While administering an adrenergic aerosol bronchodilator treatment to an adult female patient, you notice an increase in her pulse rate from 81 beats/min to 125 beats/min after two minutes. Which of the following actions should you take?
Rationale:
Stop the treatment and notify the physician.
This action prioritizes patient safety by immediately halting the bronchodilator, which is causing a significant tachycardic response, and ensures timely medical evaluation. Rapid heart rate increases can indicate adverse effects or complications requiring professional assessment, preventing potential cardiac distress or other serious outcomes from continuing the aerosol therapy without intervention.
A: Use half of the standard dosage next time Underestimating the severity of the current reaction neglects urgent intervention; dosage reduction alone does not address the immediate risk posed by the elevated heart rate.
B: Add more diluent to the nebulizer chamber Diluting the medication does not rapidly reverse the tachycardic effect already occurring and does not respond to the acute safety concern present in this scenario.
C: Temporarily stop the treatment until the patient's heart rate decreases Pausing without notifying a physician overlooks the necessity for professional assessment and could delay critical medical intervention for the patient’s adverse cardiovascular response.
The physician has ordered acetylcysteine for a COPD patient with a large amount of secretions. Upon assessment, you noticed that the patient has an inadequate cough. Which of the following would you recommend?
Rationale:
Nasotracheal suctioning after treatment is recommended for a COPD patient with inadequate cough to effectively remove loosened secretions.
This option ensures that secretions mobilized by acetylcysteine are promptly cleared, preventing airway obstruction and respiratory complications. It compensates for the patient’s ineffective cough by providing direct airway clearance, which is crucial in managing mucus retention and maintaining airway patency in COPD patients with impaired cough reflexes.
A: Perform a bronchoalveolar lavage Invasive lavage is unnecessary initially and carries higher risk; it is not the first-line intervention for secretion clearance in COPD patients with inadequate cough.
C: Postpone therapy until the patient can cough effectively Delaying mucolytic treatment can worsen secretion retention and respiratory status; immediate intervention to clear secretions is critical regardless of cough ability.
D: Give dornase alpha instead of acetylcysteine Dornase alpha targets DNA in cystic fibrosis mucus, not COPD secretions; acetylcysteine is more appropriate for COPD mucus viscosity reduction.
An elderly man, in obvious respiratory distress due to exacerbation of his emphysema and chronic bronchitis, presents in the emergency department. One drug ordered by the physician, to be administered by respiratory therapist, is $N$-acetylcysteine. Which of the following is main action or purpose of this drug?
Rationale:
$N$-acetylcysteine primarily thins airway mucus secretions for easier removal by suctioning or postural drainage. It acts as a mucolytic by breaking disulfide bonds in mucus, reducing its viscosity and facilitating clearance, especially useful in respiratory conditions like emphysema and chronic bronchitis where thick secretions impair breathing and airway patency.
A: Block receptors for the cysteinyl leukotrienes does not describe $N$-acetylcysteine’s mechanism, which targets mucus properties rather than leukotriene pathways involved in inflammation and bronchoconstriction.
B: Inhibit metabolic inactivation of epinephrine or $B_2$-agonists that were administered refers to enzyme inhibition affecting drug metabolism, unrelated to the mucolytic actions of $N$-acetylcysteine.
C: Inhibit leukotriene synthesis focuses on anti-inflammatory effects not characteristic of $N$-acetylcysteine, which primarily modifies mucus consistency rather than leukotriene production.
The following drug is a quick relief medication for acute bronchial asthma
Rationale:
Inhaled salbutamol is a quick relief medication for acute bronchial asthma. It acts rapidly as a short-acting beta-2 agonist, relaxing bronchial smooth muscles and providing immediate bronchodilation, which quickly relieves acute asthma symptoms and bronchospasm, making it ideal for emergency use during asthma attacks.
B: Montelukast is a leukotriene receptor antagonist used for long-term asthma control and prevention, not for immediate symptom relief during acute bronchial asthma attacks.
C: Nedocromil by inhalation prevents asthma symptoms by stabilizing mast cells and reducing inflammation but does not provide rapid bronchodilation required for acute asthma relief.
D: Oral theophylline has a slower onset of action and is primarily used for long-term asthma management, so it is unsuitable for quick relief during acute bronchial asthma episodes.
