Researchers in the United States have undertaken a retrospective cohort study investigating the proportion of opioid-tolerant patients initiating opioid-tolerant only (OTO) medications. Evidence of opioid tolerance was collected using prescription claims and electronic health record (EHR) data on prescriptions from 2007-2016. Among 153,385 OTO use episodes reported, only 47.7% involved patients with evidence of prior opioid tolerance. Specifically, the proportions of patients with evidence of opioid tolerance prior to beginning therapy with transdermal fentanyl, transmucosal fentanyl, extended-release oxycodone and extended-release hydromorphone were 30.9%, 64.0%, 84.0% and 62.5%, respectively.

These findings are significant because patients without opioid tolerance have an increased risk of potentially fatal overdose. It was also reported that EHR data did not provide significant additional evidence of opioid tolerance not already found in claims data. Prospective studies are required to further understand and characterise the clinical reasoning behind potentially inappropriate and harmful prescribing of OTO medications. The full details of the study can be accessed here.

Contributed by Australian Medication Safety Services Associate – Isabella Singh