Chlorpheniramine is best categorized as which type of drug?

Chlorpheniramine is best categorized as which type of drug?

• A. Antihistamine
• B. Antidepressant
• C. Alpha-2 agonist
• D. MAOI

Answer: (A)

Chlorpheniramine is best categorized as an antihistamine because its main action is blocking histamine at the H1 receptor. By occupying these receptors, it prevents histamine released during allergic reactions from causing symptoms like itching, sneezing, and runny nose. This mechanism is different from antidepressants, alpha-2 agonists, or monoamine oxidase inhibitors, which act on other targets in the nervous system. Because many first-generation antihistamines cross into the brain, chlorpheniramine can cause sedation and has anticholinergic effects in addition to relieving allergic symptoms.

Chlorpheniramine is best categorized as an antihistamine because its main action is blocking histamine at the H1 receptor. By occupying these receptors, it prevents histamine released during allergic reactions from causing symptoms like itching, sneezing, and runny nose. This mechanism is different from antidepressants, alpha-2 agonists, or monoamine oxidase inhibitors, which act on other targets in the nervous system. Because many first-generation antihistamines cross into the brain, chlorpheniramine can cause sedation and has anticholinergic effects in addition to relieving allergic symptoms.