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phenibut

N06BX22

Forms & Strengths

Oral powder (bulk)
Capsules 250 mg
Tablets 250 mg

Adult Dosing

Anxiety, asthenia: 250-500 mg orally 3 times daily for 2-3 weeks; may increase up to 750 mg 3 times daily if needed
Alcohol withdrawal support: 250-500 mg 3 times daily with gradual taper over 1-2 weeks
Maximum daily dose: 2500 mg

Pediatric Dosing

Safety and efficacy not established in pediatric patients (<18 years)
Not recommended for use in children due to high risk of toxicity and withdrawal

Indications

Anxiety and tension relief
Asthenic and depressive conditions
Sleep disorders and insomnia
Prevention of vestibular disorders and motion sickness
Alcohol withdrawal syndrome adjunct

Mechanism of Action

GABA-beta-phenyl derivative acting as a GABAB receptor agonist
Weak agonist at GABAA receptors at higher concentrations
Stimulates dopamine release and exhibits slight phenyl-ethylamine structure-related stimulant effects
Crosses the blood-brain barrier readily

Contraindications

Hypersensitivity to phenibut
Acute kidney injury or severe renal impairment
Severe hepatic impairment
Gastric ulcer or erosive gastrointestinal disease
Pregnancy and lactation

Adverse Reactions

Drowsiness, sedation, and fatigue
Nausea and gastric discomfort
Dizziness and headache
Irritability and paradoxical anxiety with chronic use
Severe withdrawal syndrome upon abrupt cessation (anxiety, insomnia, psychosis, tremors)

Drug Interactions

Central nervous system depressants (alcohol, barbiturates, benzodiazepines, opioids) resulting in enhanced sedation and respiratory depression
Antiepileptic drugs (potentiates anticonvulsant effects)
Antiparkinsonian agents
Neuroleptics and antipsychotics

Curated Content: Needs Vetting Before Put to Clinical Use