Respiratory System Drugs Practice Questions

Q: Bromhexine acts by:

Depolymerisation of mucopolysaccharides. **Explanation:** **Bromhexine** is a potent **mucolytic agent** derived from the alkaloid vasicine. Its primary mechanism of action involves the **depolymerisation of mucopolysaccharides** within the bronchial secretions. It stimulates the release of lysosomal enzymes that break down the network of glycoprotein fibers in sputum. This process reduces the viscosity (thickness) of the mucus, making it thinner and easier to expectorate (clear from the airways). Additionally, it increases the permeability of the blood-bronchial barrier, enhancing the penetration of certain antibiotics like Amoxicillin or Erythromycin into the sputum. **Analysis of Incorrect Options:** * **A. Central opioid agonism:** This is the mechanism for **antitussives** like Codeine and Pholcodine, which suppress the cough reflex in the medulla. * **B. Muscarine receptor antagonism:** This describes **anticholinergics** (e.g., Ipratropium bromide), which cause bronchodilation and reduce secretions but do not depolymerize mucus. * **D. MAO inhibitor:** These drugs (e.g., Selegiline) are used in psychiatry and Parkinson’s disease; they have no role in respiratory mucus clearance. **High-Yield Clinical Pearls for NEET-PG:** * **Ambroxol** is the active metabolite of Bromhexine and shares the same mechanism. * **Acetylcysteine**, another mucolytic, works differently by breaking **disulfide bonds** in mucoproteins. * Bromhexine is contraindicated in patients with **gastric ulcers** as it may disrupt the gastric mucosal barrier. * It is often used as an adjuvant in chronic bronchitis, emphysema, and bronchiectasis.

Q: Which drug is NOT used in the management of severe persistent asthma?

Oral corticosteroids. **Explanation:** The management of **Severe Persistent Asthma** (Step 4 and 5 of GINA guidelines) focuses on achieving control using high-dose inhaled therapies and add-on controllers. **Why Oral Corticosteroids (OCS) is the correct answer:** While OCS are used to manage **acute exacerbations** of asthma, they are **not** recommended for the routine, long-term management of severe persistent asthma if other options are available. Due to significant systemic side effects (Cushingoid features, osteoporosis, hyperglycemia), OCS are considered a "last resort" (Step 5) only when the patient remains uncontrolled despite high-dose ICS-LABA and biologics. In the context of standard maintenance therapy options listed, it is the least preferred long-term intervention. **Analysis of Incorrect Options:** * **Short-acting beta-2 agonist (SABA):** These (e.g., Salbutamol) are the "reliever" medications used across all stages of asthma for immediate symptom relief. * **Long-acting beta-2 agonist (LABA):** Drugs like Salmeterol or Formoterol are the preferred "add-on" therapy to inhaled steroids in persistent asthma to provide 12–24 hour bronchodilation. * **Inhaled high-dose steroids (ICS):** High-dose ICS (e.g., Fluticasone) is the cornerstone of maintenance therapy for severe persistent asthma to reduce airway inflammation. **High-Yield NEET-PG Pearls:** * **Drug of Choice (Acute Attack):** SABA (Inhaled Salbutamol). * **Drug of Choice (Prophylaxis/Maintenance):** Inhaled Corticosteroids (ICS). * **Black Box Warning:** LABAs should **never** be used as monotherapy in asthma (increased risk of asthma-related death); they must always be combined with an ICS. * **New GINA Update:** Low-dose ICS-Formoterol is now the preferred reliever (SMART therapy) across most stages to reduce exacerbation risk.

Q: Which of the following drugs have an anti-inflammatory action on the airways?

Fluticasone. **Explanation:** The management of bronchial asthma and COPD involves two main categories of drugs: **Controllers** (Anti-inflammatory) and **Relievers** (Bronchodilators). **Correct Answer: A. Fluticasone** Fluticasone is a potent **Inhaled Corticosteroid (ICS)**. Corticosteroids are the most effective anti-inflammatory agents for the airways. They work by inhibiting the recruitment of inflammatory cells (eosinophils, T-lymphocytes) and suppressing the synthesis of pro-inflammatory cytokines (IL-4, IL-5). Note: While **C. Budesonide** is also an ICS and possesses anti-inflammatory properties, in single-choice questions, Fluticasone is often prioritized due to its higher topical potency and lower systemic bioavailability. **Analysis of Incorrect Options:** * **B. Ipratropium bromide:** This is a **Short-Acting Muscarinic Antagonist (SAMA)**. It acts as a bronchodilator by blocking M3 receptors on bronchial smooth muscle, reducing vagal tone. It has no significant anti-inflammatory action. * **D. Terbutaline:** This is a **Short-Acting Beta-2 Agonist (SABA)**. It provides rapid symptomatic relief by increasing intracellular cAMP, leading to bronchodilation, but it does not treat the underlying airway inflammation. **High-Yield NEET-PG Pearls:** * **Mechanism of Action:** Steroids act via cytoplasmic receptors to alter gene transcription (transactivation of anti-inflammatory genes and transrepression of pro-inflammatory genes like NF-κB). * **Side Effects:** The most common local side effects of ICS are **Oropharyngeal Candidiasis** (prevented by using a spacer and rinsing the mouth) and **Dysphonia**. * **Drug of Choice:** ICS are the first-line maintenance therapy for persistent asthma. * **Ciclesonide:** A "prodrug" steroid activated only in the lungs by esterases, minimizing local side effects like hoarseness.

