Opioid analgesic prescribing in Australia: a focus on gender and age

Abstract

Purpose: The use of prescription opioid analgesics has been increasing over the last few decades in Australia. In particular, oxycodone and fentanyl have increased substantially. We examined the gender and age trends in the prescribing of subsidised opioid analgesics in the Australian population for non-palliative care indications.

Methods: We analysed the Medicare Australia and Drug Utilisation Sub-Committee databases for prescription data from 2002 to 2009 in 10-year age groups and by gender. Prescriptions were converted to Defined Daily Doses (DDD)/1000/day using Australian Bureau of Statistics population data.

Results: Overall use increased progressively in 2002-2009 from 12.95 to 16.08 DDD/1000 population/day (average annual increase 3.4%). Codeine was the most widely used agent followed by tramadol then oxycodone. Dispensed use increased in those aged in their 20s and 30s to plateau between 30 and 59 years for the three most preferred analgesics. The peak use of higher dose formulations of oxycodone was seen in males from 40 years. The highest dose formulation of tramadol was preferred in those aged up to approximately 70 years.

Conclusions: Reasons for increased use may include increased prevalence of people with cancer and use for acute pain. The overall benefit and risk in this escalation of opioid use are difficult to determine; however, the increasing risk of tolerance, dependence, overdose and drug diversion suggests to clinicians and policy makers that this escalation may not be in the best interest of all Australians.

Keywords: analgesics; fentanyl; opioids; oxycodone; pharmacoepidemiology; prescribing.