Prochlorperazine

Prochlorperazine (Compazine) is a first-generation phenothiazine that works primarily as a dopamine D2 receptor antagonist in the chemoreceptor trigger zone, making it effective for controlling severe nausea and vomiting from a variety of causes, as well as vertigo associated with vestibular disorders such as Meniere's disease. At higher doses it also has antipsychotic activity and has been used in the management of psychotic disorders and severe anxiety. It is typically dosed 3 to 4 times daily for nausea/vomiting, with lower doses used for outpatient management and higher doses reserved for more severe or inpatient cases. As with other phenothiazines, prochlorperazine carries a risk of extrapyramidal symptoms (dystonia, akathisia, parkinsonism), sedation, and orthostatic hypotension, and it is contraindicated in patients with severe CNS depression or comatose states. It should be used with caution in the elderly and is not approved for dementia-related psychosis due to an increased risk of mortality in that population.