Phenobarbital

(Redirected from Phenobarbitol)

General

  • Type: Anticonvulsant, barbiturate, barbituates
  • Dosage Forms
    • 65mg/mL injection
    • 20mg/5 mL oral solution
    • 15, 16.2, 30, 32.4, 60, 64.8, 97.2, 100mg tab

Adult Dosing

  • Status epilepticus
    • 20mg/kg, infuse at 50-100mg/min
    • May repeat once after 10 minutes with additional 5-10mg/kg
  • Alcohol withdrawal / Delirium Tremens
    • 130-260mg IV q15-20 min [1]
  • Seizures, maintenance dose
    • 50-100mg bid-tid

Pediatric Dosing

  • Status epilepticus
    • 20mg/kg over 10 minutes. May repeat full dose in 15 minutes
  • Seizures, maintenance dose
    • ≤5 yo: 3-5mg/kg/day in 1-2 divided doses
    • Children > 5 yrs: 2-3mg/kg/day in 1-2 divided doses
    • Adolescents: 1-3mg/kg/day in 1-2 divided doses

Special Populations

  • Pregnancy Rating: D
  • Lactation: Enters breast milk, use caution
  • Renal Dosing
    • Adult
      • GFR < 10, give every 12-16 hours
      • HD: Given before HD and 50% dose after HD
    • Pediatric: GFR < 10, decrease dose by 50% and give every 24 hours
  • Hepatic Dosing: Reduced dose recommended, but no defined protocols

Contraindications

  • Allergy to class/drug
  • Marked hepatic impairment
  • Porphyria

Adverse Reactions

Serious

  • Hypotension
  • Respiratory depression, apnea
  • Significant soft tissue injury with subcutaneous or intra-arterial administration
  • Agranulocytosis

Common

  • Sedation, respiratory depression

Pharmacology

  • Onset: Oral 20-60 min, IV 5 min
  • Peak: IV 30 min
  • Half-life: Neonates 45-500 hr, Infants 20-133 hr, Children 37-73 hr, Adults 53-140 hr
  • Metabolism: Hepatic
  • Excretion: Urine
  • Mechanism of Action: Barbituates

See Also

References

  • Lexicomp, UpToDate
  1. Rosenson J, Clements C, Simon B, Vieaux J, Graffman S, Vahidnia F, Cisse B, Lam J, Alter H: Phenobarbital for acute alcohol withdrawal: a prospective randomized double-blind placebo-controlled study. J Emerg Med. 2013 Mar;44(3):592-598.e2. Epub 2012 Sep 19.