All the following are employed in inhalation therapy of asthma except
Rationale:
Dexamethasone is not employed in inhalation therapy of asthma. Beclomethasone, Budesonide, and Triamcinolone are inhaled corticosteroids commonly used to reduce airway inflammation in asthma management. Dexamethasone, although a corticosteroid, is primarily administered systemically and not via inhalation, making it unsuitable for targeted asthma inhalation therapy where localized lung delivery is crucial for efficacy and reduced systemic effects.
A: Beclomethasone is used as an inhaled corticosteroid in asthma to reduce airway inflammation and prevent exacerbations by delivering medication directly to the lungs, enhancing local efficacy with minimal systemic absorption.
B: Budesonide functions as an inhaled corticosteroid specifically formulated for asthma inhalation therapy, reducing airway inflammation and improving respiratory function through targeted delivery.
D: Triamcinolone is employed via inhalation in asthma treatment to decrease bronchial inflammation, providing effective local therapy that aids in controlling symptoms and limiting systemic side effects.
Erythromycin should not be given to patient being treated with terfenadine because
Rationale:
Erythromycin should not be given to a patient being treated with terfenadine because dangerous ventricular arrhythmias can occur.
This is due to erythromycin's inhibition of the cytochrome P450 3A4 enzyme, which leads to increased terfenadine levels, causing QT interval prolongation and potentially fatal cardiac arrhythmias like torsades de pointes, making their combination highly risky and contraindicated.
A: Erythromycin induces the metabolism of terfenadine suggests increased breakdown, but erythromycin actually inhibits metabolism, raising terfenadine levels dangerously.
C: Terfenadine inhibits metabolism of erythromycin is inaccurate; terfenadine does not affect erythromycin’s metabolic pathways or clearance.
D: Terfenadine antagonizes the antimicrobial action of erythromycin incorrectly implies reduced efficacy, whereas the interaction causes cardiac toxicity, not antimicrobial antagonism.
The 5-HT antagonist that has antihypertensive property is
Rationale:
Ketanserin is the 5-HT antagonist that has antihypertensive properties. It selectively blocks 5-HT2 receptors and alpha-1 adrenergic receptors, leading to vasodilation and lowered blood pressure. This dual action makes ketanserin effective in managing hypertension by reducing peripheral vascular resistance and improving blood flow, distinguishing it from other 5-HT antagonists lacking these combined effects.
A: Methysergide primarily prevents migraines by blocking serotonin receptors but does not significantly influence blood pressure regulation or possess antihypertensive effects, limiting its use to migraine prophylaxis rather than hypertension treatment.
B: Cyproheptadine acts mainly as an antihistamine and serotonin antagonist with appetite-stimulating properties, but it lacks the specific receptor profile or vascular effects necessary to lower blood pressure effectively.
D: Ondansetron is a 5-HT3 receptor antagonist used predominantly as an antiemetic; it does not block 5-HT2 receptors or alpha-1 adrenergic receptors, so it does not contribute to blood pressure reduction.
Toxicities of Hâ‚ antihistamines include which one of the following?
Rationale:
H1 antihistamines can cause P450 inhibition as a toxicity. This occurs because some H1 antihistamines interfere with cytochrome P450 enzymes, leading to altered metabolism of other drugs and potential drug interactions. Such enzyme inhibition can increase plasma concentrations of co-administered medications, raising the risk of adverse effects or toxicity, which is a significant clinical consideration when prescribing these agents.
A: Blurred vision relates more commonly to anticholinergic side effects, not primarily a toxicity of H1 antihistamines. This symptom is typically associated with other drug classes affecting ocular accommodation.
B: Diarrhea is not a recognized toxicity of H1 antihistamines; gastrointestinal disturbances usually manifest as dryness or constipation, rather than increased bowel movements.
C: Orthostatic hypotension is generally linked to alpha-adrenergic blockade or other antihypertensive agents, not a frequent or direct effect of H1 antihistamines.
An 11-year-old boy has just arrived in the ER with cystic fibrosis and a pulmonary infection. Upon assessment, you note very thick secretions. Which of the following drugs would you recommend for this patient?
Rationale:
Nebulized dornase alpha is recommended for this patient. Dornase alpha is a mucolytic enzyme that breaks down extracellular DNA in thick mucus, reducing viscosity and improving clearance in cystic fibrosis patients with pulmonary infections. It specifically targets the pathophysiology of cystic fibrosis secretions, enhancing lung function and decreasing infection risk without causing airway irritation or damage.
