Respiratory System Drugs Practice Questions

Q: What is the most common side effect of inhaled beclomethasone?

Oropharyngeal candidiasis. **Explanation:** **Inhaled Beclomethasone** is a potent inhaled corticosteroid (ICS) used for the long-term management of bronchial asthma [1]. **Why Oropharyngeal Candidiasis is correct:** The primary mechanism of ICS involves local immunosuppression in the oral cavity and pharynx. When the drug particles deposit on the oral mucosa, they inhibit local cell-mediated immunity, allowing the overgrowth of opportunistic fungi, most commonly *Candida albicans*. This presents clinically as "oral thrush" (white, scrapable patches). **Analysis of Incorrect Options:** * **A. Adrenal suppression:** While a known side effect of systemic steroids, it is rare with inhaled forms unless used in very high doses for prolonged periods, as ICS have low systemic bioavailability [1]. * **C. Bronchoconstriction:** ICS are used to reduce airway inflammation and prevent bronchoconstriction [2]. While rare "paradoxical bronchospasm" can occur with any inhaler due to additives, it is not the most common side effect. * **D. Hepatitis:** Corticosteroids are not typically hepatotoxic; in fact, systemic steroids are sometimes used to treat autoimmune hepatitis. **NEET-PG High-Yield Pearls:** 1. **Prevention:** To minimize the risk of candidiasis and **dysphonia** (hoarseness of voice), patients should be advised to **rinse their mouth with water and spit** after every use [1]. 2. **Spacer Devices:** Using a large-volume spacer reduces oropharyngeal deposition and increases lung delivery, further decreasing local side effects [1]. 3. **Ciclesonide:** This is a "prodrug" activated by esterases in the lungs; it has the lowest risk of oral candidiasis because it is not active while passing through the oropharynx [1].

Q: Which of the following is a long-acting bronchodilator?

Formoterol. ### Explanation **Correct Answer: D. Formoterol** **Mechanism and Classification:** Formoterol is a **Long-Acting Beta-2 Agonist (LABA)**. It works by stimulating $\beta_2$ receptors in the bronchial smooth muscle, leading to increased intracellular cAMP and subsequent bronchodilation. Unlike short-acting agents, LABAs have a long lipophilic side chain that binds to the "exosite" near the $\beta_2$ receptor, allowing for a prolonged duration of action (approximately 12 hours). Formoterol is unique because it has a **fast onset of action** (similar to Salbutamol) despite its long duration, making it suitable for both maintenance and "SMART" (Single Maintenance and Reliever Therapy) in asthma. **Analysis of Incorrect Options:** * **A. Salbutamol (Albuterol):** A Short-Acting Beta-2 Agonist (SABA). It is the drug of choice for acute asthma attacks due to its rapid onset, but its duration is only 4–6 hours. * **B. Terbutaline:** Another SABA similar to Salbutamol. It is used for quick relief of bronchospasm and is also used off-label as a tocolytic to delay preterm labor. * **C. Adrenaline (Epinephrine):** A non-selective $\alpha$ and $\beta$ agonist. While it causes potent bronchodilation, it is ultra-short-acting and carries significant cardiac side effects. It is the drug of choice for **Anaphylaxis**, not routine asthma management. **High-Yield NEET-PG Pearls:** * **LABAs vs. SABAs:** Salmeterol and Formoterol are LABAs (12 hrs); Indacaterol, Vilanterol, and Olodaterol are **Ultra-LABAs** (24 hrs). * **Black Box Warning:** LABAs should **never** be used as monotherapy in asthma (risk of asthma-related death); they must always be combined with an Inhaled Corticosteroid (ICS). * **Salmeterol vs. Formoterol:** Salmeterol has a slow onset; Formoterol has a rapid onset. * **Side Effects:** Muscle tremors (most common), tachycardia, and hypokalemia.

Q: Which new drug has been approved for the treatment of drug-resistant tuberculosis?

Bedaquiline. **Explanation:** **Bedaquiline** is the correct answer. It is a diarylquinoline and represents the first new class of anti-tuberculosis drugs approved by the FDA in over 40 years. Its unique mechanism of action involves the **inhibition of mycobacterial ATP synthase**, an enzyme essential for energy production in *Mycobacterium tuberculosis*. It is specifically indicated for Multi-Drug Resistant TB (MDR-TB) as part of combination therapy when other regimens are ineffective. **Analysis of Incorrect Options:** * **Ibalizumab:** A humanized monoclonal antibody used as an entry inhibitor for the treatment of multidrug-resistant **HIV-1** infection. It binds to domain 2 of the CD4 receptor. * **Bictegravir:** A potent **Integrase Strand Transfer Inhibitor (INSTI)** used in the treatment of HIV/AIDS, typically found in combination tablets (e.g., Biktarvy). * **Apalutamide:** A non-steroidal **anti-androgen** medication used primarily in the treatment of metastatic and non-metastatic castration-resistant prostate cancer. **High-Yield Clinical Pearls for NEET-PG:** * **Black Box Warning:** Bedaquiline can cause **QTc prolongation**; therefore, ECG monitoring is mandatory, especially when co-administered with other QT-prolonging drugs like Clofazimine or Moxifloxacin. * **Metabolism:** It is metabolized by the **CYP3A4** enzyme; hence, potent inducers like Rifampin should be avoided. * **WHO Guidelines:** Bedaquiline is now classified as a **Group A** drug (highly effective) in the treatment of MDR-TB, replacing older injectables like Kanamycin/Capreomycin. * **BPaL Regimen:** A modern, highly effective short-course regimen for XDR-TB consisting of **B**edaquiline, **P**retomanid, and **L**inezolid.

