An Unusual Presentation of an Uncommon Drug: A Case Report on Phenibut Overdose

Phenibut (β-phenyl-γ-aminobutyric acid), a nootropic, gamma-aminobutyric acid receptor agonist, commercially marketed for anxiolysis, is increasingly recognized for its recreational abuse potential. We present the case of a 30-year-old-male with a history of polysubstance abuse, anxiety, and depression, who presented to the Emergency Department by ambulance for altered mental status with severe agitation, requiring both sedation and mechanical ventilation. It was later discovered that he had consumed phenibut, which he purchased through the internet. Currently, no readily available confirmatory laboratory tests exist to aid in the diagnosis of acute phenibut intoxication. We highlight the clinical distinctions between features of acute phenibut intoxication and withdrawal.