What is the first-line treatment for acute dystonia induced by antipsychotic drugs?

The first-line treatment for acute dystonia induced by antipsychotic drugs is diphenhydramine. This medication is an antihistamine that has anticholinergic properties, making it effective in alleviating the symptoms of acute dystonia, which often presents as muscle spasms, stiffness, and abnormal postures. By blocking central acetylcholine receptors, diphenhydramine helps to restore the balance between dopamine and acetylcholine in the brain, thereby alleviating the acute symptoms.

While benzotropine, another anticholinergic agent, can also be used for this condition, diphenhydramine is generally preferred for rapid relief in acute settings. Amantadine may be used for certain types of movement disorders but is not the first-line treatment for acute dystonia. Similarly, valbenazine is specifically used for tardive dyskinesia rather than acute dystonia. Thus, diphenhydramine stands out as the most effective and established choice for quickly managing acute dystonia due to antipsychotic medications.