<prompt> Drug given for metoclopramide dystonic reaction is-PhenaraminePromethazineChlorphenaramineProchlorperazine  <response>: Ans. is b i.e., Promethazine o We all know, blockade of D2 receptors in brain produce extrapyramidal side effects as caused by antipsychotics, and acute muscular dystonia dystonic reaction is one of them. o Treatment of choice for acute muscular dystonia is central anticholinergic. o But, in given options, they have not given typical central anticholinergics. All options are typical antihistaminics. o As we also know that antihistaminics have anticholinergic propeies. So, amongst the given options we will have to choose the drug which has maximum central anticholinergic propey. First generation antihistaminics : i Have maximum anticholinergic propey ii Have maximum penetration of blood brain barrier For these two reasons, first generation antihistaminics have maximum central anticholinergic propey. o Amongst the given options, only promethazine is first generation antihistaminic. o Following statement of KDT will clear all doubts: Acute muscle dystonia caused by antiemetic-antipsychotic drugs is promptly relieved by parenteral promethazine or hydroxyzine. Remember o DOC for antipsychotic induced acute muscle dystonia central anticholinergic o If central anticholinergic is not given in the options -- antihistaminic with maximum central anticholinergic propey is the DOC. 