Which drug classification includes Tofranil, Marplan, Nardil?

• A. Antihistamine
• B. Antibiotic
• C. Antidepressant
• D. Antacid

Answer: (C)

The main idea here is recognizing drug classes by how they work. Tofranil, Marplan, and Nardil are all antidepressants. Tofranil (imipramine) is a tricyclic antidepressant that increases brain levels of mood-related chemicals by blocking their reuptake. Marplan (isocarboxazid) and Nardil (phenelzine) are monoamine oxidase inhibitors, which raise monoamine levels by preventing their breakdown. Because all three are used to treat depression through altering monoamine neurotransmission, they belong to the antidepressant class. The other options don’t fit: antihistamines treat allergy symptoms, antibiotics treat infections, and antacids neutralize stomach acid.