A 40-year-old man with generalised anxiety disorder refuses benzodiazepines because of past alcohol misuse. He is prescribed a drug that is a partial agonist at a specific serotonin receptor, has no sedative or muscle-relaxant properties, and takes about 2 weeks to act. That receptor is:
- A 5-HT2A
- B 5-HT1A ✓
- C 5-HT3
- D 5-HT4
Correct answer: B. 5-HT1A
Explanation
Buspirone is a partial agonist at presynaptic 5-HT1A autoreceptors. It relieves generalised anxiety without causing sedation, cognitive impairment, muscle relaxation or respiratory depression, has no cross-tolerance or physical dependence with benzodiazepines, and its full anxiolytic effect appears only after 1 to 2 weeks, unlike the immediate effect of benzodiazepines. The other serotonin receptor subtypes listed mediate hallucination, emesis and gut motility effects respectively.
Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.