikely choice.
D: Aspirin does not significantly impact blood glucose levels or sulfonylurea efficacy, and its antiplatelet effects do not interfere with hypoglycaemia management.
Which of the following statements concerning insulin replacement therapy is most accurate?
Rationale:
Counting or regulating carbohydrate consumption is a necessity for all diabetic patients. This practice helps manage blood glucose levels effectively, ensuring that insulin therapy aligns with dietary intake and promotes overall glycemic control.
A: Most commercial insulin products vary little with respect to time, course, and duration of hypoglycemic activity. Different insulin formulations have distinct pharmacokinetics, leading to variations in their action profiles and onset of effects.
B: Regular insulins cannot be mixed with NPH (isophane insulin suspension). In fact, regular insulin can be mixed with NPH, allowing for tailored therapy that provides both immediate and prolonged effects.
C: Regular insulin cannot be given intravenously. Regular insulin is, in fact, commonly administered intravenously for precise control of blood glucose levels in various clinical situations.
The most common adverse reaction to insulin is
Rationale:
Hypoglycaemia. This reaction occurs when insulin lowers blood glucose levels excessively, which is the most frequently observed adverse effect among individuals using insulin for diabetes management, necessitating careful monitoring and dosage adjustments.
B: Lipodystrophy. While this condition can occur due to insulin injections, it is less prevalent compared to hypoglycaemia, primarily affecting fat distribution rather than immediate glucose levels in the bloodstream.
C: Urticaria. This skin reaction does happen occasionally in response to insulin but is not as common as hypoglycaemia, which directly impacts blood sugar levels and affects many insulin users.
D: Angioedema. This severe allergic reaction can occur with insulin but is rare and not as frequently encountered as hypoglycaemia, which presents more immediate and widespread concerns for patients.
The second generation sulfonylurea hypoglycaemics differ from the first generation one in that they
Rationale:
Second generation sulfonylurea hypoglycaemics are more potent. This increased potency allows for lower doses to achieve the desired blood sugar-lowering effects, making them more effective and efficient compared to first-generation agents.
B: Are longer acting. While some second-generation sulfonylureas may have varying durations, the defining characteristic is their potency rather than extended action compared to their predecessors.
C: Do not lower blood sugar in nondiabetic subjects. Both generations can affect blood sugar levels in nondiabetics; however, this does not differentiate the second generation from the first.
D: Are less prone to cause hypoglycaemic reaction. Hypoglycaemia risk persists across generations, with second-generation sulfonylureas being more potent, which can actually increase the likelihood of this side effect.
Patients taking chlorpropamide should avoid products containing
Rationale:
Patients taking chlorpropamide should avoid products containing ethanol. Ethanol can stimulate an adverse reaction with chlorpropamide, leading to severe hypoglycemia and other complications, making its consumption particularly dangerous for patients on this medication.
A: Acetaminophen Acetaminophen does not interact negatively with chlorpropamide, and patients can generally use it for pain relief without significant risk.
C: Vitamin A Vitamin A does not pose risks when taken with chlorpropamide, as there are no documented interactions that would affect blood sugar levels or medication efficacy.
D: Penicillins Penicillins are antibiotics that do not interfere with chlorpropamide's action, making them a safe choice for treating infections in patients using this medication.
Which of the following features disfavors use of oral hypoglycaemics in diabetes mellitus?
Rationale:
Insulin requirement more than 40 U/day. This level of insulin requirement indicates significant insulin resistance or beta-cell dysfunction, suggesting that oral hypoglycemics may not adequately control blood glucose levels, making insulin therapy more appropriate for effective management.
A: Age at onset of disease over 40 years. This characteristic alone does not inherently limit the effectiveness of oral hypoglycemics, as many individuals can still respond well to these medications.
C: Fasting blood sugar level between 100-200 mg/dl. This range does not disqualify the use of oral hypoglycemics, as many patients within this level can achieve glycemic control with appropriate medications.
D: Associated obesity. Obesity may actually enhance the effectiveness of certain oral hypoglycemics, as some can promote weight loss or improve insulin sensitivity, making this not a disfavoring factor.
Insulin resistance can be overcome by the use of
Rationale:
D: Monocomponent insulin preparations effectively enhance insulin sensitivity, allowing for better glucose uptake by cells. This targeted approach helps restore normal metabolic function and mitigates the adverse effects of insulin resistance.
A: Corticosteroids can induce insulin resistance as a side effect, potentially exacerbating the condition rather than improving it. Their action primarily involves modulating inflammation, not directly addressing insulin sensitivity.
B: Tolbutamide stimulates insulin secretion but does not directly resolve insulin resistance. Its mechanism primarily revolves around enhancing pancreatic function instead of improving cellular response to insulin.
C: Protamine is used to prolong the action of insulin rather than combat insulin resistance. Its role is primarily as an additive in insulin formulations, not a treatment for resistance itself.
