Question

What is the mechanism of action of sodium cromoglycate?

Options

• It blocks H1 receptors on cell surfaces

• It prevents the release of histamine from mast cells

• It stimulates the production of histamine-degrading enzymes

• It neutralizes histamine already released in the circulation

Answer 1

Sodium cromoglycate acts by preventing the release of histamine from mast cells. This drug is particularly effective in respiratory allergies because it stabilizes mast cell membranes and inhibits degranulation. Unlike antihistamines that block histamine after its release, sodium cromoglycate prevents histamine release in the first place, making it a preventive agent best used before allergen exposure. It is commonly used as an inhaled powder for asthma and allergic rhinitis.