Phenibut (4‐amino‐3‐phenyl‐butyric acid): Availability, prevalence of use, desired effects and acute toxicity

Abstract

Phenibut is readily available in the UK from Internet sites selling NPS. Its desired and adverse effects appear similar to other gamma-aminobutyric acid receptor agonists. [Owen DR, Wood DM, Archer JRH, Dargan PI. Phenibut (4-amino-3-phenyl-butyric acid): Availability, prevalence of use, desired effects and acute toxicity. Drug Alcohol Rev 2016;35:591-596].

Severe phenibut poisoning: An adolescent case cluster

“…). It was developed in the Soviet Union in the 1960s and is still used in some countries for the management of anxiety, insomnia and alcohol withdrawal . In Australia it is a prohibited substance and listed by the Therapeutic Goods Administration as a schedule 9 agent.…”

“…In Australia it is a prohibited substance and listed by the Therapeutic Goods Administration as a schedule 9 agent. Recently, it has gained prominence as a novel psychoactive substance, used for its cognition enhancing, euphoric and anxiolytic properties . It is readily available for purchase online from international websites.…”

“…Phenibut is primarily a GABA B agonist, but also has actions at GABA A and dopamine receptors as well as calcium channels . One volunteer study found a half‐life of 5.3 h, with 65% of the drug recovered unchanged in the urine .…”

“…One volunteer study found a half‐life of 5.3 h, with 65% of the drug recovered unchanged in the urine . Recreational users report the onset of effects within 2–4 h following oral administration, with peak effect by 6 h and a duration of 15–24 h . The toxic dose is poorly defined, but toxicity has been reported following only 1000 mg .…”

Dissociative Intoxication and Prolonged Withdrawal Associated With Phenibut

“…Psychosis, hallucinations, insomnia have been reported in cases of withdrawal days after discontinuing doses at below 2 g/day (9–12). In outpatient settings, one case describes a patient self-reducing 1 gram daily dose by 50% over the course of 2 weeks without withdrawal symptoms, but another case of a patient taking 8 g/day required baclofen taper over the course of 20 weeks to mitigate withdrawal (2, 10).…”