Q: What is true about inhaled nitric oxide?

Dilates pulmonary arteries.. **Explanation:** **Inhaled Nitric Oxide (iNO)** is a potent, selective pulmonary vasodilator. Its primary mechanism involves the activation of soluble guanylate cyclase, which increases intracellular **cyclic GMP (cGMP)**, leading to smooth muscle relaxation in the pulmonary vasculature. **Why Option B is correct:** When inhaled, nitric oxide reaches only the ventilated alveoli. It diffuses into the adjacent pulmonary capillaries, causing localized vasodilation. This improves **Ventilation-Perfusion (V/Q) matching** by redirecting blood flow to well-ventilated areas of the lung (the "Shunt-reduction" effect), thereby decreasing pulmonary artery pressure (PAP) and improving oxygenation. **Why other options are incorrect:** * **Option A & C:** iNO does **not** cause systemic vasodilation or systemic hypotension. This is because once nitric oxide enters the bloodstream, it is immediately and rapidly inactivated by binding to **hemoglobin**, forming methemoglobin. This extremely short half-life (seconds) ensures its effects are limited strictly to the pulmonary circulation. * **Option C (Part 2):** iNO *decreases* pulmonary artery pressure; it does not increase it. **High-Yield Clinical Pearls for NEET-PG:** * **Indications:** Persistent Pulmonary Hypertension of the Newborn (PPHN), ARDS (to improve oxygenation), and during cardiac surgery to manage right heart failure. * **Toxicity:** Monitor for **Methemoglobinemia** (keep levels <2%) and Nitrogen Dioxide ($NO_2$) formation, which is cytotoxic. * **Rebound Effect:** Abrupt withdrawal can cause "Rebound Pulmonary Hypertension." Always taper the dose gradually. * **Diagnostic Use:** Used in the cardiac catheterization lab to test for "Vasoreactivity" in patients with primary pulmonary hypertension.

Q: Which of the following drugs used for bronchial asthma can lead to hoarseness of voice?

Ciclesonide. **Explanation:** The correct answer is **Ciclesonide**. **1. Why Ciclesonide is correct:** Ciclesonide is an **Inhaled Corticosteroid (ICS)**. Local side effects of ICS occur due to the deposition of the drug in the oropharynx. The most common side effects include **oropharyngeal candidiasis (thrush)** and **dysphonia (hoarseness of voice)**. Hoarseness occurs because the steroid causes local myopathy of the laryngeal muscles (vocal cord adductor muscles). *Note:* Ciclesonide is a **prodrug** activated by esterases in the bronchial epithelium. While it is designed to minimize systemic side effects, it can still cause local irritation or hoarseness if not used with a spacer or if the mouth is not rinsed after inhalation. **2. Why the other options are incorrect:** * **A. Theophylline:** A methylxanthine (phosphodiesterase inhibitor). Its side effects are primarily systemic, such as GI upset, tachycardia, tremors, and seizures at toxic levels, but it does not cause hoarseness. * **C. Umeclidinium:** A Long-Acting Muscarinic Antagonist (LAMA). Common side effects include dry mouth, urinary retention, and blurred vision (anticholinergic effects), but not hoarseness. * **D. Zafirlukast:** A Leukotriene Receptor Antagonist (LTRA) administered orally. It is associated with Churg-Strauss syndrome and hepatotoxicity, but since it is not inhaled, it has no local effect on the larynx. **3. NEET-PG High-Yield Pearls:** * **Prevention:** To reduce the risk of hoarseness and oral thrush, patients should be advised to use a **spacer** and **rinse their mouth** with water after every ICS dose. * **Ciclesonide Advantage:** Because it is a prodrug activated in the lungs, it has a lower incidence of oropharyngeal candidiasis compared to Fluticasone or Beclomethasone. * **Drug of Choice:** ICS are the "Controller" drugs of choice for all steps of persistent asthma.

Q: Which of the following is not a recommended treatment for acute severe bronchial asthma?