Q: Which of the following drugs is not used in the management of acute asthma?

Montelukast. **Explanation:** The management of **acute asthma** (status asthmaticus or acute exacerbation) requires drugs with a rapid onset of action to reverse bronchospasm and reduce airway inflammation immediately. **Why Montelukast is the correct answer:** Montelukast is a **Leukotriene Receptor Antagonist (LTRA)**. It works by blocking the CysLT1 receptor. While effective for the long-term prophylaxis of asthma and management of aspirin-induced asthma, it has a **slow onset of action** (taking hours to days for full effect). Therefore, it has no role in the emergency management of an acute attack where immediate bronchodilation is required. **Analysis of other options:** * **Salbutamol (Option A):** A Short-Acting Beta-2 Agonist (SABA). It is the **drug of choice** for acute asthma due to its rapid onset (2–5 minutes) in causing bronchodilation. * **Ipratropium (Option B):** A Short-Acting Muscarinic Antagonist (SAMA). It is used as an adjunct to SABAs in acute severe asthma to provide synergistic bronchodilation by blocking vagal-mediated bronchoconstriction. * **Hydrocortisone (Option D):** A systemic corticosteroid. It is administered intravenously in acute severe asthma to reduce airway inflammation and upregulate beta-receptors, preventing late-phase relapse. **High-Yield NEET-PG Pearls:** 1. **Drug of Choice for Acute Asthma:** Inhaled Salbutamol (SABA). 2. **Drug of Choice for Prophylaxis (Chronic Asthma):** Inhaled Corticosteroids (e.g., Fluticasone, Budesonide). 3. **Aspirin-Induced Asthma:** LTRAs like Montelukast are particularly effective here. 4. **Magnesium Sulfate:** Used intravenously in life-threatening asthma non-responsive to initial therapy.

Q: Vilanterol is FDA approved for the treatment of which condition?

COPD. **Explanation:** **Vilanterol** is an ultra-long-acting beta-2 agonist (uLABA) characterized by a rapid onset of action and a prolonged duration of effect (24 hours). 1. **Why COPD is correct:** Vilanterol is FDA-approved specifically for the maintenance treatment of airflow obstruction in patients with **Chronic Obstructive Pulmonary Disease (COPD)**, including chronic bronchitis and emphysema. It is typically used in fixed-dose combinations with long-acting muscarinic antagonists (LAMA) like Umeclidinium or inhaled corticosteroids (ICS) like Fluticasone furoate. 2. **Why Asthma is incorrect:** While Vilanterol is used in combination with Fluticasone furoate (Breo Ellipta) for asthma maintenance, **Vilanterol is NOT FDA-approved as a monotherapy for asthma.** In fact, the FDA maintains a "Black Box Warning" against using LABAs/uLABAs alone in asthma due to the increased risk of asthma-related death. In contrast, LABA monotherapy is acceptable and common in COPD management. 3. **Why "Both" is incorrect:** Because the question asks about the drug itself (Vilanterol), and its primary standalone indication and safety profile are rooted in COPD management, "COPD" is the most accurate answer for NEET-PG purposes. **High-Yield Clinical Pearls for NEET-PG:** * **Duration:** Vilanterol has a half-life that allows for **once-daily** dosing. * **Combinations:** * Vilanterol + Fluticasone furoate (ICS/LABA) * Vilanterol + Umeclidinium (LABA/LAMA) * Vilanterol + Umeclidinium + Fluticasone (Triple therapy - Trelegy Ellipta) * **Mechanism:** It works by increasing cyclic AMP, leading to relaxation of bronchial smooth muscle. * **Comparison:** Unlike Salmeterol (slow onset), Vilanterol has a **rapid onset** similar to Formoterol but lasts significantly longer.

Q: Which of the following drugs used in the management of bronchial asthma follows zero-order kinetics?