A: Nebulized acetylcysteine causes bronchospasm and airway irritation, making it unsuitable for cystic fibrosis patients with thick secretions. It is less effective and can exacerbate respiratory symptoms.
C: Nebulized 0.9% saline primarily hydrates secretions but does not enzymatically break down DNA, rendering it less effective in reducing mucus viscosity in cystic fibrosis lung infections.
D: Direct instillation of acetylcysteine is invasive and increases risk of airway damage and bronchospasm, making it inappropriate compared to safer nebulized administration routes.
Muscarinic agonists such as pilocarpine, and $B$ blockers, are among the drugs used to manage a case of glaucoma, they also share properties that are particularly relevant to patients with asthma. Which of the following statements summarizes best what that relevance is?
Rationale:
Muscarinic agonists and beta blockers are contraindicated or pose great risks for people with asthma.
These drugs can exacerbate asthma symptoms by causing bronchoconstriction or airway irritation, significantly increasing the risk of asthma attacks or respiratory distress, making them unsafe for asthmatic patients despite their use in glaucoma management.
B: Degranulate mast cells, cause bronchoconstriction Mast cell degranulation is primarily linked to allergic responses, not directly caused by muscarinic agonists or beta blockers.
C: Tend to raise intraocular pressure in patients who have both glaucoma and asthma These drugs typically lower intraocular pressure; they do not elevate it, even in patients with concurrent asthma.
D: Useful for acute asthma, not for ambulatory patients Neither muscarinic agonists nor beta blockers serve as treatments for acute asthma episodes or chronic ambulatory asthma management.
The physician ordered 2.5 mL ipratropium bromide TID for a 70-year-old female COPD patient with bronchospasm. Which of the following methods would you use in order to deliver this medication?
Rationale:
The medication should be delivered using a small volume nebulizer with a mouthpiece. This method ensures accurate dosing of 2.5 mL ipratropium bromide, optimizes drug deposition in the lungs, reduces medication loss, and enhances patient control during inhalation, which is crucial for effective treatment of bronchospasm in a COPD patient.
A: Dry powder inhaler lacks the capacity to deliver liquid medications like ipratropium bromide, making it unsuitable for this prescribed volume and formulation.
B: Ultrasonic nebulizers may degrade ipratropium bromide due to heat generation, and are generally not recommended for this drug’s stability and dosage requirements.
C: Small volume nebulizer with a mask can result in medication loss through exhalation and less precise dosing compared to the mouthpiece, reducing delivery efficiency.
The following agents if given to an asthmatic are likely to cause catastrophic bronchospasm:
Rationale:
Carvedilol is likely to cause catastrophic bronchospasm in asthmatic patients. Carvedilol is a non-selective beta-blocker that blocks beta-2 adrenergic receptors responsible for bronchodilation, leading to bronchoconstriction and severe bronchospasm. This effect is dangerous in asthmatics, as their airways are already hyperresponsive and prone to narrowing, making carvedilol a high-risk agent.
B: Losartan is an angiotensin II receptor blocker primarily affecting blood pressure regulation, without significant bronchoconstrictive effects, thus it does not provoke bronchospasm in asthmatic individuals.
C: Adenosine causes transient bronchospasm rarely in sensitive individuals but generally does not induce catastrophic bronchospasm, making it less hazardous than beta-blockers for asthmatics.
D: Lidocaine (lignocaine) is a local anesthetic with minimal impact on airway smooth muscle tone and does not typically trigger bronchospasm in asthma patients.
Theophylline produce a bronchodilator effect through:
Rationale:
Theophylline produces a bronchodilator effect by inhibiting the PDE enzyme.
This inhibition prevents the breakdown of cyclic AMP (cAMP), leading to increased cAMP levels in smooth muscle cells, causing relaxation and bronchodilation. The elevated cAMP activates protein kinase A, which reduces intracellular calcium, resulting in airway smooth muscle relaxation and improved airflow in conditions like asthma and COPD.
A: Stimulation of $B_2$-receptors involves direct receptor activation, which is characteristic of beta-agonists, not theophylline, whose mechanism is enzymatic inhibition rather than receptor binding.
B: Decreasing c-AMP levels would constrict airways since cAMP promotes relaxation; theophylline actually raises cAMP by blocking PDE, opposing this action.
C: Blockade of M1-receptors influences neural transmission but does not directly cause bronchodilation like PDE inhibition; theophylline's primary effect is enzymatic, not cholinergic receptor antagonism.
