Unintentional mortality associated with paracetamol and codeine preparations, with and without doxylamine, in Australia

Introduction Misuse of paracetamol, codeine and doxylamine combination analgesics may lead to addiction and mortality. This study aimed to (1) identify unintentional deaths in Australia associated with use of combination analgesic products containing paracetamol, codeine and doxylamine; (2) describe cases characteristics, including demographics and additional medication use; and (3) identify common factors associated with misuse and mortality of these medicines in Australia. Design This retrospective case series analysed National Coronial Information System data to identify cases of unintentional death attributable to paracetamol, codeine and doxylamine products between 2002 and 2012. Setting Three Eastern Australian states: New South Wales, Queensland, Victoria, comprising a population of approximately 18.6 million people. Results 441 unintentional deaths attributed to paracetamol/codeine products were identified; doxylamine was detected in 102 cases (23%). Overall unintentional death rates rose from 0.9-per-million in 2002 to 3.6-per-million in 2009, declining to 1.9-per-million in 2012. Median age at time of death was 48, half of all cases occurred between 35-54 years of age, and 57% were female. Concomitant medication use was detected in 79% of cases, including benzodiazepines, other opioids, psychiatric medications, alcohol and illicit drugs. Behaviours consistent with drug misuse including doctor/pharmacy shopping, excessive dosages and extended use, were identified in 24% of cases. Conclusions This study identified 441 deaths associated with codeine-combination analgesic products across three Australian states; with an average of 40 deaths per year. Death commonly involved multiple substance use and abuse behaviours indicative of misuse and dependence.