Theophylline. **Explanation:** **Theophylline** is the correct answer because it exhibits **capacity-limited elimination**, also known as **Zero-order kinetics**, at higher therapeutic or toxic concentrations. While most drugs follow first-order kinetics (where a constant fraction of the drug is eliminated per unit time), zero-order kinetics implies that a **constant amount** of the drug is eliminated regardless of its plasma concentration. This occurs because the metabolic enzymes in the liver become saturated. Consequently, even a small dose increase can lead to a disproportionate rise in plasma levels, increasing the risk of toxicity (narrow therapeutic index). **Analysis of Incorrect Options:** * **Salbutamol (A):** A short-acting beta-2 agonist (SABA) that follows first-order kinetics. It is primarily used as a rescue inhaler. * **Phenytoin (B):** While Phenytoin **does** follow zero-order kinetics (saturation kinetics), the question specifically asks for a drug used in the **management of bronchial asthma**. Phenytoin is an anti-epileptic. * **Tiotropium (C):** A long-acting muscarinic antagonist (LAMA) used in COPD and asthma that follows first-order kinetics. **NEET-PG High-Yield Pearls:** * **Mnemonic for Zero-Order Kinetics:** "**WATT P**a**S**" – **W**arfarin (at high doses), **A**lcohol (Ethanol), **T**heophylline, **T**olbutamide, **P**henytoin, and **S**alicylates (Aspirin). * Theophylline has a narrow therapeutic range (**10–20 µg/mL**). Toxicity manifests as severe vomiting, cardiac arrhythmias, and seizures. * In zero-order kinetics, the **half-life (t½) is not constant**; it increases as the plasma concentration increases.

Q: Which monoclonal antibody targets IL-5?

Mepolizumab. **Explanation:** **Mepolizumab** is a humanized monoclonal antibody that directly binds to and inhibits **Interleukin-5 (IL-5)** [1]. IL-5 is the primary cytokine responsible for the growth, differentiation, recruitment, and survival of eosinophils [1]. By neutralizing IL-5, Mepolizumab reduces eosinophilic inflammation, making it an effective "add-on" therapy for patients with severe eosinophilic asthma [1]. **Analysis of Incorrect Options:** * **Omalizumab:** This is a recombinant DNA-derived humanized IgG1 monoclonal antibody that binds selectively to **free IgE** in the blood and interstitial fluid [2]. It prevents IgE from binding to the high-affinity receptors (FcεRI) on mast cells and basophils, used primarily in severe allergic asthma [2]. * **Keliximab:** This is a monoclonal antibody that targets the **CD4 receptor** on T-lymphocytes. It was historically investigated for chronic asthma but is not a first-line treatment or a common IL-5 inhibitor. * **Altrakincept:** This is a recombinant soluble **IL-4 receptor** (not a monoclonal antibody). It acts as a decoy receptor to neutralize IL-4, thereby inhibiting the Th2 response. **High-Yield Clinical Pearls for NEET-PG:** * **IL-5 Antagonists:** Remember the "Mep-Res-Ben" trio: **Mepolizumab** and **Reslizumab** target the IL-5 ligand itself, while **Benralizumab** targets the IL-5 receptor (IL-5Rα). * **Indication:** These drugs are specifically used for **Severe Eosinophilic Asthma** (refractory to inhaled corticosteroids) [1]. * **Dupilumab:** Another high-yield drug that targets the **IL-4 receptor alpha subunit**, effectively blocking both IL-4 and IL-13 signaling.

Question 1

Which of the following statements about theophylline is TRUE?

Accepted Answer

Its use in asthma has declined because of a narrow safety margin.

Answer

Its dose needs to be reduced in smokers.

Answer

It acts by increasing the formation of cAMP.

Answer

Its plasma half-life is longer in children compared to adults.

Question 2

What is the most common side effect of inhaled beclomethasone?

Accepted Answer

Oropharyngeal candidiasis

Answer

Adrenal suppression

Answer

Bronchoconstriction

Answer

Hepatitis

Question 3

Which of the following is a long-acting bronchodilator?

Accepted Answer

Formoterol

Answer

Salbutamol

Answer

Terbutaline

Answer

Adrenaline

Question 4

Which new drug has been approved for the treatment of drug-resistant tuberculosis?

Accepted Answer

Bedaquiline

Answer

Ibalizumab

Answer

Bectegravir

Answer

Apalutamide

Question 5

What is the drug of choice for managing Hay fever?

Accepted Answer

Corticosteroids

Answer

First-generation antihistamines

Answer

Flibanserin

Answer

Second-generation antihistamines

Question 6

Systemic adverse effects of long-term inhaled corticosteroids are typically evident at daily doses exceeding which of the following thresholds?

Accepted Answer

600 mcg/day

Answer

200 mcg/day

Answer

400 mcg/day

Answer

800 mcg/day

Question 7

Which of the following drugs is not used in the management of acute asthma?

Accepted Answer

Montelukast

Answer

Salbutamol

Answer

Ipratropium

Answer

Hydrocortisone

Question 8

Vilanterol is FDA approved for the treatment of which condition?

Accepted Answer

COPD

Answer

Asthma

Answer

Both Asthma and COPD

Answer

None of the above

Question 9

Which of the following drugs used in the management of bronchial asthma follows zero-order kinetics?

Accepted Answer

Theophylline

Answer

Salbutamol

Answer

Phenytoin

Answer

Tiotropium

Question 10

Which monoclonal antibody targets IL-5?

Accepted Answer

Mepolizumab

Answer

Omalizumab

Answer

Keliximab

Answer

Altrakincept

Respiratory System Drugs — MCQs

Respiratory System Drugs — MCQs

On this page

Practice by Chapter

Want unlimited practice?