Metformin is preferred over phenformin because
Rationale:
Metformin is less liable to cause lactic acidosis.
This advantage stems from metformin’s pharmacological profile, which allows for effective glucose regulation with a significantly reduced risk of lactic acid buildup, making it safer for patients, particularly those with renal issues.
A: It is more potent. Potency does not inherently determine the safety or appropriateness of a medication, especially in the context of lactic acidosis risk.
C: It does not interfere with vitamin B12 absorption. While this is relevant, it does not address the critical issue of lactic acidosis risk associated with phenformin.
D: It is not contraindicated in patients with kidney disease. Although metformin is used cautiously in renal impairment, the primary concern is its safety regarding lactic acidosis, not solely its contraindications.
The insulin receptor is a
Rationale:
The insulin receptor is a tyrosine protein kinase receptor. This receptor facilitates cellular responses to insulin by initiating a phosphorylation cascade, which ultimately leads to glucose uptake and metabolism, playing a crucial role in energy homeostasis.
A: Ion channel regulating receptor This describes receptors that allow ions to pass through membranes, which is fundamentally different from the signaling mechanism of the insulin receptor.
C: G-protein coupled receptor This type of receptor activates intracellular signaling through G-proteins, which is not how the insulin receptor operates, as it directly phosphorylates substrates instead.
D: None of these This option suggests that the insulin receptor does not fit any provided classifications, which contradicts its established identity as a tyrosine protein kinase receptor.
Which of the following is a neuroglucopenic symptom of hypoglycaemia?
Rationale:
Abnormal behavior. Neuroglucopenic symptoms arise from insufficient glucose affecting brain function, leading to cognitive disruptions and altered behavior. This indicates the brain's direct response to low glucose levels, distinguishing it from other symptoms.
A: Sweating Excessive sweating is a sympathoadrenal response to hypoglycemia, primarily triggered by the body’s fight or flight mechanism rather than a direct effect on brain glucose availability.
B: Palpitation Heart palpitations stem from adrenaline release during hypoglycemia, signifying autonomic nervous system activation instead of direct neuroglucopenic effects on cognitive functions and behavior.
C: Tremor Tremors occur due to adrenergic stimulation, reflecting the body’s physiological response to stress rather than the brain's cognitive impairment caused by low glucose levels.
Sulfonylureas do not lower blood sugar level in
Rationale:
Sulfonylureas do not lower blood sugar levels in insulin dependent diabetics. This is because these medications stimulate insulin release from the pancreas, which is ineffective in individuals whose bodies do not produce insulin, making their action irrelevant in this context.
A: Nondiabetics Nondiabetics do not have elevated blood sugar levels requiring treatment, so sulfonylureas would have no impact on their glucose levels or metabolic processes.
B: Noninsulin dependent diabetics Noninsulin dependent diabetics can often produce insulin, allowing sulfonylureas to effectively lower blood sugar by enhancing the release of their own insulin.
D: None of these This option implies that sulfonylureas lower blood sugar in all categories, which is inaccurate as their effect is specifically limited in insulin dependent diabetics.
The duration of action of insulin-zinc suspension (lente insulin) is
Rationale:
The duration of action of insulin-zinc suspension (lente insulin) is 20-24 hours. This extended duration is due to the formulation's unique properties, allowing for a gradual release of insulin into the bloodstream, providing sustained glycemic control over a longer period compared to shorter-acting insulins.
A: 2-4 hours This option suggests a very brief action, which does not align with the pharmacokinetics of lente insulin, known for its longer-lasting effects.
B: 8-10 hours This timeframe underestimates the prolonged effect of lente insulin, which is designed to manage blood sugar levels effectively for a significantly longer duration.
D: 30-36 hours This duration exceeds the known pharmacological properties of lente insulin, which does not provide action for such an extended period, indicating a misunderstanding of its effectiveness.
A diabetic on oral hypoglycaemic drug chlorpropamide, suffered from enteric fever and was prescribed chloramphenicol. He developed severe hypoglycaemia. This is because
Rationale:
Chloramphenicol inhibits the metabolism of chlorpropamide. This leads to increased levels of chlorpropamide in the bloodstream, enhancing its hypoglycaemic effect and causing severe hypoglycaemia in the diabetic patient.
A: Chloramphenicol itself has mild hypoglycaemic effect. While chloramphenicol may have some effects on glucose metabolism, its primary action in this context relates to chlorpropamide's metabolism, not direct hypoglycaemia.
B: Chloramphenicol increases the absorption of chlorpropamide. Absorption enhancement does not explain severe hypoglycaemia; rather, it is the inhibition of drug metabolism that results in heightened hypoglycaemic effects.
