Respiratory System Drugs — MCQs

Respiratory System Drugs Indian Medical PG Practice Questions and MCQs

Question 291: Which class of bronchodilators is considered the most effective for managing chronic obstructive pulmonary disease (COPD)?

A. Anticholinergic agents (Correct Answer)
B. Beta-adrenergic agents
C. Cholinergic agents
D. Alpha-adrenergic agents

Explanation: ***Anticholinergic agents*** - **Anticholinergic agents** (LAMAs), like tiotropium, are proven most effective for **COPD** management due to their sustained bronchodilation and ability to reduce exacerbations [1], [2]. - They work by blocking the action of **acetylcholine** on muscarinic receptors in the airways, preventing bronchoconstriction [1]. *Beta-adrenergic agents* - **Beta-adrenergic agents** (LABAs) are also effective bronchodilators in COPD, but anticholinergics show a more consistent benefit in reducing **exacerbations** and improving lung function in long-term studies [2]. - While essential for bronchodilation, they primarily target beta-2 receptors, leading to immediate but sometimes less sustained effects compared to **LAMAs**. [2] *Cholinergic agents* - **Cholinergic agents** are typically **bronchoconstrictors** as they stimulate muscarinic receptors, leading to airway smooth muscle contraction. - They are generally contraindicated in asthma and COPD due to their ability to worsen **airway narrowing**. *Alpha-adrenergic agents* - **Alpha-adrenergic agents** primarily affect blood vessels and have minimal direct bronchodilatory effects on the airways. - They are not used as primary bronchodilators for **COPD**; their use might be restricted to systemic effects like decongestion.

Question 292: Which of the following is an antiasthmatic?

A. Histamine
B. Salbutamol (Correct Answer)
C. Acetylcholine
D. Serotonin

Explanation: ***Salbutamol*** - Salbutamol is a **short-acting beta-2 adrenergic agonist** that causes **bronchodilation** by relaxing the smooth muscles of the airways, making it an effective antiasthmatic medication. - It is often used as a **reliever medication** for acute asthma symptoms due to its rapid onset of action. *Histamine* - Histamine is a **mediator of allergic reactions** and inflammation, causing **bronchoconstriction** and increased mucus production, which worsens asthma symptoms. - It works by binding to H1 receptors in the airways, contributing to the pathophysiology of asthma rather than treating it. *Acetylcholine* - Acetylcholine is a **neurotransmitter** that can cause **bronchoconstriction** by stimulating muscarinic receptors in the airway smooth muscle. - While it plays a role in regulating airway tone, it is not used as an antiasthmatic; rather, **anticholinergics** are sometimes used to block its effects. *Serotonin* - Serotonin (5-hydroxytryptamine, 5-HT) can have **bronchoconstrictive effects** in some individuals and contribute to airway hyperresponsiveness, but it is not a direct therapeutic target for asthma. - It is primarily known for its role in the central nervous system and the gastrointestinal tract, and is not classified as an antiasthmatic drug.

Question 293: Omalizumab is indicated for which of the following conditions?

A. Multiple myeloma
B. Psoriasis
C. Bronchial asthma (Correct Answer)
D. Rheumatoid arthritis

Explanation: ***Bronchial asthma*** - Omalizumab is an **anti-IgE antibody** that binds to circulating IgE, preventing it from binding to mast cells and basophils, thus reducing allergic reactions. - It is specifically approved for the treatment of **moderate to severe persistent asthma** in patients over 6 years old whose symptoms are inadequately controlled by inhaled corticosteroids. *Multiple myeloma* - Multiple myeloma is a **plasma cell malignancy** affecting bone marrow, for which omalizumab has no approved indication. - Treatment typically involves **chemotherapy**, proteasome inhibitors, immunomodulatory drugs, and stem cell transplantation. *Psoriasis* - Psoriasis is a **chronic inflammatory skin condition** primarily treated with agents targeting inflammatory pathways such as TNF-alpha, IL-17, or IL-23, not IgE. - Common psoriasis medications include **topical corticosteroids**, phototherapy, and systemic biologics like adalimumab or ustekinumab. *Rheumatoid arthritis* - Rheumatoid arthritis is an **autoimmune disease** causing chronic joint inflammation, primarily treated with DMARDs (disease-modifying antirheumatic drugs) and TNF inhibitors. - **IgE does not play a significant role** in the pathogenesis of rheumatoid arthritis, making omalizumab ineffective for this condition.

Question 294: In comparison to inhaled adrenergic agonists, the inhaled anticholinergics:

A. Are more effective in bronchial asthma
B. Produce a slower response in bronchial asthma (Correct Answer)
C. Produce little benefit in chronic obstructive lung disease
D. Are better suited for control of an acute attack of asthma.

