Trends in Buprenorphine Dosage and Days Supplied for New Treatment Episodes for Opioid Use Disorder, 2010-2019.

Background: Buprenorphine reduces risk of opioid overdose mortality. However, its benefits are limited by low retention, particularly in early treatment. Optimizing initial dosage may impact retention. However, little is known about the prescription characteristics of new buprenorphine treatment episodes.Methods: In a US sample of commercial and employer-sponsored pharmacy claims, we identified new buprenorphine treatment episodes (days 1-30) from individuals >= 16 years following 90 days without buprenorphine from 2010 to 2019. Outcomes included first prescription average days supplied, first prescription average daily dosage, and average dosage on days 2, 8, 15 and 30.Results: We identified 117,793 new episodes among 96,451 unique individuals. Episodes per 10,000 person-years decreased slightly over time. Stratifying by age, sex and region demonstrated decreasing episodes among individuals <= 34 years and increasing episodes among individuals >= 35 years. From 2010-2019, first prescription average days supplied and daily dosage decreased from 17.1 to 15.3 days and 13.6 mg to 11.6 mg, respectively. Simultaneously, the proportion of episodes without possession and with dosages <16 mg increased across all days and years. By day 30, episodes without buprenorphine possession grew from 27.9% to 30.8% and episodes involving dosages of <16 mg grew from 26.4% to 33.4%.Conclusions: We found that buprenorphine dosage and days supplied for new treatment episodes decreased from 2010 to 2019 while buprenorphine possession worsened. Further investigation examining the relationship between buprenorphine dosage and retention in the early treatment period is needed.