Which of the following is true regarding 5-HT derivatives: March 2009: (A) Cisapride is selective 5-HT4 antagonist, (B) Ondansetron is a 5-HT3 agonist, (C) Cyproheptadine is 5-HT2A agonist, (D) Sumatriptan action is agonistically 5-HT 1B/1D receptor mediated
Answer is D. Ans. D: Sumatriptan action is agonistically 5-HT 113/1D receptor mediated Cisapride and renzapride are selective 5-HT4 agonists. Ondansetron is a selective 5-HT3 antagonist which inhibits vomiting by blocking these receptors in brainstem as well as in gut wall. Cyproheptadine is 5-HT2A antagonist and has additional H1 antihistaminic, anticholinergic and sedative propeies. Sumatriptan and other triptan are selective 5-HT 113/1D agonists, constricts cerebral blood vessels and has emerged as the most effective treatment of acute migraine attacks.