Final answer:
Haloperidol can cause extrapyramidal side effects due to its action on dopamine receptors in the brain, particularly in regions involved in motor control. Benadryl is used to treat these side effects. Risperidone, though similar, has a broader receptor antagonism profile, potentially offering fewer motor side effects.
Step-by-step explanation:
Haloperidol (Haldol) is an antipsychotic medication with a high risk of causing extrapyramidal side effects, such as dystonia, tardive dyskinesia, and muscular rigidity affecting the jaw, neck, or tongue. These effects are due to the drug's action on dopamine receptors in the brain, particularly in the motor control regions such as the basal ganglia and the extrapyramidal system. To manage these side effects, health professionals may monitor for early signs and administer intramuscular Benadryl (diphenhydramine) to counteract the reactions.
Risperidone (Risperdal), a newer antipsychotic introduced in 1994, also antagonizes dopamine D2 and serotonin type 2 receptors but has a reduced risk of extrapyramidal symptoms due to its additional blockade of adrenergic and histaminergic H1 receptors. Like other neuroleptic drugs, risperidone helps reduce agitation and psychotic symptoms over time, while largely preserving cognitive functions at ordinary doses.