What medication should be co-administered with haloperidol to minimize the risk of extrapyramidal symptoms?

Co-administering diphenhydramine with haloperidol is a common practice to minimize the risk of extrapyramidal symptoms (EPS), which are side effects associated with the use of typical antipsychotics like haloperidol. Haloperidol, while effective for managing psychosis and schizophrenia, can block dopamine receptors in the brain, leading to movement disorders characterized by symptoms such as tremors, rigidity, and tardive dyskinesia.

Diphenhydramine is an antihistamine with anticholinergic properties that can effectively counteract the movement-related side effects caused by dopamine blockade. By administering diphenhydramine alongside haloperidol, clinicians can help mitigate these EPS, allowing for better patient tolerance of the antipsychotic treatment.

Other medications listed do not primarily serve the same purpose. For instance, chlorpromazine is also an antipsychotic and may not significantly reduce EPS risks; rather, it can contribute to similar side effects. Lorazepam may help with anxiety and agitation but does not specifically target the prevention of EPS. Olanzapine is an atypical antipsychotic and while it may have a different side effect profile, it does not serve to minimize EPS induced by haloperidol