Anti-asthmatic drugs – classification and mechanism MCQs With Answer

Anti-asthmatic drugs – classification and mechanism MCQs With Answer

Anti-asthmatic drugs encompass bronchodilators, anti-inflammatory agents, and biologics used to manage asthma. For B. Pharm students, understanding classification, receptor targets (beta-2, muscarinic, leukotriene), intracellular mechanisms (cAMP, PDE inhibition, glucocorticoid receptor-mediated gene regulation), pharmacokinetics, side effects and drug interactions is essential. Key drug classes include short- and long-acting beta-agonists, inhaled corticosteroids, anticholinergics, methylxanthines, leukotriene modifiers, mast cell stabilizers and monoclonal antibodies. This set of MCQs emphasizes mechanisms of action, clinical use, adverse effects and important pharmacy considerations to deepen mechanistic understanding and prepare for exams and practice. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which mechanism primarily explains how beta-2 agonists produce bronchodilation?

• Smooth muscle inhibition via muscarinic receptor blockade
• Increase in intracellular cAMP leading to relaxation of bronchial smooth muscle
• Inhibition of leukotriene synthesis
• Reduced cytokine gene transcription through glucocorticoid receptor activation

Correct Answer: Increase in intracellular cAMP leading to relaxation of bronchial smooth muscle

Q2. Which drug class acts mainly by inhibiting phosphodiesterase leading to increased intracellular cAMP?

• Inhaled corticosteroids
• Methylxanthines
• Leukotriene receptor antagonists
• Anti-IgE monoclonal antibodies

Correct Answer: Methylxanthines

Q3. Ipratropium bromide provides bronchodilation by which mechanism?

• Beta-2 receptor agonism
• Competitive antagonism of muscarinic receptors on bronchial smooth muscle
• Inhibition of 5-lipoxygenase
• Stabilization of mast cell membranes

Correct Answer: Competitive antagonism of muscarinic receptors on bronchial smooth muscle

Q4. Which inhaled corticosteroid mechanism is most responsible for long-term control of asthma?

• Immediate bronchodilation through cAMP elevation
• Suppression of inflammatory gene expression via glucocorticoid receptors
• Direct blockade of leukotriene receptors
• Inhibition of phosphodiesterase 4 in neutrophils

Correct Answer: Suppression of inflammatory gene expression via glucocorticoid receptors

Q5. Montelukast primarily targets which pathway?

• Beta-adrenergic receptor activation
• Leukotriene D4 receptor antagonism (CysLT1 receptor)
• Phosphodiesterase inhibition
• IgE neutralization

Correct Answer: Leukotriene D4 receptor antagonism (CysLT1 receptor)

Q6. Which adverse effect is most characteristic of systemic corticosteroid therapy?

• Hypokalemia and tremor
• Adrenal suppression and hyperglycemia
• Acute bronchospasm due to mast cell activation
• QT prolongation and torsades de pointes

Correct Answer: Adrenal suppression and hyperglycemia

Q7. Theophylline toxicity is commonly exacerbated by inhibitors of which CYP enzyme?

• CYP3A4
• CYP2D6
• CYP1A2
• CYP2C9

Correct Answer: CYP1A2

Q8. Omalizumab is an anti-asthmatic biologic that acts by which mechanism?

• Blocking IL-5 mediated eosinophil activation
• Binding circulating IgE and preventing IgE-FcεRI interaction
• Inhibiting leukotriene synthesis by blocking 5-lipoxygenase
• Antagonizing the beta-2 adrenergic receptor

Correct Answer: Binding circulating IgE and preventing IgE-FcεRI interaction

Q9. Which drug is a selective long-acting beta-2 agonist (LABA)?

• Salbutamol (albuterol)
• Salmeterol
• Propranolol
• Ipratropium

Correct Answer: Salmeterol

Q10. Cromolyn sodium prevents asthma symptoms mainly by which action?

• Direct bronchodilation via beta-2 agonism
• Stabilizing mast cell membranes to inhibit mediator release
• Blocking muscarinic receptors
• Antagonizing leukotriene receptors

Correct Answer: Stabilizing mast cell membranes to inhibit mediator release

Q11. Which statement about corticosteroid inhalation therapy is correct?

• Inhaled corticosteroids provide immediate bronchodilation within seconds
• They reduce airway hyperresponsiveness and inflammation with chronic use
• They are primarily metabolized by 5-lipoxygenase
• They increase leukotriene production

Correct Answer: They reduce airway hyperresponsiveness and inflammation with chronic use

Q12. Roflumilast, used in COPD, acts by which mechanism relevant to airway inflammation?

• PDE4 inhibition leading to increased intracellular cAMP
• Direct antagonism of beta-2 receptors
• Inhibition of glucocorticoid receptors
• Blocking histamine H1 receptors

Correct Answer: PDE4 inhibition leading to increased intracellular cAMP

Q13. Which agent is most appropriate as a rapid-relief rescue inhaler for acute bronchospasm?

• Salmeterol
• Formoterol
• Salbutamol (albuterol)
• Fluticasone propionate

Correct Answer: Salbutamol (albuterol)

Q14. Leukotriene modifiers are particularly useful in asthma patients with which feature?

• Predominant neutrophilic inflammation
• Exercise-induced bronchoconstriction and aspirin-exacerbated respiratory disease
• Immediate response to short-acting beta-agonists only
• Severe IgE-mediated anaphylaxis

Correct Answer: Exercise-induced bronchoconstriction and aspirin-exacerbated respiratory disease

Q15. Which side effect is commonly associated with inhaled anticholinergics like tiotropium?

