Acute poisoning related to the recreational use of prescription drugs: an observational study from Oslo, Norway

BACKGROUND: Recreational use of prescription drugs is widespread. We describe acute poisonings related to the recreational use of prescription drugs. METHODS: Retrospective observational study. We retrospectively registered all patients presenting from October 2013 through March 2015 at a primary care emergency outpatient clinic in Oslo, Norway, with an acute poisoning related to recreational drug use. We registered demographic data, toxic agents taken, clinical course and treatment. From this data set we extracted the 819/2218 (36.9%) cases involving one or more prescription drugs. RESULTS: Among the 819 included cases, 190 (23.2%) were female. Median age was 37 years. The drugs most commonly involved were benzodiazepines in 696 (85.0%) cases, methadone in 60 (7.3%), buprenorphine in 53 (6.5%), other opioids in 56 (6.8%), zopiclone/zolpidem in 26 (3.2%), and methylphenidate in 11 (1.3%). Prescription drugs were combined with other toxic agents in 659 (80.5%) cases; heroin in 351 (42.9%), ethanol in 232 (28.3%), amphetamine in 141 (17.2%), cannabis in 70 (8.5%), gamma-hydroxybutyrate (GHB) in 34 (4.2%), cocaine in 29 (3.5%), and other illegal drugs in 46 (5.6%). The patient was given naloxone in 133 (16.2%) cases, sedation in 15 (1.8%), and flumazenil in 3 (0.4%). In 157 (19.2%) cases, the patient was sent on to hospital. CONCLUSIONS: One in three acute poisonings related to recreational drug use involved prescription drugs. Benzodiazepines were by far the most common class of drugs. Prescription drugs had mostly been taken in combination with illegal drugs or ethanol.