All of the following statements about anti-cough remedies are true, EXCEPT:
Rationale:
Cough suppressants are called antiemetics.
Cough suppressants are actually antitussives, not antiemetics, which are drugs used to prevent nausea and vomiting. Antitussives reduce the cough reflex, making option A incorrect. The other options correctly describe different aspects of cough treatment, such as suppressing dry cough, guaiacol's role, and codeine's side effects.
B: Dry irritative cough should be suppressed accurately reflects treatment to relieve discomfort and prevent tissue damage.
C: Guaiacol is a stimulant expectorant correctly identifies its role in loosening mucus and facilitating its removal.
D: Codeine can be complicated by constipation properly notes a common opioid side effect affecting bowel movements.
Treatment of status asthmaticus include all of the following, EXCEPT:
Rationale:
Treatment of status asthmaticus does not include aminophylline orally. Aminophylline is typically administered intravenously in severe asthma attacks due to its unpredictable absorption and delayed onset when taken orally, making it unsuitable for emergency management in status asthmaticus where rapid action is crucial.
A: Adequate hydration supports mucus clearance and prevents dehydration, which is essential during severe asthma exacerbations, making it a standard supportive care component.
B: Salbutamol by nebulizer provides rapid bronchodilation, critical for relieving airway obstruction in status asthmaticus, thus it is an appropriate treatment.
D: Hydrocortisone I.V reduces airway inflammation swiftly, indispensable for controlling severe asthma attacks and preventing progression, confirming its role in status asthmaticus management.
Bacteria that make either a fermentative or respiratory set of enzymes are known as
Rationale:
Bacteria that make either a fermentative or respiratory set of enzymes are known as facultative organisms. Facultative organisms possess metabolic flexibility, enabling them to switch between aerobic respiration and fermentation depending on oxygen availability. This adaptability allows survival in fluctuating environments by using oxygen when present and fermenting when oxygen is absent, demonstrating their dual enzymatic pathways and ecological versatility.
A: Obligate anaerobes strictly rely on anaerobic metabolism and cannot survive in oxygenated environments, lacking the enzymatic systems required for aerobic respiration or fermentation flexibility.
B: Obligate aerobes depend solely on oxygen for respiration, possessing enzymes exclusively for aerobic pathways, thus unable to ferment or switch metabolic processes under anaerobic conditions.
C: Microaerophiles require reduced oxygen levels for growth and have limited capacity for fermentation, primarily utilizing aerobic respiration enzymes adapted to low-oxygen environments rather than alternating enzyme systems.
The following should be administered to an otherwise healthy 27-year-old male with acute severe asthma:
Rationale:
Nebulized salbutamol should be administered to an otherwise healthy 27-year-old male with acute severe asthma. Nebulized salbutamol is a rapid-acting beta-2 agonist that relaxes bronchial smooth muscle, providing immediate bronchodilation and symptom relief. It is the first-line treatment for acute severe asthma, improving airflow and oxygenation effectively and safely in emergency situations, making it essential for initial management.
A: Intravenous midazolam primarily serves as a sedative or anxiolytic, lacking bronchodilatory effects necessary for acute asthma treatment, and may depress respiratory drive, worsening respiratory status instead of improving airway obstruction.
C: Intravenous glucocorticosteroids reduce airway inflammation but have a delayed onset, making them unsuitable as immediate relief agents for acute severe asthma episodes.
D: Nebulized salmeterol is a long-acting beta-2 agonist designed for maintenance therapy, not for rapid symptom relief in acute severe asthma attacks, thus inappropriate for emergency treatment.
You are called to administer aerosolized albuterol to a 38-year-old patient. Which of the following side effects would you expect to see?
Rationale:
Shaking and tremors are common side effects of aerosolized albuterol.
Albuterol is a beta-2 adrenergic agonist that relaxes bronchial smooth muscle but also stimulates beta receptors in skeletal muscle, causing tremors and shakiness. These symptoms arise due to peripheral nervous system stimulation. Such side effects are well-documented and usually mild, often resolving as the body adjusts to the medication.
A: Hypotension Low blood pressure is not typically induced by albuterol, which generally causes mild increases in heart rate and blood pressure rather than decreases, making hypotension unlikely during administration.
B: Bradycardia Slowing of the heart rate contradicts albuterol’s known effects, which usually include tachycardia or increased heart rate due to beta-adrenergic stimulation, thus bradycardia is not an expected side effect.