• Hypokalemia and tremor
• Dry mouth and urinary retention
• Adrenal suppression
• Hyperglycemia

Correct Answer: Dry mouth and urinary retention

Q16. Which statement about beta-2 agonist tolerance (tachyphylaxis) is true?

• Tachyphylaxis never occurs with inhaled beta-2 agonists
• Chronic overuse can reduce bronchoprotective effect due to receptor desensitization
• Tachyphylaxis is prevented by combining with anticholinergics only
• It results from increased glucocorticoid receptor expression

Correct Answer: Chronic overuse can reduce bronchoprotective effect due to receptor desensitization

Q17. Which pharmacokinetic consideration is important when dispensing theophylline?

• Theophylline has a wide therapeutic index and requires no monitoring
• Clearance is reduced by smoking and CYP inducers
• Narrow therapeutic index requiring plasma concentration monitoring and interactions via CYP1A2
• It is excreted unchanged in urine and unaffected by liver disease

Correct Answer: Narrow therapeutic index requiring plasma concentration monitoring and interactions via CYP1A2

Q18. Which monoclonal antibody targets IL-5 and is used for severe eosinophilic asthma?

• Omalizumab
• Mepolizumab
• Rituximab
• Infliximab

Correct Answer: Mepolizumab

Q19. Which drug class directly blocks cysteinyl leukotriene receptors to reduce bronchoconstriction?

• Short-acting beta-2 agonists
• Leukotriene receptor antagonists (e.g., montelukast)
• Systemic glucocorticoids
• Mast cell stabilizers

Correct Answer: Leukotriene receptor antagonists (e.g., montelukast)

Q20. Which inhaled drug is most likely to cause oral candidiasis if mouth is not rinsed after use?

• Inhaled corticosteroids (e.g., fluticasone)
• Short-acting beta-2 agonists
• Anticholinergics
• Theophylline

Correct Answer: Inhaled corticosteroids (e.g., fluticasone)

Q21. Which drug combination is commonly recommended to improve control in moderate to severe asthma?

• Inhaled corticosteroid plus long-acting beta-2 agonist
• Theophylline plus short-acting beta-2 agonist as monotherapy
• Anticholinergic plus oral steroid as first-line
• Montelukast plus ketoconazole

Correct Answer: Inhaled corticosteroid plus long-acting beta-2 agonist

Q22. Which agent reduces mediator release from eosinophils and is effective in allergic asthma by binding IL-5 or its receptor?

• Montelukast
• Mepolizumab
• Salbutamol
• Cromolyn

Correct Answer: Mepolizumab

Q23. Which laboratory change may occur with high-dose systemic beta-2 agonist therapy?

• Hyperkalemia due to cell lysis
• Hypokalemia due to intracellular shift of potassium
• Marked leukopenia
• Elevated serum cortisol

Correct Answer: Hypokalemia due to intracellular shift of potassium

Q24. Which statement best describes montelukast pharmacology relevant to pharmacy practice?

• It is a leukotriene receptor antagonist taken orally and useful for aspirin-sensitive asthma
• It is an inhaled steroid with immediate bronchodilator effect
• It is a monoclonal antibody given IV to block IgE
• It is a methylxanthine requiring no monitoring

Correct Answer: It is a leukotriene receptor antagonist taken orally and useful for aspirin-sensitive asthma

Q25. Which drug is most appropriate for a patient with both COPD and cardiovascular arrhythmia risk, considering bronchodilator choice?

• High-dose systemic beta-2 agonists without monitoring
• Ipratropium or tiotropium as anticholinergic bronchodilators
• Oral theophylline as first-line due to safety
• Chronic use of high-dose LABA alone without corticosteroid

Correct Answer: Ipratropium or tiotropium as anticholinergic bronchodilators

Q26. Which mechanism explains why inhaled route is preferred for many anti-asthmatic drugs?

• It increases systemic side effects compared to oral route
• It delivers drug directly to airways, providing rapid effect and lower systemic exposure
• It guarantees 100% systemic bioavailability
• It prevents local airway deposition

Correct Answer: It delivers drug directly to airways, providing rapid effect and lower systemic exposure

Q27. Which drug is a 5-lipoxygenase inhibitor that reduces leukotriene synthesis?

• Zileuton
• Montelukast
• Salbutamol
• Fluticasone

Correct Answer: Zileuton

Q28. Which monitoring parameter is important for patients on long-term oral corticosteroids?

• Serial ECGs only
• Blood glucose, blood pressure, bone density and HPA axis function
• Urine ketones weekly
• Serum theophylline concentrations

Correct Answer: Blood glucose, blood pressure, bone density and HPA axis function

Q29. Which statement about formoterol differs from salmeterol and is clinically relevant?

• Formoterol has a faster onset of action suitable for both maintenance and some fast relief roles
• Formoterol is a muscarinic antagonist
• Formoterol is not a LABA and has only short-acting effects
• Formoterol causes adrenal suppression directly

Correct Answer: Formoterol has a faster onset of action suitable for both maintenance and some fast relief roles

Q30. Which pharmacological interaction increases theophylline levels and risk of toxicity?

• Co-administration with CYP1A2 inducers like rifampin
• Co-administration with CYP1A2 inhibitors like ciprofloxacin
• Smoking tobacco
• High carbohydrate diet only

Correct Answer: Co-administration with CYP1A2 inhibitors like ciprofloxacin

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com