JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B. Pharmacy III Year PHARMACOLOGY-III Previous Question Paper (February/March-2022 - R17)

Drugs used in the management of asthma are classified as follows: Bronchodilators (β2-agonists like salbutamol and salmeterol; Methylxanthines like theophylline; Anticholinergics like ipratropium bromide), Leukotriene antagonists (montelukast, zafirlukast), Mast cell stabilizers (sodium cromoglycate), Inhaled corticosteroids (beclomethasone, fluticasone), and Monoclonal antibodies (omalizumab).

Omalizumab is a recombinant humanized monoclonal antibody that selectively binds to human immunoglobulin E (IgE). By binding to free IgE in the blood and interstitial fluid, it prevents IgE from binding to its high-affinity receptor (FcεRI) on the surface of mast cells and basophils. This inhibition reduces the release of inflammatory mediators such as histamine, leukotrienes, and cytokines that trigger asthmatic symptoms. It is administered via subcutaneous injection and is specifically indicated for patients with moderate to severe persistent allergic asthma that is inadequately controlled by inhaled corticosteroids.

Anti-tussive agents are classified into: Centrally acting agents (Opioids: codeine, pholcodine; Non-opioids: noscapine, dextromethorphan) and Peripherally acting agents (Demulcents, Local anesthetics, and Emollients).

Peripherally acting agents work by suppressing the cough reflex at the source of irritation rather than acting on the cough center in the medulla. They include: 1) Demulcents: These are soothing agents like honey, syrup, or glycerin that form a protective coating over the pharyngeal mucosa, reducing the stimulation of sensory nerve endings. 2) Local anesthetics: Benzonatate acts by anesthetizing the stretch receptors located in the lungs and pleura, thereby interrupting the afferent pathway of the cough reflex. 3) Emollients/Hydrating agents: Steam inhalation or increased fluid intake helps to soothe the inflamed respiratory tract and reduce the viscosity of secretions, thereby decreasing the mechanical irritation that triggers coughing.