C: Chloramphenicol causes release of insulin. Chloramphenicol does not directly stimulate insulin release; instead, it affects the metabolism of chlorpropamide, leading to increased insulin action and hypoglycaemia.
Sulfonylurea hypoglycaemics act by
Rationale:
Sulfonylurea hypoglycaemics act by both increasing insulin secretion from the pancreas and reversing down-regulation of insulin receptors.
This answer is accurate as sulfonylureas stimulate pancreatic beta cells, enhancing insulin release, and also improve insulin receptor sensitivity, effectively lowering blood glucose levels in patients with type 2 diabetes.
A: Reducing intestinal absorption of glucose fails to capture the primary mechanism of sulfonylureas, which focus on insulin secretion rather than influencing glucose absorption in the digestive tract.
B: Increasing insulin secretion from pancreas describes only part of the action of sulfonylureas, neglecting their role in reversing insulin receptor down-regulation, which is crucial for their effectiveness.
C: Reversing down-regulation of insulin receptors alone overlooks the importance of stimulating insulin secretion, making this option incomplete in explaining the overall mechanism of sulfonylurea medications.
The standard recommended dose of glyburide is
Rationale:
B: 1.25-20 mg/day. This range accurately reflects the standard recommended dosage of glyburide for effective management of blood sugar levels in patients with type 2 diabetes, ensuring optimal therapeutic outcomes.
A: 0.5-2 mg/day. This dosage is significantly lower than the established therapeutic range, potentially leading to inadequate glycemic control in individuals requiring medication for diabetes management.
C: 50-100 mg/day. This dosage is excessively high, raising the risk of severe hypoglycemia and side effects, which can compromise patient safety and overall treatment effectiveness.
D: 200 mg/day. Such a dosage exceeds recommended limits, which can result in dangerous side effects and is not supported by clinical guidelines for glyburide administration.
There is no alternative to insulin therapy for
Rationale:
There is no alternative to insulin therapy for all insulin dependent diabetes mellitus (IDDM) patients. IDDM patients require insulin for blood glucose regulation due to their inability to produce adequate insulin, making alternative therapies ineffective in managing their condition and preventing complications related to uncontrolled diabetes.
B: All noninsulin dependent diabetes mellitus (NIDDM) patients. NIDDM patients can often manage their condition with oral medications and lifestyle changes, making insulin therapy unnecessary for many individuals with this type of diabetes.
C: NIDDM patients not controlled by a sulfonylurea drug. While these patients may require insulin, they could potentially respond to other medications or treatments before resorting to insulin therapy, demonstrating alternative options exist.
D: NIDDM patients not controlled by a biguanide drug. Similar to sulfonylureas, patients not responding to biguanides might find effective management through alternative therapies, thus not necessitating insulin as the sole option.
The present status of oral hypoglycaemics in diabetes mellitus is
Rationale:
They are used first in most uncomplicated mild to moderate type II diabetics. Oral hypoglycaemics are preferred initial therapies for managing type II diabetes due to their effectiveness in controlling blood glucose levels without requiring injections, making them more acceptable for patients in these scenarios, especially when insulin is not necessary.
A: They are the first choice drugs in all cases. Not all diabetes cases warrant oral hypoglycaemics; complex cases may require insulin or other therapies for optimal management and safety.
B: They should be prescribed only if the patient refuses insulin injections. This limits the use of oral hypoglycaemics unnecessarily, as they are effective first-line treatments that can be used before considering insulin therapy in appropriate cases.
C: They are used only in type I diabetes mellitus. Oral hypoglycaemics are not suitable for type I diabetes; insulin is essential for managing this form of diabetes due to the absence of insulin production.
Excessive use of tolbutamide will lead to
Rationale:
Excessive use of tolbutamide will lead to prolonged hypoglycemia. This medication stimulates insulin secretion, and overuse can cause dangerously low blood sugar levels, resulting in prolonged hypoglycemic episodes that can have serious health consequences.
A: Diarrhea Excessive doses of tolbutamide do not directly induce gastrointestinal disturbances such as diarrhea, which are more commonly associated with other medications or conditions affecting the digestive system.
C: Tolerance to alcohol There is no established connection between tolbutamide use and developing tolerance to alcohol, as these substances interact differently within the body and do not influence each other's effects.
D: Acidosis Tolbutamide does not typically cause metabolic acidosis, which is usually linked to conditions like kidney failure or severe dehydration, rather than the pharmacological actions of this particular medication.
Incorporation of vasoconstrictor substance in a solution of a drug to be injected subcutaneously retards absorption. This principal is utilized in combination of
Rationale:
Epinephrine with local anaesthetics effectively retards absorption when injected subcutaneously by causing vasoconstriction. This mechanism prolongs the anesthetic effect, ensuring a localized and sustained action at the injection site.
B: Epinephrine with I.V. glucose does not relate to absorption retardation, as I.V. administration bypasses subcutaneous absorption. This combination primarily addresses metabolic concerns rather than localized anesthetic effects.
