The Role of Gabapentinoids in the Substance Use Pattern of Adult Germans Seeking Inpatient Detoxification Treatment - A Pilot Study

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

BACKGROUND

Phenibut (β-phenyl-γ-aminobutyric acid) is an analog of the neurotransmitter gamma-aminobutyric acid (GABA). Like abapentin and pregabalin, it inhibits α2-δ-subunits of voltagedependent 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 Göttingen, 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 with - drawal 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 2008-2022. 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 (2-100 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.

[Comparative Harm/Benefit Analysis of Various Psychotropic Substances from the Perspective of German Drug Users and Addiction Medicine Experts - A Contribution to Psychoeducation of Substance-Addicted Individuals and Restriction/Legalization Debates]

BACKGROUND

To date, we cannot find any current international comparative study on the assessment of a benefit/harm profile of various licit and illicit psychoactive substances conducted by adult drug users and addiction experts as well. Particularly, there is no study from the German-speaking area of Western Europe.

METHODS

In addition to the data already published by 101 German addiction medicine experts (published in this journal, [1]), we carried out interviews using a structured questionnaire with 100 German substance dependent users, residing in acute and rehabilitation clinical setting, to evaluate 34 psychoactive substances regarding their health and social harm potential for users and others as well as their potential benefit.

RESULTS

Both, users and experts estimated traditional illicit drugs, such as heroin, crack/cocaine and methamphetamine, to be particularly harmful. Synthetic cannabinoids, alcohol and benzodiazepines were in the upper midfield, cannabis and psychotropic mushrooms in the lower midfield, and gabapentinoids at the bottom of the harm rankings of both, users and experts. In comparison with the experts, the users estimated methadone and benzodiazepines to be significantly more harmful. In the benefit analysis, users rated traditional illicit drugs including cannabis and psychotropic mushrooms as well as nicotine as significantly more useful than the experts. In contrast to the experts (traditional illicit drugs), the users did not assess any substance as very harmful and very useless at the same time. Only a few users reported to have experiences with opioid analgesics which, however, did not differ between the users´ and experts´ harm/benefit-assessments. Neither users nor experts predicted cannabis-legalization to change the overall risk potential of cannabis. Specific cognitive valuation biases seemed to be prominent in both groups.

CONCLUSION

This study presents first harm/benefit assessments of psychotropic substances from the perspective of German addiction medicine experts and drug users. The results can be valuable to the psychoeducation of substance-addicted individuals and to current restriction or legalization debates.

Differences between users' and addiction medicine experts' harm and benefit assessments of licit and illicit psychoactive drugs: Input for psychoeducation and legalization/restriction debates

Background

There is a lack of benefit/harm assessments of illicit and licit psychoactive substances performed by substance-dependent users in comparison to addiction medicine experts.

Methods

We extended the analyses of substance harm/benefit assessments of German addiction medicine experts (N = 101), in parts reported recently in this journal [doi.org/10.3389/fpsyt.2020.59219], by the perspectives of substance-addicted persons. The same questionnaire as used for the abovementioned "experts-study" was handed out to inpatient detoxification or rehab treatment seeking German substance-dependent adults (N = 117) for a subsequent structured interview about harms and benefits of 33 new and traditional psychoactive substances comprising also prescription drugs.

Results and discussion

Both, users and experts, ranked the traditional illicit psychoactive substances heroin, cocaine and amphetamines within the top overall harm level group. Synthetic cannabinoids, alcohol and benzodiazepine were in a subordinate top-harm level position. Both cohorts also ranked methadone, nicotine and cannabis within the midrange and buprenorphine as well as psychotropic mushrooms within the lowest harm level positions. Experiences with prescription drugs (including opioidergic analgesics and gabapentinoids), cathinones, GHB, methamphetamine and methylphenidate was not prevalent in our user population. The same applied to barbiturates, propofol, kratom, ayahuasca with nearly zero assessments for each substance. The most user-experiences (>50% per assessed substance) were reported with nicotine, cannabis, alcohol, cocaine, heroin, amphetamine and methadone (core group). The user's overall harm ratings in terms of these psychoactive substances were similar to those of the experts with the exception of the methadone assessment which was rated by the experts to be significantly less harmful if compared with the users' estimation (supposed "treatment bias" of experts). The users' benefit ratings for the traditional illicit psychoactive substances, cannabis as well as for nicotine were significantly more positive in comparison to those of the experts (supposed "attraction bias" of users). Both, experts and users, ranked the harms arising from the use of alcohol or benzodiazepines (usually unregulated substances) higher than the harms caused by the use of methadone, cannabis or psychotropic mushrooms (regulated by most Western narcotic acts). Users attributed the most benefits to buprenorphine, methadone and cannabis. This might reflect a main limitation of the study as the data are from an user population comprising over 50% patients who sought detoxification-treatment of opiates where methadone and buprenorphine are usual transient medications (supposed "selection bias").

Conclusion

This study addressed current trends of psychoactive substance abuse (e.g., synthetic cannabinoids, prescription drugs) and provides from both perspectives (that of the user and that of the addiction medicine experts) robust harm/benefit evaluations at least of a core group of psychoactive substances (traditional illicit psychoactive substances, cannabis, methadone, alcohol and nicotine). The results of this study can be valuable to the psychoeducation of substance-addicted individuals and to current restriction/legalization debates, especially in the Western-EU.