Section 19 · Monograph

Prochlorperazine

Reviewed Nov 2026FDA label

CompazinePhenothiazine antiemetic

Forms: Tab: 5, 10mg | Supp: 25mg | Inj: 5mg/mL
Dose: Nausea: 5-10mg PO every 6-8h, or 25mg PR every 12h; avoid in Parkinson's disease
MOA: D2 blockade at the chemoreceptor trigger zone

Black Box Warning

Increased mortality in elderly patients with dementia-related psychosis: elderly patients with dementia-related psychosis treated with antipsychotic drugs (both conventional and atypical) are at increased risk of death (~1.6-1.7x placebo in pooled trials), predominantly from cardiovascular or infectious causes
Prochlorperazine is not approved for the treatment of patients with dementia-related psychosis

Control of severe nausea and vomiting in adultsFDA-labeled
Management of schizophreniaFDA-labeled
Short-term treatment of generalized non-psychotic anxiety (oral formulation; maximum 20 mg/day, not to exceed 12 weeks)FDA-labeled

Piperazine phenothiazine derivative; primary antiemetic effect mediated by dopamine D2-receptor antagonism at the chemoreceptor trigger zone (area postrema)
Central antipsychotic effect via mesolimbic dopamine D2 receptor blockade
Additional antagonism at alpha-adrenergic, histaminergic, and muscarinic receptors contributes to sedation, orthostatic hypotension, and anticholinergic effects

Adult IM (nausea/vomiting): 5-10 mg, may repeat every 3-4 hours as needed; maximum 40 mg/day
Adult IV (nausea/vomiting): 2.5-10 mg by slow IV injection at a rate not exceeding 5 mg/min; maximum single dose 10 mg, maximum 40 mg/day
Adult oral (nausea/vomiting): 5-10 mg 3-4 times daily; maximum 40 mg/day
Adult rectal (suppository): 25 mg twice daily
Perioperative prophylaxis: 5-10 mg IM 1-2 hours before induction of anesthesia, or IV 15-30 minutes before induction (may repeat once in 30 minutes)

Pediatric (≥2 years, ≥20 lbs): approximately 0.06 mg/lb (0.13 mg/kg) IM; weight-based oral/rectal dosing per label, not to exceed adult maximums

Known hypersensitivity to phenothiazines
Comatose states or presence of large amounts of CNS depressants (alcohol, barbiturates, opioids)
Pediatric surgery
Children under 2 years of age or under 20 lbs (9 kg)
Pediatric use where dosage has not been established for the specific condition

CNS depressants (opioids, barbiturates, alcohol, benzodiazepines): additive sedation and respiratory depression
Reduces effectiveness of oral anticoagulants
Thiazide diuretics: may worsen orthostatic hypotension
Guanethidine and related antihypertensives: antihypertensive effect may be reduced or reversed
Propranolol: mutually increased plasma concentrations of both drugs
May alter phenytoin metabolism
Additive risk with other drugs that lower seizure threshold or prolong the QT interval

Drowsiness and sedation
Dizziness and orthostatic hypotension
Extrapyramidal symptoms (akathisia, acute dystonia, parkinsonism)
Tardive dyskinesia (may be irreversible; risk increases with cumulative dose/duration)
Neuroleptic malignant syndrome (rare, potentially fatal)
Blurred vision
Skin reactions/photosensitivity
Amenorrhea and other effects of hyperprolactinemia
Leukopenia, agranulocytosis (rare)
Cholestatic jaundice
Cardiac arrhythmias/QT prolongation

Complete blood count in patients with history of leukopenia/agranulocytosis or unexplained infection
Signs/symptoms of neuroleptic malignant syndrome (hyperthermia, muscle rigidity, altered mental status, autonomic instability)
Ongoing assessment for tardive dyskinesia and other extrapyramidal symptoms
Blood pressure/orthostatic vitals, particularly in elderly or volume-depleted patients
Liver function tests if fever occurs with signs of hepatic dysfunction
ECG in patients with risk factors for QT prolongation

Pregnancy: use only if potential benefit justifies potential risk to the fetus; neonates exposed during the third trimester are at risk for extrapyramidal and/or withdrawal symptoms following delivery
Lactation: phenothiazines are excreted in breast milk; exercise caution and weigh risks/benefits when used in nursing mothers