Pentobarbital (Nembutal)


  • Sedatives


  • Hypnotic/sedative, anticonvulsant


  • Insomnia (short-term) status epilepticus

  • Facilitation of intubation and anesthesia


  • Respiratory depression

  • Severe liver impairment, porphyria


  • Pregnancy category D

  • Myasthenia gravis, myxedema, anemia, hepatic disease, renal disease

  • Hypertension, elderly, acute or chronic pain, mental depression

  • History of drug abuse, abrupt discontinuation, children

  • Hyperthyroidism, fever, diabetes

Adverse Reactions (Side Effects):

  • CNS: CNS depression, drowsiness, hangover, headache, lethargy, slurred speech, stimulation in elderly and children, physical dependence, mental depression

  • CV: bradycardia, hypotension

  • GI: constipation, diarrhea, nausea, vomiting

  • HEME: agranulocytosis, megaloblastic anemia, thrombocytopenia

  • RESP: apnea, bronchospasm, depression, laryngospasm

  • SKIN: abscess at injection site, angioedema, erythema multiforme, Stevens-Johnson syndrome, thromboplebitis, urticaria

  • MISC: rickets, osteomalacia


Administered orally, rectally, intramuscularly, intravenously

  • Adult:            

    • Hypnotic: 

      • PO 100-200mg at bedtime or 20mg 3-4 times daily for daytime sedation; IM 150-200mg

      • IV 100mg initially, may repeat every 1-3 minutes up to 200-500mg total

      • PR 120-200mg at bedtime

    • Preoperative sedation: 

      • IM 150-200mg

    • Pentobarbital coma for increased intracranial pressure: 

      • IV 10-15 mg/kg over 1-2 hours loading dose, then 1 mg/kg/hour 

      • INF, increase to 2-3 mg/kg/hour if necessary; maintain burst suppression on EEG

  • Child:            

    • Sedative: 

      • PO 2-6 mg/kg/day divided 3 times daily; max 100mg daily

    • Hypnotic: 

      • IM 2-6 mg/kg; max 100 mg/dose; PR <4years 3-6 mg/kg/dose, >4 years 1.5-3 mg/kg/dose

    • Preoperative sedation: 

      • PO/IM/PR 2-6 mg/kg; max 100 mg/dose

      • IV 1-3 mg/kg to max of 100mg until asleep

    • Pentobarbital coma for increased intracranial pressure: 

      • Same as adult

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