Explanation: ***Produce a slower response in bronchial asthma*** - **Inhaled anticholinergics** (e.g., ipratropium, tiotropium) block **muscarinic receptors**, leading to bronchodilation, but their onset of action is generally **slower** (15-30 minutes) compared to the rapid action of **beta-2 adrenergic agonists** (5 minutes). - This slower response makes them less ideal for **acute asthma attacks** where immediate bronchodilation is critical. - Anticholinergics are used as **add-on therapy** in asthma management. *Are more effective in bronchial asthma* - **Inhaled beta-2 adrenergic agonists** (e.g., salbutamol, albuterol) are typically **more effective** and are the **first-line treatment** for acute bronchodilation in asthma due to their rapid onset and potent effect. - **Anticholinergics** are often considered **add-on therapy** for asthma, particularly for patients who have an inadequate response to beta-agonists. *Produce little benefit in chronic obstructive lung disease* - **Inhaled anticholinergics** (e.g., tiotropium, ipratropium) are considered **first-line agents** and provide **significant benefit** in improving lung function and reducing exacerbations in **chronic obstructive pulmonary disease (COPD)**. - Their efficacy in COPD is often **superior** to beta-agonists for long-term maintenance therapy due to the prominent role of cholinergic tone in COPD bronchoconstriction. *Are better suited for control of an acute attack of asthma* - **Short-acting inhaled beta-2 adrenergic agonists** are the **drug of choice** for the rapid relief of acute asthma symptoms due to their quick onset of action. - **Inhaled anticholinergics** like **ipratropium** have a slower onset and are generally used as **adjunctive therapy** or for patients unable to tolerate beta-agonists during acute exacerbations.

Question 295: Which interleukin is specifically targeted by the monoclonal antibody Reslizumab in the treatment of bronchial asthma?

A. Interleukin-2
B. Interleukin-3
C. Interleukin-4
D. Interleukin-5 (Correct Answer)

Explanation: ***Interleukin-5*** - **Reslizumab** is a humanized monoclonal antibody specifically designed to target and inhibit **interleukin-5 (IL-5)** [1]. - By blocking IL-5, Reslizumab reduces the production, survival, and activation of **eosinophils**, which are key inflammatory cells in a subset of severe asthma [1]. *Interleukin-2* - **Interleukin-2 (IL-2)** primarily plays a role in the proliferation and differentiation of **T lymphocytes**, and its blockade is typically associated with immunosuppression. - While important in immune responses, IL-2 is not the specific target of Reslizumab for treating eosinophilic asthma. *Interleukin-3* - **Interleukin-3 (IL-3)** is involved in the growth and differentiation of various **hematopoietic stem cells** and is less directly linked to the pathogenesis of eosinophilic asthma than IL-5. - Medications targeting IL-3 are not used in the treatment of asthma. *Interleukin-4* - **Interleukin-4 (IL-4)** is a crucial cytokine involved in **Th2 immune responses**, promoting IgE production and B-cell activation, but it is not directly targeted by Reslizumab [1]. - Another monoclonal antibody, **Dupilumab**, targets both IL-4 and IL-13 receptors in asthma treatment [1].

Question 296: Which of the following is not typically used for the immediate treatment of acute asthma?

A. Prednisolone
B. Ipratropium bromide
C. Salmeterol (Correct Answer)
D. Salbutamol

Explanation: ***Salmeterol*** - **Salmeterol** is a **long-acting beta-2 agonist (LABA)**, typically used for **maintenance therapy** in asthma to prevent symptoms, not for immediate relief of an acute attack. - Its **slow onset of action** makes it unsuitable for the rapid bronchodilation required during an acute asthma exacerbation. *Prednisolone* - **Prednisolone** is an **oral corticosteroid** used in acute asthma exacerbations to reduce inflammation and prevent relapse. - While it has a delayed onset of action, it is a crucial component of immediate management to control the underlying inflammation. *Salbutamol* - **Salbutamol** is a **short-acting beta-2 agonist (SABA)**, which is the **first-line treatment** for immediate relief of acute asthma symptoms. - It acts rapidly to **bronchodilate** the airways, improving airflow within minutes. *Ipratropium bromide* - **Ipratropium bromide** is a **short-acting muscarinic antagonist (SAMA)** that can be used in conjunction with SABAs for acute severe asthma. - It provides **additional bronchodilation** by blocking acetylcholine's effects on bronchial smooth muscle.

Practice by Chapter

Bronchodilators

Practice Questions

Corticosteroids in Respiratory Disorders

Practice Questions

Anti-inflammatory Respiratory Agents

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Mast Cell Stabilizers

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Leukotriene Modifiers

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Antitussives and Expectorants

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Nasal Decongestants

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Pulmonary Surfactants

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Drugs for Pulmonary Hypertension

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Oxygen Therapy

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