Therefore, the description of case reports related to phenibut misuse is crucial in order to make clinicians aware of this emerging NPS misuse.Ī 50-year-old woman with previously unknown psychiatric history was admitted to the emergency department at night in a state of confusion and psychomotor agitation. However, the clinical manifestation characterized by non-specific signs and symptoms together with the lack of a specific protocol for the treatment of both phenibut intoxication and withdrawal symptoms could delay the recognition of these syndromes and their effective management. These clinical conditions must be timely recognized and treated in order to avoid serious complications, such as respiratory or acute renal failures due to rhabdomyolisis ( 5).

Specifically, intoxication mainly induces the risk of respiratory failure, paradoxical agitation, seizures, and delirium, while withdrawal is a condition that can last for a significant period and is characterized by psychomotor agitation, psychosis, autonomic instability, seizures, nausea, and vomiting ( 6, 7). In this regard, both acute intoxication and withdrawal syndromes related to phenibut consumption have been reported in literature ( 5). However, even though its medical use is not approved in western and European countries, since it was classified as a novel psychoactive substance (NPS) by the United Nations Office of Drug and Crime (UNODC), phenibut can be easily obtained worldwide via the Internet as a dietary supplement in the form of powder, pills, or crystals with an increasing risk of potential misuse ( 4). The pharmacological characteristics of phenibut can be viewed in Table 1. Moreover, phenibut seems also to boost both dopaminergic and serotoninergic neurotransmission ( 3). This substance seems to primarily act as a γ-aminobutyric acid (GABA) B receptor agonist, consequently closing voltage-dependent calcium channels and inhibiting neurotransmission, similar to other drugs, such as pregabalin, gabapentin, and baclofen ( 2). Phenibut (4-amino-3-phenyl-butyric acid) is a glutamic acid derivative compound synthesized in Russia in the early 1960s and available nowadays in ex-Soviet countries as a cognitive enhancer, food supplement, adjuvant for anxiety and insomnia, and alcohol withdrawal symptoms ( 1). This is a scientifically significant report as it provides therapeutic and outcome data concerning a syndrome that is still quite unfamiliar. Results: The suspicion of phenibut withdrawal allowed to establish the appropriate management, leading to the restitutio ad integrum of the psychopathological case.Ĭonclusions: In the face of an incoercible psychomotor agitation case, the knowledge of the so-called novel psychoactive substances allows for more appropriate clinical management of intoxication and withdrawal syndromes. She was hospitalized at the psychiatry ward for 25 days and gave her consent for the publication of the present case report. Methods: In this case report, a 50-year-old woman was admitted to the emergency room with psychomotor agitation, psychotic symptoms, and insomnia, and was non-responsive to treatment. In recent years, some case reports have, therefore, highlighted episodes of acute toxicity or withdrawal, but it is still a largely unknown phenomenon. Although its medical use is not approved in western countries, it can be easily obtained worldwide via the Internet, so it spread as a substance of abuse. 2Department of Pathophysiology and Transplantation, University of Milan, Milan, Italyīackground and Objectives: Phenibut (4-amino-3-phenyl-butyric acid), acting as a GABA-B receptor agonist, has a beneficial effect on anxiety.1Department of Neurosciences and Mental Health, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.Cecilia Maria Esposito 1, Gian Mario Mandolini 1, Giuseppe Delvecchio 2, Alessio Fiorentini 1 * and Paolo Brambilla 1,2

Phenibut pregabalin cross tolerance