An expanding world of new psychoactive substances—designer benzodiazepines.

• Designer benzodiazepines (DBZD) have recently emerged as recreational drugs. • Vast majority of DBZD are not registered as medications and have not undergone clinical trials. • Phenazepam, etizolam, diclazepam, flubromazolam and pyrazolam are the most prominent drugs. • Use of DBDZ can lead to intoxications and fatalities, especially when combined with other CNS depressants. The abuse of new psychoactive substances (NPS) has been increasing dramatically since the late 2000s worldwide. Between 2009 and 2017, a total of 803 individual NPS were reported to the United Nations Office of Drugs and Crime by 111 countries and territories. Although the most popular compounds are synthetic cannabinomimetics and psychostimulatory derivatives of cathinone (so-called β-keto-amphetamines), novel benzodiazepines have recently emerged on the recreational drug market. The misuse/abuse of "designer benzodiazepines" (DBZD), a common name for the benzodiazepine class NPS, has become an increasing problem in many countries. The DBZD group includes pharmaceutical drug candidates that have never been approved for medical use, compounds that were synthesized by a simple structural modification of a registered drug, and some active metabolites of registered benzodiazepines. This survey presents members of the DBZD group, describes the epidemiological trends and clinical effects associated with DBZD use, and discusses available data on their metabolism. Special emphasis is given to cases of intoxications involving these compounds. [ABSTRACT FROM AUTHOR]