The challenge of complex drug use: Associated use of codeine-containing medicines and new psychoactive substances in a European cross-sectional online population.

OBJECTIVE: Misuse of codeine-containing medicines in combination with new psychoactive substances (NPS) is inadequately described. This study characterises codeine consumption amongst NPS users and non-NPS users to provide warning of health issues.

METHODS: Online survey conducted between July 2015 and March 2016.

RESULTS: Out of 340 respondents, residing in a country in Europe and using codeine recently, 63.8% were female. Mean age: 34.9 years (SD = 12.4). Substance use included NPS (18.5%) and illicit controlled drugs (55.9%). Factors relating to codeine use found to significantly predict NPS use were consuming codeine extracted from combination tablets (OR = 16.79, 95% CI [8.67, 32.51]), obtaining codeine from friends, family, and acquaintances (OR = 3.98, 95% CI [1.82, 8.7]), use of illicit controlled drugs (OR = 34.99, 95% CI [8.39, 145.94]) and use of codeine to experience euphoria (OR = 6.41, 95% CI [3.42, 12.04]).

CONCLUSIONS: Amongst NPS users, codeine is less likely to be used daily but more likely to be used for recreational purposes. Smaller populations engaging in high-risk use exist who take multiple drugs in high doses. Combinations of misused codeine and NPS highlight the need for policy to respond to a more complex drug situation.