Phenibutan—an Illegal Food Supplement With Psychotropic Effects and Health Risks

Area of Science:

• Pharmacology
• Toxicology
• Neuroscience

Background:

• Phenibut (β-phenyl-γ-aminobutyric acid) is a neurotransmitter analog of gamma-aminobutyric acid (GABA).
• It functions similarly to gabapentinoids like abapentin and pregabalin by inhibiting voltage-dependent presynaptic calcium channels (α2-δ-subunits).
• The safety and potential harms associated with gabapentinoid use are subjects of ongoing scientific discussion.

Purpose of the Study:

• To review the toxicity profile of Phenibut.
• To compare Phenibut's effects with those of gabapentinoids and benzodiazepines.
• To analyze reported cases of Phenibut intoxication and its association with other substances.

Main Methods:

• A selective literature search was conducted.
• Cases reported to the Giftinformationszentrum-Nord (GIZ-Nord), a German poison control center, were analyzed.
• Data from 2008-2022 on Phenibut, gabapentin, and pregabalin inquiries were reviewed.

Main Results:

• Phenibut toxicity resembles gabapentinoids and GABA mimetics, presenting with benzodiazepine-like withdrawal symptoms, including seizures and delirium.
• While most Phenibut intoxications were mild, overdose cases (2-100 g) often resulted in somnolence, necessitating intensive care.
• No Phenibut-related deaths were reported in Germany or Western Europe, though co-ingestion with opiates may increase risks.

Conclusions:

• Phenibut exhibits toxicity patterns similar to gabapentinoids and benzodiazepines.
• Concurrent use with other psychotropic drugs, particularly opiates, may elevate the risk of severe outcomes like coma and respiratory depression.
• Phenibut remains largely unrecognized in Western medicine, potentially leading to underreported cases of intoxication and associated fatalities.