C: Bronchospasm Albuterol is a bronchodilator designed to relieve bronchospasm, so causing bronchospasm would be paradoxical and is not a recognized adverse reaction in normal therapeutic use.
In acute severe asthma hydrocortisone:
Rationale:
Hydrocortisone is usually given via the intravenous route in acute severe asthma. This method ensures rapid delivery and onset of action, crucial in emergencies. Intravenous administration bypasses gastrointestinal absorption delays, providing prompt anti-inflammatory effects essential for reversing airway obstruction. It is a standard practice supported by clinical guidelines for managing life-threatening asthma exacerbations efficiently and safely.
B: Subjective improvement from steroids typically takes longer than 30-60 minutes, as anti-inflammatory benefits require several hours to manifest, not just minutes. Immediate relief is mostly due to bronchodilators, not corticosteroids.
C: Hydrocortisone is not contraindicated in growing children; it is often used cautiously to manage severe asthma attacks. Its benefits outweigh risks when carefully monitored, especially during acute exacerbations.
D: Hydrocortisone is not contraindicated in pregnancy; it is considered relatively safe and frequently utilized to control severe asthma, protecting both maternal and fetal health during exacerbations.
A patient suffering status asthmatics presents in the emergency department. Even large parenteral doses of a selective $B_2$ agonist fail to dilate the airways adequately; rather, they cause dangerous degrees of tachycardia. Which of the following pharmacologic interventions or approaches is most likely to control the acute symptoms and restore the bronchodilator efficacy of the adrenergic drug?
Rationale:
Parenteral corticosteroids are most likely to control acute symptoms and restore bronchodilator efficacy by reducing airway inflammation and edema, which enhances responsiveness to $B_2$ agonists in status asthmaticus.
A: Add inhaled cromolyn lacks immediate efficacy in acute severe asthma and does not rapidly reverse bronchospasm or inflammation during status asthmaticus.
C: Give parenteral diphenhydramine provides antihistamine effects but does not address airway inflammation or improve beta-agonist responsiveness in acute severe asthma.
D: Switch to epinephrine may increase heart rate dangerously without improving beta-2 receptor responsiveness or reducing airway inflammation effectively in status asthmaticus.
Omalizumab:
Rationale:
Omalizumab is administered by subcutaneous injection. This monoclonal antibody targets IgE and is given as a subcutaneous injection to reduce allergic responses in moderate to severe asthma and chronic idiopathic urticaria. Its delivery method allows for gradual absorption and sustained therapeutic effects, distinguishing it from other administration routes used in allergy and asthma treatments.
A: Is contraindicated in patients with IgE-mediated sensitivity to inhaled allergen This choice is misleading because omalizumab specifically targets IgE to reduce allergic reactions and is not contraindicated due to IgE-mediated sensitivity; rather, it is designed to help such patients.
B: Is used to treat severe acute attacks Omalizumab is not appropriate for acute asthma exacerbations as it requires time to exert effects; acute attacks need immediate bronchodilators or corticosteroids instead.
D: Inhibits warfarin metabolism via CYP 2C9 There is no evidence that omalizumab interferes with warfarin metabolism or CYP enzymes; it functions by binding IgE and does not affect cytochrome P450 pathways.
Adverse effects associated with the use of theophylline include:
Rationale:
Cardiac dysrhythmias are adverse effects associated with theophylline use. Theophylline, a methylxanthine bronchodilator, has a narrow therapeutic index and stimulates the central nervous system and heart, potentially causing arrhythmias. These cardiac disturbances result from increased catecholamine release and direct cardiac muscle stimulation, making dysrhythmias a significant concern during theophylline therapy, especially at toxic levels.
B: Convulsions can occur with theophylline toxicity, but they are less common than cardiac dysrhythmias and usually represent severe overdose rather than typical adverse effects during therapeutic use.
C: Oral candidiasis is linked to inhaled corticosteroids rather than theophylline, as the drug does not promote fungal overgrowth in the oral cavity or impair local immunity.
D: Headache is a nonspecific symptom that may occur with many drugs, but it is not a characteristic or primary adverse effect associated specifically with theophylline treatment.
In asthmatics, mast cell degranulation on the cell surface could be inhibited by the following EXCEPT:
Rationale:
Mast cell degranulation on the cell surface in asthmatics could be inhibited by all the listed drugs except Pindolol.
