Objective: Buprenorphine is a medication for opioid use disorder that reduces mortality. This study aims to investigate the less well-understood relationship between the dose in the early stages of treatment and the subsequent risk of death.
Methods: We used Kentucky prescription monitoring data to identify adult Kentucky residents initiating transmucosal buprenorphine medication for opioid use disorder (January 2017 to November 2019). Average daily buprenorphine dose for days covered in the first 30 days of treatment was categorized as ≤8 mg, >8 to ≤16 mg, and >16 mg. Patients were followed for 365 days after the first 30 days of buprenorphine treatment. Endpoints were opioid-involved overdose death and death from other causes. Causes and dates of death were obtained using Kentucky death certificate records. Associations were evaluated using multivariable Fine and Gray models adjusting for patient baseline characteristics.
Results: In the cohort of 49,857 patients, there were 227 opioid-involved overdose deaths and 459 deaths from other causes. Compared with ≤8 mg, the adjusted subdistribution hazard ratio (aSHR) of opioid-involved overdose death decreased by 55% (aSHR, 0.45; 95% confidence interval [CI], 0.34-0.60) and 64% (aSHR, 0.36; 95% CI, 0.25-0.52) for patients receiving doses of >8 to ≤16 mg and >16 mg, respectively. The incidence of death from other causes was lower in patients receiving >8 to ≤16 mg (aSHR, 0.78; 95% CI, 0.62-0.98) and >16 mg (aSHR, 0.62; 95% CI, 0.47-0.80) versus ≤8 mg dose.
Conclusions: Higher first 30-day buprenorphine doses were associated with reduced opioid-involved overdose death and death from other causes, supporting benefit of higher dosing in reducing mortality.