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Background: Phenibut (β-phenyl-γ-aminobutyric acid) is an analog of the neurotransmitter gamma-aminobutyric acid (GABA). Like abapentin and pregabalin, it inhibits α2-δsubunits of voltage-dependent presynaptic calcium channels. The potential harm resulting from the use of these gabapentinoids is currently a matter of debate. Methods: This review is based on pertinent publications retrieved by a selective literature search and on cases reported to the Giftinformationszentrum-Nord (GIZ-Nord), a poison information center at the University of Gttingen, Germany. Results: Phenibut is a prescription drug in Russia but its production, possession, use, trafficking, or administration is illegal in Germany. The phenibut toxicity syndrome resembles that of gabapentinoids and GABA mimetics: benzodiazepine-like withdrawal symptoms including epileptic seizures, delirium and paradoxical activation have been described, as have cases of abuse and dependence. A few cases of use in the setting of multidrug abuse, and of phenibut-related death, have been described to date in the USA. The GIZ-Nord received 17 inquiries about phenibut, 55 about gabapentin, and 126 about pregabalin over the period 20082022. Over the same period, the GIZ-Nord was informed of 1207 cases involving Z substances and 4324 involving benzodiazepines. In the majority of the registered intoxications, including those with phenibut, the symptoms were mild. Overdoses of phenibut (2100 g) were reported in 15 of the 17 cases; 8 of the persons who had taken an overdose were somnolent. In such cases, observation in intensive care was recommended. Respiratory depression or coma was not encountered in any case, not even in the patient who had taken 100 g of phenibut. Conclusion: Phenibut causes symptoms resembling those of gabapentinoid and benzodiazepine use. There have been reports of phenibut use in combination with other psychotropic drugs; in particular, its use together with opiates could increase the risk of coma and respiratory depression. No deaths due to phenibut intoxication have been published in Germany or elsewhere in Western Europe, although such cases may have been overlooked, as this drug is still largely unknown to Western medicine. [ABSTRACT FROM AUTHOR]

Michael Soyka1,21Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-Universität, Munich, Germany; 2Private Hospital Meiringen, Meiringen, SwitzerlandAbstract: Opioid maintenance therapy is a well-established first-line treatment approach in opioid dependence. Buprenorphine, a partial opioid agonist, has been found by numerous studies to be an effective and safe medication in the treatment of opioid dependence. At present, buprenorphine is available as a monodrug or in a fixed 4:1 ratio combination with naloxone. A diminished risk of diversion and abuse for the buprenorphine–naloxone combination is likely but not firmly established. Conventional formulations are given sublingually to avoid the hepatic first-pass effect. A novel film tablet is available only in the US and Australia. Other novel, sustained-release formulations (implant, depot) are currently being developed and tested. Recent studies, including a Cochrane meta-analysis, suggest that the retention with buprenorphine is lower than for methadone, but that buprenorphine may be associated with less drug use. Higher doses of buprenorphine are associated with better retention rates. Buprenorphine has a ceiling effect at the opioid receptor with regard to respiratory depression, and may cause fewer fatal intoxications than methadone. Possible antidepressant effects of buprenorphine and its use in comorbid psychiatric patients has not been studied in much detail. Clinical implications are discussed.Keywords: buprenorphine, methadone, naloxone, opioids, opioid dependence, therapy

Ulrich W Preuss,1 Jörg Zimmermann,2,3 Gabriele Schultz,2 Anna Watzke,2 Peggy Schmidt,4 Bärbel Löhnert,5 Michael Soyka2,61Department of Psychiatry, Psychotherapy and Psychosomatics, University of Halle-Wittenberg, Halle, Germany; 2Ev Krankenhaus Bethanien GmbH, Fachklinik Gristower Wiek, Johanna-Odebrecht-Stiftung, Germany; 3Karl-Jaspers-Klinik, Fachkrankenhaus für Psychiatrie und Psychotherapie, Psychiatrieverbund Oldenburger Land, Germany; 4Department of Psychiatry, Ludwig-Maximilians-Universität Munich, Germany; 5Klientenzentrierte Problemberatung, Dachau/Munich, Germany; 6Privatklinik Meiringen, Meiringen, Switzerland Background: Rehabilitation treatment noncompletion is considered a risk factor for long term relapse in alcohol-dependent individuals. The aim of this analysis of in- and outpatients in alcohol dependence rehabilitation in Germany is to identify social, mental, and somatic risk profiles for treatment noncompletion.Methods: A total of 92 individuals from an outpatient program and 303 individuals from two inpatient rehabilitation treatment units in three different locations in Germany were recruited and assessed with a structured interview and several measures of psychopathology (personality disorders, anxiety, depression, and impulsivity) at treatment admission, with termination at 12 months follow-up. Participants were subdivided into treatment completers and noncompleters for any reason.Results: A total of 10.2% of inpatients and 16.1% of outpatients did not complete treatment. Compared with treatment completers, noncompleters had a significantly lower rate of continuous abstinence at 1-year follow-up, more recent alcohol consumption before admission, and a higher rate of borderline personality disorders. Among inpatients, an elevated rate of lifetime mental disorders, depression, and suicide attempts was found among treatment noncompleters; among outpatients, treatment noncompleters were more often than completers to be married but live separated.Conclusion: Rates of treatment noncompletion in inpatient and outpatient rehabilitation programs correspond to results from previous research. Noncompletion is a significant correlate of relapse 1 year after treatment, and noncompleters show an elevated level of psychopathology. These findings may help rehabilitation treatment facilities to tailor specific therapies for these individuals to reduce risk for treatment noncompletion.Keywords: alcohol dependence, rehabilitation treatment, noncompletion, inpatient, outpatient