Morbimortality consequences of use and misuse of psychoactive medicines in Portugal

AIMS: To characterize the morbidity and mortality consequences of psychoactive medicines use and misuse in Portugal. METHODS: Retrospective multisource database study to estimate the risk of psychoactive medicine-related deaths, emergency department admissions, serious poisoning calls and serious adverse drug reaction reports, including combination with alcohol and illicit drugs. RESULTS: Most intentional exposures to psychoactive medicines involving combinations (n = 5973; 70.2%), antidepressants (n = 5441; 67.1%) or any prescription opioid (n = 355; 67.4%) resulted in serious poisonings (i.e., medical assistance advised). The risk of serious poisoning was higher for exposures involving substance combinations (relative risk [RR] = 1.12; confidence interval [95% CI): 1.10-1.14), antidepressants (RR = 1.04; 95% CI: 1.02-1.05) and alcohol and/or illicit drugs (RR = 1.18; 95% CI: 1.15-1.21). Among 6737 psychoactive medicine-related deaths, 166 (2.5%) were identified where the medicine contributed to the fatal outcome. The risk of contribution to death was higher in cases involving substance combinations (RR = 9.03; 95% CI: 3.71-21.94), antidepressants (RR = 3.20; 95% CI: 2.28-4.49), and alcohol and/or illicit drugs (RR = 1.88; 95% CI: 1.36-2.61). Emergency department admission caused by misuse of a psychoactive medicine (n = 5826) were more likely to involve benzodiazepines/z-drugs (RR = 2.40; 95% CI: 2.30-2.51) or antidepressants (RR = 1.86; 95% CI: 1.80-1.93). CONCLUSIONS: Psychoactive medicine misuse in Portugal frequently occurs alongside polysubstance use and is associated with substantial health risks. Public health strategies should prioritize addressing high-risk medicine combinations and therapeutic groups most often found to trigger negative outcomes. This may be achieved by targeted prevention efforts integrated into health system design.