**Question:** Mast cell stabilizer used in Bronchial Asthma is

A. Cromolyn
B. Nedocromil
C. Nafamostat mesilate
D. Calcium channel blockers

**Core Concept:** Mast cells are essential immune cells that release histamine and other mediators upon activation, contributing to bronchoconstriction and inflammation in asthma. Mast cell stabilizers aim to prevent this release, thereby acting as anti-asthma medications.

**Why the Correct Answer is Right:** Among the provided options, Cromolyn (Ipratropium bromide) is a mast cell stabilizer that inhibits the release of histamine and other mediators from mast cells. It works by blocking calcium influx into mast cells, preventing the fusion of secretory vesicles with the cell membrane and reducing mediator release.

**Why Each Wrong Option is Incorrect:**

A. Nedocromil: Although a mast cell stabilizer, Nedocromil is less effective than Cromolyn in blocking calcium influx and reducing mediator release from mast cells.

B. Nafamostat mesilate: A serine protease inhibitor used for thrombosis prophylaxis and therapy, not indicated for asthma treatment.

C. Calcium channel blockers: These drugs (e.g., Verapamil, Nicorandil) are primarily used for cardiovascular conditions, not for asthma treatment.

**Clinical Pearl:** Cromolyn sodium (Intal) is a long-acting, non-sedating, and non-invasive therapy for asthma prevention and control. It is typically administered as a nebulized solution prior to exercise or exposure to allergens to reduce bronchoconstriction and asthma symptoms.

**Correct Answer:** Cromolyn (Ipratropium bromide) is the correct answer as it is a potent mast cell stabilizer and inhibits histamine release, providing effective asthma treatment.