Pindolol lacks significant mast cell stabilizing properties and primarily functions as a non-selective beta-blocker with intrinsic sympathomimetic activity, which can potentially worsen asthma symptoms by promoting bronchoconstriction rather than preventing mast cell degranulation.
A: Terbutaline Terbutaline is a beta-2 agonist that relaxes bronchial smooth muscle and indirectly inhibits mast cell degranulation, reducing asthma symptoms effectively.
B: Ketotifen Ketotifen acts as a mast cell stabilizer and antihistamine, directly preventing the release of inflammatory mediators from mast cells in asthmatic conditions.
C: Aminophylline Aminophylline is a phosphodiesterase inhibitor that increases cAMP, which stabilizes mast cells and reduces mediator release, thereby decreasing bronchoconstriction in asthma patients.
All of the following drugs can dilate the bronchi, EXCEPT:
Rationale:
Sodium cromoglycate does not dilate the bronchi. This drug acts primarily as a mast cell stabilizer, preventing the release of inflammatory mediators and thus reducing bronchospasm indirectly. It does not have direct bronchodilator effects, unlike the other options which actively relax bronchial smooth muscles to widen the airways and ease breathing in obstructive conditions.
A: Salbutamol directly stimulates beta-2 adrenergic receptors in bronchial muscles, causing relaxation and bronchodilation, making it effective for immediate airway widening in conditions like asthma and COPD.
B: Theophylline works by inhibiting phosphodiesterase, leading to increased cAMP and bronchodilation, thus directly relaxing bronchial smooth muscle and improving airflow.
C: Ipratropium blocks muscarinic receptors in the airways, preventing bronchoconstriction mediated by the parasympathetic nervous system, resulting in bronchodilation and relief from airway obstruction.
A 19-year-old male just arrived to the emergency room with bilateral expiratory wheezing. Which of the following treatments would you recommend?
Rationale:
Aerosolized bronchodilator is the recommended treatment for a patient presenting with bilateral expiratory wheezing. This medication rapidly relaxes bronchial smooth muscle, relieving airway obstruction common in conditions like asthma or bronchospasm. It provides prompt symptomatic relief by improving airflow, reducing wheezing, and enhancing oxygen exchange, making it the most appropriate initial intervention in this emergency scenario.
A: Aerosolized cromolyn sodium Cromolyn sodium acts as a mast cell stabilizer, used primarily for prophylaxis rather than acute relief, thus unsuitable for immediate wheezing treatment.
C: Aerosolized normal saline solution Normal saline nebulization mainly hydrates secretions and does not provide bronchodilation or immediate symptom relief in acute wheezing episodes.
D: IV furosemide (Lasix) Furosemide is a diuretic used for fluid overload and pulmonary edema, not indicated for bronchospasm or wheezing caused by airway constriction.
The symptoms of allergen-mediated asthma result from which of the following?
Rationale:
The symptoms of allergen-mediated asthma result from increased release of mediators from mast cells. This release triggers bronchoconstriction, mucus secretion, and inflammation in the airways, which are hallmark features of asthma. Mast cell mediators like histamine and leukotrienes cause airway hyperresponsiveness and swelling, leading to the characteristic symptoms such as wheezing, coughing, and shortness of breath.
B: Increased adrenergic responsiveness of the airways does not directly cause asthma symptoms; adrenergic stimulation typically promotes bronchodilation, which contrasts with the bronchoconstriction seen in allergen-mediated asthma. This option misrepresents the underlying mechanism.
C: Increased vascular permeability of bronchial tissue contributes to edema but is a secondary effect rather than the primary cause of asthma symptoms. The main driver is mediator release from mast cells, not just permeability changes.
D: Decreased calcium influx into the mast cell would reduce mediator release, diminishing asthma symptoms. This option contradicts the actual pathophysiology where calcium influx promotes mediator secretion, making it an invalid explanation.
Betaâ‚‚ agonists (e.g. salbutamol, terbutaline, salmeterol):
Rationale:
Beta₂ agonists relax bronchial smooth muscle. These drugs stimulate beta₂-adrenergic receptors in the airway smooth muscle, causing muscle relaxation and bronchodilation. This action relieves bronchospasm in conditions like asthma and COPD, improving airflow. Their primary therapeutic effect is to open narrowed airways, making breathing easier, which is why they are widely used as rapid-acting or long-acting bronchodilators in respiratory management.
B: Inhibit release of mast cell and other inflammatory mediators Beta₂ agonists mainly cause bronchodilation, not direct inhibition of inflammatory mediator release, which is primarily the role of corticosteroids or mast cell stabilizers.