C: With vaccines, the incorporation of a vasoconstrictor is not standard practice. Vaccines are designed for rapid systemic absorption to elicit immune responses, making absorption retardation counterproductive.
D: With insulin, combining vasoconstrictors can hinder the desired rapid absorption of insulin, which is crucial for effective blood sugar regulation. Insulin administration aims for prompt therapeutic action.
Current criteria used in the diagnosis of diabetes mellitus (DM) include all of the following symptoms except
Rationale:
D: Tinnitus is not a recognized symptom for diagnosing diabetes mellitus. The established criteria focus on metabolic indicators and specific symptoms like increased urination and thirst, which are directly related to glucose imbalances. Tinnitus does not correlate with diabetes diagnosis or indicate hyperglycemia.
A: Fasting hyperglycemia indicates elevated blood sugar levels after a period of fasting, a primary criterion for diagnosing diabetes mellitus.
B: Polyuria, or increased urination, results from high glucose levels, which exceed renal thresholds; this is a classic symptom of diabetes.
C: Polydipsia, characterized by excessive thirst, arises when the body compensates for fluid loss due to polyuria, making it a key symptom in diabetes diagnosis.
The insulin preparation of choice in diabetic ketoacidosis is
Rationale:
Regular insulin is the preferred insulin preparation in diabetic ketoacidosis. Its rapid onset and short duration allow for quick adjustments to blood glucose levels, effectively addressing the urgent metabolic imbalances associated with this condition.
B: Lente insulin provides a prolonged action that may not sufficiently address the rapid changes in glucose levels seen in diabetic ketoacidosis.
C: Isophane insulin has an intermediate-acting profile, which delays its action, making it less suitable for the acute management required in diabetic ketoacidosis.
D: Monocomponent insulin lacks the rapid action needed in diabetic ketoacidosis, as it may not adequately control severe hyperglycemia and ketogenesis during this critical condition.
Diabetic ketoacidosis is best managed by
Rationale:
Crystalline insulin given intravenously. This method provides a rapid and effective means to lower blood glucose levels and correct metabolic derangements in diabetic ketoacidosis, ensuring timely intervention and stabilization.
B: Human insulin given intramuscular. This administration route does not offer the necessary speed for acute management, potentially delaying the correction of hyperglycemia and acidosis in critical situations.
C: Lente insulin given subcutaneously. Lente insulin has a slower onset of action, making it unsuitable for the urgent needs presented by diabetic ketoacidosis during treatment.
D: Isophane insulin given intradermally. Intradermal administration lacks proper absorption capabilities for systemic effects and is not appropriate for managing the severe metabolic state seen in diabetic ketoacidosis.
Human insulins are obtained by the following sources/methods except
Rationale:
Human insulins are obtained by the following sources/methods except cadaver pancreas.
Cadaver pancreas is not a viable source for human insulins today, as modern production relies on recombinant DNA technology that utilizes bacteria or yeast, ensuring safer and more efficient insulin manufacturing.
B: Proinsulin recombinant bacterial Utilizes genetically engineered bacteria to produce insulin precursors, allowing for safe and effective human insulin synthesis without reliance on human or animal sources.
C: Precursor yeast recombinant Employs yeast as a host for recombinant DNA techniques, facilitating the production of insulin precursors, which are later modified to form active insulin suitable for human use.
D: Enzyme modification of pork insulin Involves altering pork-derived insulin through enzymatic processes to create a structure similar to human insulin, making it a viable method for insulin production.
Which of the following may increase the insulin need of diabetics?
Rationale:
D: Prednisone significantly raises blood glucose levels, leading to an increased insulin requirement for diabetics. This corticosteroid promotes gluconeogenesis and reduces insulin sensitivity, necessitating higher doses of insulin to maintain glycemic control.
A: Isoniazid has minimal impact on insulin levels and does not typically influence insulin requirements in diabetics. Its primary action is related to tuberculosis treatment rather than glucose metabolism.
B: Penicillin generally does not alter insulin needs, as it primarily functions as an antibiotic. Its mechanism does not directly interfere with insulin production or glucose regulation in diabetic patients.
C: Glyceryl guaiacolate is an expectorant used to relieve coughs and does not affect insulin levels or the metabolic processes related to diabetes management in any significant manner.
Compared to pork/beef insulins, the human insulins
Rationale:
Human insulins have a faster kinetics of absorption and elimination compared to pork and beef insulins. This rapid action allows for better glycemic control, making them more effective in managing blood sugar levels in patients.
A: Are more potent. Potency is not a direct comparison; human insulins are formulated for optimal action rather than enhanced potency over animal-derived insulins.
C: Have longer biological action half-life. Human insulins typically have shorter half-lives, enabling quicker therapeutic effects, which differs from longer-acting animal insulins designed for sustained release.
