What is the first-line treatment for acute dystonia?

The first-line treatment for acute dystonia is benztropine or diphenhydramine. Acute dystonia, which is often a side effect of antipsychotic medications, presents as sustained muscle contractions, abnormal postures, or oculogyric crises. Anticholinergic medications like benztropine are effective in reversing the acute symptoms because they counteract the dopamine blockade that leads to the dystonic reactions. Diphenhydramine, an antihistamine with anticholinergic properties, can also be used effectively to provide rapid relief from these acute symptoms.

In contrast, clonazepam is primarily a benzodiazepine that treats anxiety and seizures and is not typically indicated for acute dystonia. Haloperidol, while an antipsychotic, could exacerbate the symptoms of dystonia by further blocking dopamine receptors. Carbamazepine, an anticonvulsant mood stabilizer, does not address acute dystonic reactions specifically and is used in different contexts, such as bipolar disorder or seizure disorders. Therefore, the choice of benztropine or diphenhydramine for treating acute dystonia is based on their ability to counter the effects of dopamine antagonism effectively.