C: Reduce heart rate Beta₂ agonists typically increase heart rate due to beta₁ receptor cross-activation or reflex tachycardia, instead of causing a reduction in heart rate.
D: Cause pulmonary vasoconstriction Beta₂ agonists induce vasodilation rather than vasoconstriction, as beta₂ receptor activation relaxes pulmonary vessels, improving blood flow rather than restricting it.
The following drugs can produce pulmonary fibrosis:
Rationale:
Bleomycin can produce pulmonary fibrosis. Bleomycin is a chemotherapeutic agent notorious for causing lung toxicity, particularly pulmonary fibrosis, due to its oxidative damage to alveolar cells and induction of inflammatory responses. This adverse effect is well-documented in oncology, making it a primary example of drug-induced pulmonary fibrosis among the listed options.
A: Methotrexate Methotrexate primarily causes liver toxicity and bone marrow suppression; although it can rarely affect lungs, pulmonary fibrosis is not a common or characteristic side effect associated with this drug.
C: Busulphan Busulphan is linked mainly to bone marrow suppression and seizures, with pulmonary fibrosis being an infrequent and less recognized consequence, making it a less definitive cause of pulmonary fibrosis.
D: Lisinopril Lisinopril, an ACE inhibitor, typically causes cough or angioedema, but it lacks a significant association with pulmonary fibrosis, thus not contributing to fibrotic lung disease in clinical practice.
Intransasal spray of budesonide is indicated in
Rationale:
Intransasal spray of budesonide is indicated in perennial vasomotor rhinitis. Budesonide, a corticosteroid, effectively reduces nasal mucosal inflammation and symptoms like congestion and rhinorrhea in perennial vasomotor rhinitis, which is characterized by year-round nasal symptoms triggered by non-allergic factors. This treatment is preferred for chronic management due to its anti-inflammatory properties and minimal systemic absorption, enhancing patient safety.
A: Common cold This condition is primarily viral, and budesonide sprays do not target viral pathogens or provide symptomatic relief for acute infections, thus lacking efficacy in treating the common cold.
B: Acute vasomotor rhinitis Acute episodes involve transient nasal symptoms often resolving spontaneously; budesonide’s anti-inflammatory effect is more suited for chronic, persistent rhinitis rather than short-term acute manifestations.
D: Epistaxis Epistaxis involves bleeding from the nasal mucosa, where budesonide’s anti-inflammatory action does not address bleeding control or mucosal repair, making it unsuitable for managing nosebleeds.
A drug administered by inhalation of powder as a prophylactic for asthma is
Rationale:
Disodium cromolyn is administered by inhalation of powder as a prophylactic for asthma. This drug stabilizes mast cells, preventing the release of histamine and other inflammatory mediators, thereby inhibiting asthma attacks before they occur. It is specifically designed for prophylactic use rather than immediate relief, making it suitable for long-term management through inhalation.
A: Ephedrine is primarily a bronchodilator used for immediate relief, not typically administered by inhalation of powder nor used as a prophylactic agent against asthma attacks.
C: Isoproterenol acts as a rapid bronchodilator, administered by inhalation but mainly for acute asthma symptoms, not for prophylactic treatment using powder inhalation.
D: Orcytriphylline is a methylxanthine derivative with bronchodilator properties but is usually taken orally or parenterally, not via powder inhalation for asthma prevention.
You are called to instruct an 8-year-old girl with asthma on how to use an albuterol metered dose inhaler. Which of the following can be done in order to increase the deposition of the bronchodilator?
Rationale:
Adding a spacer or holding chamber to the MDI increases bronchodilator deposition. This device slows down the medication particles, allowing more time for inhalation and reducing oropharyngeal deposition. It improves coordination between actuation and inhalation, which is crucial for an 8-year-old child, ensuring more medication reaches the lungs effectively for better asthma control.
B: Removing the mouthpiece from the MDI disrupts the delivery system, causing medication to disperse improperly and reducing lung deposition, thereby decreasing the effectiveness of the bronchodilator treatment.
C: Inhaling quickly causes medication particles to impact the throat rather than reaching the lungs, which diminishes drug delivery efficiency and may increase side effects, making rapid inhalation unsuitable.
D: Switching from an MDI to a DPI may not be appropriate for young children who lack the inspiratory flow required to activate the DPI, leading to suboptimal medication delivery.