What role does ephedrine serve in treating allergic rhinitis?

Ephedrine is effective in treating allergic rhinitis primarily because it functions as a decongestant. It works by stimulating alpha-adrenergic receptors, which leads to vasoconstriction in the nasal passages. This action reduces swelling and congestion, allowing for easier breathing and relief from the symptoms associated with allergic rhinitis.

In contrast to other options, ephedrine does not act as a leukotriene modifier, mast cell stabilizer, or antihistamine. Leukotriene modifiers work by blocking the action of leukotrienes, chemicals that contribute to inflammation in allergic reactions. Mast cell stabilizers prevent the release of histamine and other inflammatory substances from mast cells, while antihistamines specifically block the effects of histamine itself. These mechanisms are different from how ephedrine alleviates symptoms of nasal congestion, emphasizing its distinctive role as a decongestant in the management of allergic rhinitis.