Nonmedical use of benzodiazepines and Z-drugs in the UK.

There is little overlap between benzodiazepine and Z-drug NMU suggesting distinct nonmedical use of the drugs; future studies need to explore whether this relates to personal preference, drug availability or other factors. A significant proportion are acquiring these drugs for NMU without a prescription, so without guidance and monitoring from a medical practitioner. While the dangers of mixing benzodiazepines and heroin/other opioids are well documented, there is a paucity of data regarding concomitant NMU of benzodiazepines and stimulant drugs, or NMU of Z-drugs and opioids, and, given the prevalence of these combinations, this requires further investigation.