This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti-Emetic, Subject name: Pharmacology
All are antiemetic except - 
Select and explain. 
A. Ondansetran, B. Metoclopramide, C. Chlorpromazine, D. Bismuth
D: Bismuth
Answer: D: Bismuth 
Explanation: Ans. is 'd' i.e., Bismuth Antiemetic drugsAnticholinergics - Hyoscine, Dicyclomine.Ht antihistaminics Promethazine, cyclizine, Cinnarizine, etc.Neuroleptics (D2 blockers) - Chlorpromazine, Haloperidol, Droperidole etc.Prokinetics drugs - Metoclopramide, Domperidone, cisapride, Mosapride, Tegaserod.5-HT3 antagonists - Ondansetron, Granisetron.Adjuvant antiemetics - Dexamethasone, BZDs, Cannabinoids, Clonidine & ephedrine.