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
[{'content': 'Drug given for metoclopramide induced dystonic reaction is: \nSelect and explain. \nA. Pheniramine, B. Promethazine, C. Chlorpromazine, D. Prochlorperazine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (B) Promethazine(Ref: KDT 8th/e p180)"Acute muscle dystonia caused by antiemetic-antipsychotic drugs is promptly relieved by parenteral promethazine or hydroxyzine" This is based on central anti-cholinergic action of the drugs.Promethazine is a first generation anti-histaminic which has maximum penetration of blood brain barrier and maximum anticholinergic activity.', 'role': 'assistant'}]