prochlorperazine

Brand: Compazine

Beers Criteria Prototype: haloperidol
Drug Class: antiemetic / antipsychotic
Drug Family: antipsychotic
Subclass: phenothiazine D2 receptor antagonist
Organ Systems: gastrointestinalcns

Mechanism of Action

Phenothiazine with central D2 antagonism in CTZ (anti-emetic); also alpha-1, histamine H1, and muscarinic blockade.

dopamine D2 receptor

Indications

  • nausea/vomiting
  • migraine headache (acute — adjunct)
  • vertigo

Contraindications

  • CNS depression
  • Parkinson's disease
  • bone marrow suppression
  • children under 2 years

Adverse Effects

Common

  • drowsiness
  • EPS
  • hypotension
  • anticholinergic effects

Serious

  • tardive dyskinesia
  • NMS
  • QT prolongation

Pharmacokinetics (ADME)

Absorption ~13% oral bioavailability; IM preferred
Distribution moderate
Metabolism extensive hepatic
Excretion renal/fecal
Half-life 6-8 hours
Onset 30-40 min
Peak 1-2 hours (IM)
Duration 4-6 hours
Protein Binding >99%
Vd large

Drug Interactions

Drug / Agent Mechanism Severity
CNS depressants additive CNS depression major
phenothiazines additive toxicity major

Nursing Considerations

  1. Monitor for EPS; akathisia is common side effect
  2. IM or rectal suppository when oral not tolerated
  3. NMS: stop drug immediately if hyperthermia, rigidity, altered consciousness, autonomic instability develop
  4. Avoid in Parkinson's disease

Clinical Pearls

  • Acute dystonia: tongue protrusion, oculogyric crisis — treat with diphenhydramine or benztropine
  • IV administration increases EPS risk — IM preferred for parenteral use

Safety Profile

Pregnancy avoid
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required

Concordance Terms

Cross-referenced clinical concepts — click any term to see all content where it appears.