Psychoactive prescription drug use disorders, misuse and abuse Pharmacoepidemiological aspects

ii Psychoactive prescription drug use disorders, misuse and abuse iii All the passionate work I put into this thesis is dedicated to my parents, who always emphasized the importance of knowledge and of caring for the less fortunate. Background: There is a widespread and increasing use of psychoactive prescription drugs, such as opioid analgesics, anxiolytics, hypnotics and anti-epileptics, but their use is associated with a risk of drug use disorder, misuse and abuse. Today, these are globally recognised and emerging public health concerns. Aim: The aim of this thesis is to estimate the occurrence and prevalence of psychoactive prescription drug use disorders, misuse and abuse, and to investigate the association with some potential risk factors. Methods: A study using register data from forensic cause of death investigations analysed and described cases of fatal unintentional intoxications with tramadol (Study I). Based on register data on spontaneously reported adverse drug reactions (ADRs) reported cases of tramadol dependence were scrutinized and summarised (Study II). In a study in suspected drug-impaired drivers with a toxicology analysis confirming intake of tramadol, diazepam, flunitrazepam, zolpidem and zopiclone, the prevalence of non-prescribed use was assessed and associated factors were investigated (Study III). From a national cohort of patients initiating prescribed treatment with pregabalin, identified using data on prescription fills, a study investigated longitudinal utilisation patterns during five years with regards to use above the maximum approved daily dose (MAD) of the drug, and factors associated with the utilisation patterns (Study IV). Results: In the first study, 17 cases of unintentional intoxications were identified, in which tramadol was judged to have caused or contributed to the death. Of the deceased, more were men, the median age was 44 years and the majority used multiple psychoactive substances (prescription drugs, alcohol and/or illicit drugs). In the second study, 104 spontaneously vi reported cases of possible or probable tramadol dependence were identified, of which more concerned women. The median age in these cases was 45 years and in about a third of cases the person had a history of substance abuse and in 40% of cases there was documented history of psychoactive medication use. Severe addiction was reported. In the third study, more than half of the individuals suspected of drug-impaired driving used the drug without a recent prescription. Non prescribed use was most frequent in users of benzodiazepines and of tramadol compared to users of zolpidem or zopiclone, and was …