D: Penetrate blood-brain barrier more efficiently. Insulin's primary role is in glucose regulation, not CNS penetration; human insulins do not exhibit enhanced blood-brain barrier permeability compared to pork or beef insulins.
Nephrogenic diabetes insipidus is seen with
Rationale:
Nephrogenic diabetes insipidus is seen with Demeclocycline. This antibiotic is known to induce nephrogenic diabetes insipidus as it affects the kidneys' response to vasopressin, leading to decreased water reabsorption and increased urine output.
B: Doxycycline This tetracycline has no significant association with nephrogenic diabetes insipidus and primarily functions as an antibiotic without affecting renal water handling mechanisms.
C: Minocycline While minocycline is related to other tetracyclines, it does not have a recognized link to nephrogenic diabetes insipidus or alter kidney function in this manner.
D: Oxytetracycline This antibiotic is not associated with nephrogenic diabetes insipidus and mainly serves antibacterial purposes without impacting renal response to antidiuretic hormone.
Preferred route of insulin is
Rationale:
B: Subcutaneous insulin administration is preferred as it allows for gradual absorption, mimicking the natural insulin release. This route ensures optimal blood glucose control and stability, making it effective for diabetes management.
A: Oral administration of insulin is impractical since digestive enzymes degrade it, preventing adequate absorption and efficacy in regulating blood sugar levels.
C: Sublingual delivery lacks sufficient insulin absorption, making it ineffective for the necessary systemic regulation of glucose levels in diabetic patients.
D: Enteric coated tablets do not provide the required absorption rate for insulin, leading to unpredictable glucose control and inadequate therapeutic response in diabetes management.
Sulfonylureas are more commonly used than biguanides as oral hypoglycaemics because
Rationale:
Sulfonylureas are more commonly used than biguanides as oral hypoglycaemics because biguanides are less efficacious.
Biguanides primarily lower blood sugar by increasing insulin sensitivity but may not achieve adequate glycemic control compared to sulfonylureas, which stimulate insulin secretion directly, making them more effective for many patients.
B: Sulfonylureas lower blood sugar in both IDDM and NIDDM patients. This statement oversimplifies their effectiveness; sulfonylureas are typically used for type 2 diabetes, not type 1.
C: Sulfonylureas also aid weight reduction in obese diabetics. While some patients may experience weight loss, sulfonylureas are more associated with weight gain rather than consistent weight reduction.
D: Biguanides are prone to precipitate ketoacidosis. Biguanides, particularly metformin, are actually used to prevent ketoacidosis, making this statement misleading regarding their safety profile.
The agent with negligible mineralocorticoid effect is
Rationale:
Betamethasone has negligible mineralocorticoid effect. This synthetic glucocorticoid is primarily used for its anti-inflammatory properties and does not significantly influence electrolyte balance or sodium retention, distinguishing it from other corticosteroids.
A: Prednisone possesses some mineralocorticoid activity, affecting fluid and electrolyte balance, unlike betamethasone which minimizes such effects.
C: Fludrocortisone is specifically designed for potent mineralocorticoid activity, making it unsuitable in this context where negligible effect is required.
D: Cortisol has notable mineralocorticoid effects, impacting sodium and water retention, thus does not meet the criteria for negligible impact.
Aldosterone enhances Na+ reabsorption in renal tubules by
Rationale:
Aldosterone enhances Na+ reabsorption in renal tubules by inducing the synthesis of Na+ K+ ATPase. This hormone increases the number of these pumps, facilitating sodium reabsorption and promoting water retention, thus regulating blood pressure and fluid balance effectively within the body.
A: Stimulating carbonic anhydrase does not directly relate to Na+ reabsorption and primarily influences bicarbonate and hydrogen ion balance in the kidneys, not sodium levels.
B: Inhibiting Na+ K+ ATPase would reduce sodium reabsorption, as this enzyme is essential for moving sodium out of the tubule cells, countering aldosterone’s action.
D: Promoting K+ secretion involves the expulsion of potassium ions, which is a separate process and does not contribute to sodium reabsorption, thus failing to address the question directly.
The insulin receptor is
Rationale:
The insulin receptor is a tyrosine protein kinase receptor. This type of receptor is characterized by its ability to autophosphorylate and activate signaling pathways involved in glucose uptake, metabolism, and cellular growth upon binding insulin.
B: G protein coupled receptor This classification does not apply, as G protein coupled receptors primarily interact with G proteins, which is distinct from the insulin receptor’s function and signaling mechanism.
C: Ion channel regulating receptor The insulin receptor does not function as an ion channel; rather, it activates intracellular signaling pathways, which is fundamentally different from ion channel regulation.
D: None of these This choice fails to recognize the established classification of the insulin receptor as a tyrosine protein kinase receptor, which is a well-documented aspect of its function.
