Dystonic Drug Reaction


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Figure 1-1 Patient with dystonic drug reaction.


What To Do:


image Administer 1 to 2 mg of benztropine (Cogentin) or 25 to 50 mg of diphenhydramine (Benadryl) IV, and watch for improvement of the dystonia over the next 5 minutes. Usually, the medication begins to work within 2 minutes of intravenous administration, and the symptoms completely resolve within 15 minutes. This step is both therapeutic and diagnostic. Benztropine produces fewer side effects (mostly drowsiness) and may be slightly more effective, but diphenhydramine is more likely to be on hand in the ED or physician’s office. Benztropine may be given to children older than 3 years of age at the dose of 0.01 to 0.02 mg/kg IV, IM, or PO.


image Instruct the patient to discontinue use of the offending drug and arrange for follow-up if medications must be adjusted. If the culprit is long acting, prescribe benztropine 2 mg or diphenhydramine 25 mg PO q6h for 24 to 72 hours to prevent a relapse.


What Not To Do:


image Do not do any diagnostic workup when findings are typical. Administer benztropine or diphenhydramine first to see if symptoms completely resolve.


image Do not confuse dystonia with tetanus, seizures, stroke, hysteria, psychosis, meningitis, or dislocation of the mandible. None of these will resolve with IV benztropine or diphenhydramine.


image Do not persist with treatment if the response is questionable or there is no response. Continue with the workup to find another cause for the dystonia (e.g., tetanus, seizures, hypomagnesemia, hypocalcemia, alkalosis, muscle disease).


image Do not use IV diazepam first because it relaxes spasms resulting from other causes and thus leaves the diagnosis unclear.


Aug 11, 2016 | Posted by in EMERGENCY MEDICINE | Comments Off on Dystonic Drug Reaction

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