Salmeterol. **Explanation:** The management of **acute severe asthma (Status Asthmaticus)** requires drugs with a rapid onset of action to reverse life-threatening bronchospasm immediately. **Why Salmeterol is the correct answer:** Salmeterol is a **Long-Acting Beta-2 Agonist (LABA)**. While it has high lipid solubility and a long duration of action (12+ hours), it has a **slow onset of action** (approx. 15–20 minutes). In an acute emergency, immediate bronchodilation is required; using a slow-acting drug like Salmeterol can delay critical treatment and lead to clinical deterioration. Therefore, LABAs are used for maintenance/prophylaxis, never for acute relief. **Analysis of incorrect options:** * **Salbutamol & Terbutaline:** These are **Short-Acting Beta-2 Agonists (SABA)**. They are the first-line "rescue" medications because they have a rapid onset (2–5 minutes) and effectively relax airway smooth muscle during an attack. * **Methylxanthines:** While no longer first-line due to a narrow therapeutic index, intravenous **Aminophylline** or **Theophylline** can be used as adjunctive therapy in refractory cases of acute severe asthma that do not respond to SABAs and corticosteroids. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice (DOC)** for acute asthma: Inhaled SABA (Salbutamol). * **Formoterol Paradox:** Unlike Salmeterol, Formoterol is a LABA with a **fast onset**, making it the only LABA recommended for both maintenance and reliever therapy (SMART therapy). * **Treatment components for Acute Severe Asthma:** Oxygen, high-dose SABA (nebulized), systemic corticosteroids (Hydrocortisone/Prednisolone), and Ipratropium bromide. * **Magnesium Sulfate (IV):** Used in severe cases not responding to initial nebulization.

Q: Which of the following is NOT a side effect of inhaled corticosteroids?

Hypoglycemia. **Explanation:** Inhaled Corticosteroids (ICS), such as Budesonide and Fluticasone, are the mainstay of chronic asthma management. While they are designed for local action, a small fraction undergoes systemic absorption via the lungs or the gastrointestinal tract (if swallowed). **Why Hypoglycemia is the correct answer:** Glucocorticoids are "diabetogenic" hormones. They stimulate gluconeogenesis and decrease peripheral glucose uptake, leading to **Hyperglycemia**, not hypoglycemia. Therefore, hypoglycemia is not a side effect of corticosteroid therapy. **Analysis of Incorrect Options:** * **Adrenal Suppression (A):** High doses of ICS can suppress the Hypothalamic-Pituitary-Adrenal (HPA) axis through negative feedback, leading to secondary adrenal insufficiency. * **Cataract (B) & Glaucoma:** Systemic absorption of steroids can lead to increased intraocular pressure and the formation of posterior subcapsular cataracts. * **Osteoporosis (C):** Steroids inhibit osteoblast activity and decrease calcium absorption, leading to decreased bone mineral density and increased fracture risk over long-term use. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Local Side Effect:** Oropharyngeal Candidiasis (Thrush) and Hoarseness of voice (Dysphonia). * **Prevention:** Patients should be advised to **rinse their mouth with water** after each use or use a **spacer** device to minimize local deposition. * **Growth:** In children, high-dose ICS may cause a temporary reduction in growth velocity, though final adult height is generally unaffected. * **Ciclesonide:** A "prodrug" activated only in the lungs by esterases, which significantly reduces the risk of local side effects like thrush.

Question 1

Bromhexine acts by:

Accepted Answer

Depolymerisation of mucopolysaccharides

Answer

Central opioid agonism

Answer

Muscarine receptor antagonism

Answer

MAO inhibitor

Question 2

Which drug is NOT used in the management of severe persistent asthma?

Accepted Answer

Oral corticosteroids

Answer

Short-acting beta-2 agonist

Answer

Long-acting beta-2 agonist

Answer

Inhaled high-dose steroids

Question 3

Which of the following drugs have an anti-inflammatory action on the airways?

Accepted Answer

Fluticasone

Answer

Ipratropium bromide

Answer

Budesonide

Answer

Terbutaline

Question 4

All of the following antihistamines can be used topically except?

Accepted Answer

Levocetirizine

Answer

Ketotifen

Answer

Olopatadine

Answer

Astemizole

Question 5

What is true about inhaled nitric oxide?

Accepted Answer

Dilates pulmonary arteries.

Answer

Causes generalized (systemic) vasodilation.

Answer

Causes hypotension and increases pulmonary artery pressure.

Answer

All of the above.

Question 6

Which of the following drugs used for bronchial asthma can lead to hoarseness of voice?

Accepted Answer

Ciclesonide

Answer

Theophylline

Answer

Umeclidinium

Answer

Zafirlukast

Question 7

Which of the following is not a recommended treatment for acute severe bronchial asthma?

Accepted Answer

Salmeterol

Answer

Salbutamol

Answer

Terbutaline

Answer

Methyl xanthine

Question 8

Which of the following is NOT a side effect of inhaled corticosteroids?

Accepted Answer

Hypoglycemia

Answer

Adrenal suppression

Answer

Cataract

Answer

Osteoporosis

Question 9

Which of the following statements regarding methylxanthines is true?

Accepted Answer

They block the receptor-mediated actions of adenosine.

Answer

They can enhance water and electrolyte excretion.

Answer

They can relax bronchial smooth muscles.

Answer

Long-term ingestion can produce tolerance and physical dependence.

Question 10

Which of the following is a directly acting cough suppressant?

Accepted Answer

Dextromethorphan

Answer

Bromhexine

Answer

Acetylcysteine

Answer

Carbetapentane

Respiratory System Drugs — MCQs

Respiratory System Drugs — MCQs

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