A mass of adipose tissue that develops at the injection site is usually due to the patients neglect in rotating the insulin injection site. This is known as
Rationale:
Lipo hypertrophy
Lipohypertrophy occurs when fat accumulates in areas of repeated insulin injections due to the neglect of site rotation. This excess adipose tissue can lead to complications in insulin absorption and effectiveness.
A: Lipoatrophy Involves the loss of fat tissue, which contrasts with the accumulation seen in lipohypertrophy. This condition results in depressions rather than the buildup of adipose tissue.
B: Hypertrophic degenerative adiposity Refers to an increase in fat tissue due to degeneration, not specifically related to injection sites or the repeated use of insulin injections.
D: Atrophic skin lesion Describes a condition involving skin thinning or damage, which does not align with the buildup of fat tissue that lipohypertrophy exemplifies.
Metformin
Rationale:
Metformin does not cause hypoglycemia even in large doses. This characteristic makes it a unique and safe option for managing blood sugar levels in diabetic patients, as it primarily works by improving insulin sensitivity and reducing hepatic glucose production rather than stimulating insulin secretion.
B: Should not be combined with glipizide. Combining these medications can be beneficial in certain cases, as glipizide is an insulin secretagogue that complements metformin’s action.
C: Is contraindicated in obese NIDDM patients. In fact, metformin is often recommended for obese patients with non-insulin-dependent diabetes mellitus due to its effectiveness in weight management and glucose control.
D: Causes release of insulin from the pancreas. Unlike some diabetes medications, metformin does not directly stimulate insulin secretion from the pancreas, focusing instead on enhancing the body’s insulin sensitivity and glucose utilization.
Sulfonylureas are a primary mode of therapy in the treatment of
Rationale:
Sulfonylureas are a primary mode of therapy in the treatment of non-insulin-dependent (type 2) DM patients. These medications stimulate insulin secretion from pancreatic beta cells, effectively managing blood glucose levels in individuals with type 2 diabetes, where insulin resistance is prevalent.
A: Insulin-dependent (type 1) diabetes mellitus (IDDM) patients. Sulfonylureas are ineffective for IDDM patients, as their condition requires insulin therapy due to the absence of insulin production.
B: Diabetic patients experiencing severe hepatic or renal dysfunction. Patients with severe hepatic or renal dysfunction may face increased risk of sulfonylurea side effects, limiting their suitability as a treatment option.
C: Diabetic pregnant women. The use of sulfonylureas during pregnancy is not well established, as potential effects on fetal development raise concerns about their safety in this population.
The antidiabetic agent most likely to cause lactic acidosis is
Rationale:
B: Phenformin is the antidiabetic agent most likely to cause lactic acidosis due to its propensity to accumulate in the bloodstream, particularly in patients with renal impairment, leading to dangerous lactate buildup.
A: Chlorpropamide does not have a significant association with lactic acidosis; it primarily functions as a sulfonylurea, stimulating insulin secretion without the same risks as Phenformin.
C: Glipizide, another sulfonylurea, is unlikely to induce lactic acidosis as its mechanism centers on insulin release rather than affecting lactic acid metabolism or renal function.
D: Metformin is known to have a risk of lactic acidosis, but it is less than that of Phenformin, which has been withdrawn from the market due to this serious complication.
The most useful glucose test used in monitoring diabetes mellitus (DM) therapy is
Rationale:
Blood monitoring provides a direct measurement of glucose levels, enabling precise tracking of diabetes management. This method allows for timely adjustments in therapy, ensuring better control and reducing the risk of complications associated with diabetes mellitus.
A: Urine monitoring Detects glucose excretion but does not provide real-time data on blood sugar levels, making it less effective for ongoing diabetes management.
C: Renal function monitoring Focuses on kidney health rather than glucose levels, which does not directly assist in managing diabetes therapy effectively.
D: Cardiovascular monitoring Primarily assesses heart health, not glucose regulation, thus lacking relevance in the specific context of diabetes management.
Select the drug which tends to reverse insulin resistance by increasing cellular glucose transporters.
Rationale:
B: Troglitazone enhances cellular sensitivity to insulin by promoting the expression of glucose transporters on cell membranes. This mechanism effectively improves glucose uptake, thus reversing insulin resistance in affected tissues.
A: Glibenclamide stimulates insulin secretion from pancreatic beta cells, focusing on increasing insulin availability rather than enhancing glucose transporter functionality in peripheral tissues.
C: Acarbose acts as an alpha-glucosidase inhibitor, delaying carbohydrate absorption in the intestines instead of directly addressing insulin resistance or increasing glucose transporter expression.
D: Prednisolone, a corticosteroid, can actually induce insulin resistance due to its effects on glucose metabolism and fat distribution, which counteracts the goal of improving glucose transport.
