Designer benzodiazepines: an update

Designer benzodiazepines (DBs) are a subclass of novel psychoactive substances (NPS). DBs mimic the properties of approved and prescribed benzodiazepines.A systematic search of literature on DB classification, structure-activity relationships, pharmacologic properties, and adverse effects.The prevalence of DB use has increased substantially over the last decade. All DBs are full-agonist ligands at the gamma-aminobutyric acid type A-benzodiazepine (GABAA-BZ) receptor system. This is not surprising, since DBs largely represent either minor structural modifications, or well-recognized active metabolites, of existing approved benzodiazepines. As such, the pharmacologic profile and associated risks and hazards of DBs are similar or identical to clinically approved and legitimately prescribed benzodiazepines, most of which have been in use for decades. Concurrent use of DBs along with other abusable or recreational drugs (alcohol, opioids, cocaine, stimulants, hallucinogens, other sedative-hypnotics) represents the principal public health risk. The increasing illicit availability and use of DBs is of concern and requires regulatory attention, but DBs do not rank highly among designer psychotropic agents in terms of health risk to humans.