Pharm

Prochlorperazine

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Prochlorperazine, Compazine

  • See Also
  • Mechanism
  1. Phenothiazine Antiemetic
  2. Dopamine 2 Antagonist
    1. Active at the ChemoreceptorTrigger Zone in the Medulla of the Brainstem
    2. Similar to other Dopamine antagonist Antipsychotic agents
  • Adverse effects
  1. Orthostatic Hypotension (esp. IV dosing)
  2. Arrhythmia
  3. Sedation
  4. Constipation
  5. Dry Mouth
  6. Leukopenia
  7. Thrombocytopenia
  8. Hyperprolactinemia
  9. Extrapyramidal Reaction
    1. Precaution
      1. Reactions may be delayed up to 2 weeks after dose
      2. Slow injection over minutes reduces risk of Dystonic Reaction
    2. Reactions
      1. Akathisia (25-60% after single dose)
      2. Dystonic Reaction (4% after a single dose)
      3. Olsen (2000) Am J Emerg Med 18(5): 609-11 +PMID:10999579 [PubMed]
      4. Drotts (1999) Ann Emerg Med 34(4 Pt 1): 469-75 [PubMed]
    3. Concurrent Diphenhydramine (Benadryl) prevents Akathisia (NNT 5, ARR 22%)
      1. Diphenhydramine (Benadryl) 50 mg IV (adults) was the dose used in study
      2. Vinson (2001) Ann Emerg Med 37(2):125-31 +PMID:11174228 [PubMed]
  1. Adults
    1. Prochlorperazine 5-10 mg orally every 6 to 8 hours
    2. Prochlorperazine 5-10 mg IM or slow IV over 2 minutes every 3 to 4 hours as needed
    3. Prochlorperazine suppository 25 mg PR every 12 hours
    4. Sustained release Prochlorperazine 15 mg orally each morning or 10 mg orally twice daily
    5. Maximum PO/IV/IM/day: 40 mg
  2. Children (over age 2 years and >10 kg)
    1. Avoid IV dosing in children
    2. Prochlorperazine 0.1 mg/kg/dose PO/PR every 6-8 hours
    3. Prochlorperazine 0.1 to 0.15 mg IM q6-8 hours
  1. Give 10 mg IM or slow IV over 2 minutes, or 25 mg PR for single dose
  • Precautions
  1. Pregnancy Category C
  2. Unknown Safety in Lactation
  3. IV dosing must be administered over 2 minutes or more
  4. Lowers Seizure threshold
  • References
  1. Johnson (1993) Harriet Lane, Mosby, p. 521
  2. Hamilton (2020) Tarascon Pocket Pharmacopoeia
  3. Olsen (2000) Am J Emerg Med 18(5):609-11 [PubMed]
  4. Vinson (2001) Ann Emerg Med 37(2):125-31 [PubMed]