In a patient of diabetes mellitus maintained on insulin therapy, administration of the following drug can vitiate glycaemia control.
Rationale:
Administration of Prednisolone can vitiate glycaemia control in a patient with diabetes mellitus on insulin therapy.
Prednisolone is a corticosteroid that can induce insulin resistance, leading to elevated blood glucose levels. This effect can significantly complicate glycaemic management, requiring adjustments in insulin dosages to maintain optimal blood sugar control, thus negatively impacting the patient's diabetes management.
B: Prazosin primarily treats hypertension and does not significantly affect glucose metabolism in diabetic patients, making it unlikely to disrupt glycaemic control.
C: Paracetamol is an analgesic and antipyretic medication that does not influence blood sugar levels, therefore maintaining the stability of glycaemia in diabetic patients.
D: Phenytoin is an anticonvulsant that may have some effect on glucose metabolism but does not have a direct, significant impact on glycaemic control in diabetic patients.
Guargum limits post-prandial glycaemia by
Rationale:
Guargum limits post-prandial glycaemia by slowing carbohydrate absorption from the intestine. This mechanism delays glucose entry into the bloodstream, which helps to moderate blood sugar spikes after meals, enhancing glycaemic control.
A: Inhibiting intestinal brush border α glucosidases does not pertain to guargum's action. This process involves different mechanisms that primarily affect carbohydrate breakdown rather than absorption rates within the intestine.
C: Releasing incretins from the intestine does not describe guargum's function. Incretins are hormones that enhance insulin secretion, but they are not directly influenced by guargum’s effects on carbohydrate absorption.
D: Promoting uptake of glucose into skeletal muscles is unrelated to guargum’s role. This action involves insulin response and muscle physiology rather than the absorption processes within the gastrointestinal tract.
The treatment of gestational diabetes would comprise of
Rationale:
D: Insulin. Insulin is the most appropriate treatment for gestational diabetes as it effectively lowers blood glucose levels without crossing the placenta, ensuring the safety of both mother and fetus.
A: Glibenclamide. This medication, while sometimes used in diabetes management, is not typically recommended for gestational diabetes due to potential risks to fetal development.
B: Chlorpropamide. This sulfonylurea is not advisable for gestational diabetes treatment, primarily due to its long half-life and the associated risks of causing hypoglycemia in both mother and infant.
C: Glipizide. Although effective for managing type 2 diabetes, glipizide poses risks when prescribed during pregnancy, including adverse effects on fetal health, making it unsuitable for gestational diabetes.
The sulfonylurea with a relatively longer duration of action is
Rationale:
A: Chlorpropamide offers a relatively longer duration of action among sulfonylureas, making it suitable for patients requiring extended glycemic control. Its pharmacokinetic profile allows for sustained insulin secretion stimulation, effectively managing blood glucose levels.
B: Tolbutamide has a shorter duration, requiring more frequent dosing, which limits its efficacy for prolonged glycemic management compared to longer-acting sulfonylureas like chlorpropamide.
C: Glibenclamide, while effective, does not have as extended a duration as chlorpropamide, resulting in less sustained insulin release and requiring careful monitoring of blood glucose levels.
D: Glipizide typically has a shorter duration of action, necessitating multiple doses throughout the day, which makes it less ideal for patients needing consistent insulin stimulation over time.
For increasing the excretion of weakly acidic drugs, urine should be made
Rationale:
Urine should be made alkaline.
Increasing urine pH reduces the protonation of weakly acidic drugs, enhancing their ionization and solubility, which promotes excretion. This method effectively increases the elimination of these drugs from the body, improving therapeutic outcomes and reducing toxicity risks.
B: At neutral pH. Neutral pH does not significantly influence the ionization of weakly acidic drugs, thus limiting their urinary excretion compared to an alkaline environment that promotes ionization.
C: Acidic. Acidic urine enhances the reabsorption of weakly acidic drugs due to increased protonation, thereby decreasing their solubility and reducing their excretion from the body.
D: pH does not affect the urinary excretion of acidic drugs. This statement overlooks the critical role of urine pH in affecting drug solubility and ionization, which are crucial for excretion efficiency.
Longest acting insulin is
Rationale:
D: Protamine zinc insulin is the longest acting insulin. Its formulation allows for a prolonged duration of action, making it suitable for less frequent dosing and better overall glycemic control in patients requiring insulin therapy.
A: Insulin zinc suspension has a shorter duration of action compared to protamine zinc insulin, making it less effective for patients needing a prolonged insulin effect for blood sugar management.
B: Isophane insulin, while long-acting, does not provide the extended duration of action offered by protamine zinc insulin, leading to more frequent administration requirements for optimal glycemic control.
C: Globin zinc insulin is less commonly used and has a shorter action profile than protamine zinc insulin, limiting its efficacy in maintaining stable blood glucose levels over extended periods.
