- Categorized as a dietary supplement (and relatively unregulated in U.S.)
- Marketed to consumers in U.S. for anxiety, relaxation, and sleep
- Increased poison control related cases 2010-2019 (see MMWR reference below)
- Developed in Soviet Union in 1960s as an Anxiolytic and sleep aid
- Similar to Baclofen in structure and activity
- GABA Agonist (primarily GABA-B)
- Sedation
- Hypothermia
- Beta-Phenylethylamine Antagonist
- Anxiolysis
-
Dopamine increase
- Sedation
- Dystonic Reaction
- Onset: 2-4 hours after oral dose
- Half-Life: 5.3 Hours
- Urinary excretion: 65%
- Typical: 250 mg orally once to three times daily
- Toxicity (high dose or prolonged use)
- Agitated Delirium
- Seizures
- Respiratory depression
- Aspiration
- Agitated Withdrawal (prolonged use)
- Toxicity
- See Unknown Ingestion
- Altered Level of Consiousness
- Bedside Glucose
- Consider coningestion
- Acetaminophen Level
- Alcohol Level
- Urine Drug Screen
- May result in MethamphetamineFalse Positive
- Toxicity
- See Unknown Ingestion
- Consider Activated Charcoal if intake within 1 hour of ingestion (in alert patient)
- Supportive Care
- Endotracheal Intubation and sedation if unprotected airway
- Benzodiazepines for Agitation or withdrawal
- Phenobarbital or Baclofen may also be used for withdrawal symptoms
- Baclofen is a derivative of Phenibut
- Disposition
- May discharge home if asymptomatic at 4 hours after ingestion
- Phenibut (Wikipedia)
- Tomaszewski (2020) Crit Dec Emerg Med 34(1): 32
- Graves (2020) MMWR Morb Mortal Wkly Rep 69:1227-8 [PubMed]
- Winter (2001) CNS Drug Rev 7(4):471-81 [PubMed]