Comparative risks of opioid overdose in patients on oxycodone initiating selective serotonin reuptake inhibitors.

Background: Selective-serotonin reuptake inhibitors (SSRIs) are often co-prescribed with oxycodone, yet may potentiate respiratory depression. We aimed to assess the comparative effects of SSRIs on opioid overdose when added to oxycodone.

Methods: Using US commercial and public health insurance claims data (2004-2020), we conducted a cohort study in adults who initiated SSRI while on oxycodone. We assigned patients to one of five exposures (sertraline, citalopram, escitalopram, fluoxetine, paroxetine) and followed them for opioid overdose (hospitalization or emergency room visit) for 365 days and while they stayed on both oxycodone and index SSRI. We used propensity score matching weights to adjust for potential confounders and weighted Cox proportional hazard models to estimate hazard ratios (HRs) with 95% confidence intervals (CI).

Results: Among 753,263 eligible individuals (mean age 46 years [SD 16]; 527,340 females [70%]), 221,792 initiated sertraline, 173,352 citalopram, 153,968 escitalopram, 126,954 fluoxetine, and 77,197 paroxetine. Overall, 1250 opioid overdose events occurred, with incidence rates ranging from 10.8 to 15.2 per 1,000 person-years across individual SSRIs. Weighted HRs, relative to sertraline, were 1.24 (95% CI, 1.04 - 1.50) for citalopram, 1.22 (95% CI, 1.01 - 1.47) for escitalopram, 1.26 (95% CI, 1.04 - 1.53) for fluoxetine, and 1.26 (95% CI, 1.01 - 1.57) for paroxetine. No differences were observed across SSRIs other than sertraline.

Conclusions: In this study of individuals who added an SSRI to oxycodone, incidence of opioid overdose was low. Patients who initiated sertraline experienced overdose at a slightly lower rate than patients who initiated other SSRIs.