Which of the following is true of acarbose?
Rationale:
Acarbose limits postprandial hyperglycaemia in diabetes. This drug functions by inhibiting enzymes that digest carbohydrates, thereby slowing glucose absorption after meals and effectively stabilizing blood sugar levels in diabetic patients.
A: It reduces absorption of glucose from intestines. While acarbose does slow carbohydrate digestion, its primary effect is on postprandial glucose levels rather than directly reducing overall glucose absorption.
B: It produces hypoglycaemia in normal as well as diabetic subjects. Acarbose does not typically induce hypoglycaemia; it works primarily by moderating blood sugar levels after meals, not by lowering them excessively.
D: It raises circulating insulin levels. Acarbose does not elevate insulin levels; its mechanism primarily focuses on delaying carbohydrate absorption and managing glucose levels, rather than influencing insulin secretion directly.
Glucagon release from pancreas is stimulated by
Rationale:
Glucagon release from the pancreas is stimulated by adrenaline. Adrenaline, particularly during stress or low glucose levels, enhances glucagon secretion to elevate blood glucose by promoting glycogenolysis and gluconeogenesis in the liver.
A: High blood glucose level. Elevated glucose levels signal the pancreas to release insulin, not glucagon, as the body works to lower excess glucose in the bloodstream.
B: Insulin. Insulin is primarily responsible for lowering blood glucose levels and promoting glucose uptake, directly opposing the actions of glucagon, which aims to increase glucose levels.
C: Somatostatin. Somatostatin functions to inhibit hormone secretion, including glucagon, thereby regulating the overall balance of insulin and glucagon rather than stimulating glucagon release.
Diuretic effective in diabetes insipidus is
Rationale:
Thiazides are effective in diabetes insipidus. Their mechanism reduces urine output by enhancing sodium and water reabsorption in the distal convoluted tubule, which is beneficial for managing the condition and minimizing excessive urination.
B: Loop diuretic Loop diuretics primarily act on the ascending loop of Henle, leading to significant diuresis, which exacerbates fluid loss rather than addressing the underlying issue in diabetes insipidus.
C: Mercurial diuretic Mercurial diuretics have historically been used for hypertension and edema, but they do not provide the targeted reabsorption benefits needed to effectively manage diabetes insipidus.
D: Carbonic anhydrase inhibitor While carbonic anhydrase inhibitors affect bicarbonate reabsorption, they do not significantly reduce urine output, making them unsuitable for treating diabetes insipidus effectively.
Insulin
Rationale:
Insulin promotes synthesis of triglycerides. This hormone facilitates the conversion of glucose and fatty acids into triglycerides, which are then stored in adipose tissues, contributing to energy storage and regulation in the body.
A: Release is enhanced by somatostatin. Somatostatin primarily inhibits insulin secretion, counteracting its effects, and thus does not enhance its release from the pancreas.
B: Has an identical chemical structure in all the species. Insulin varies among species; for instance, pig insulin differs slightly from human insulin, affecting its biological activity and therapeutic uses.
C: Release from the pancreas occurs only in the postprandial state. Insulin is also secreted during fasting and other situations, such as stress, not exclusively after meals.
The hypoglycaemic action of sulfonylureas is likely to be attenuated by the concurrent use of
Rationale:
Sulfonylureas' hypoglycaemic effect may be diminished by hydrochlorothiazide. This diuretic can induce hyperglycemia by promoting insulin resistance and affecting glucose metabolism, thereby counteracting the glucose-lowering actions of sulfonylureas.
B: Propranolol This beta-blocker does not significantly influence the glucose-lowering effects of sulfonylureas, as it primarily affects heart rate and blood pressure rather than glucose metabolism directly.
C: Chloramphenicol This antibiotic has minimal impact on glucose regulation and does not interact significantly with sulfonylureas, maintaining their hypoglycaemic efficacy during concurrent administration.
D: Aspirin While aspirin can influence various metabolic pathways, it does not substantially modify the hypoglycaemic response of sulfonylureas, allowing these medications to retain their intended effects on blood glucose levels.
Which of the following statements concerning insulin replacement therapy is most accurate?
Rationale:
Counting or regulating carbohydrate consumption is a necessity for all diabetic patients. Managing carbohydrate intake is crucial for optimal blood glucose control, as it directly influences insulin requirements and overall diabetes management.
A: Most commercial insulin products vary little with respect to time, course, and duration of hypoglycemic activity. Variation in insulin products exists, as different formulations can have distinct onset, peak, and duration profiles.
B: Regular insulins cannot be mixed with NPH (isophane insulin suspension). Regular insulin can indeed be mixed with NPH, allowing for combined therapy to achieve desired glycemic control.
C: Regular insulin cannot be given intravenously. In clinical practice, regular insulin is often administered intravenously for rapid and precise glucose management in various medical scenarios.