AIMS: To examine the impact of changes in guidance for take-home doses (THDs) of OAT during COVID-19 on THD prescribing in primary care in Ireland.

METHODS: Cross-sectional data on all prescriptions of OAT (methadone or buprenorphine) in primary care (2018-2023). Weekly percentage change in numbers prescribed 0-1, 2-5, 6-13, ≥14 THDs after the guidance release (13th March 2020) were assessed using interrupted time series autoregressive moving average (ARMA) models assessing immediate (ß) and continued change.

RESULTS: 7367 individuals (31.3% female) were included, mean age 41 (SD 8.5) years at first OAT prescription during the study period. Following the introduction of guidance, an immediate decrease in the percentage of people receiving 0-1 (ß = -4.64; 95%CI -5.67,-3.6; p < 0.001) and 2-5 THDs (ß = -1.86; 95%CI -2.43,-1.3; p < 0.001) was observed, with an immediate increase in those receiving 6-13 (ß = 5.48; 95%CI 5.06,5.91; p < 0.001) and ≥14 THDs (ß = 0.32; 95%CI 0.21,0.43; p < 0.001) of methadone. This initial shift was not maintained in short and long-term trends, with changes in trend resulting in a near reversion to pre-guidance methadone THD patterns by the end of 2023. Buprenorphine THD patterns were still evolving prior to march 2020, but stabilised close to methadone THD levels after the introduction of guidance.

CONCLUSION: After the introduction of COVID-19 emergency guidance, access to methadone THDs increased. However, patterns quickly reverted to pre-pandemic levels. While the number of people receiving buprenorphine increased over the study period, THD stabilised at similar levels to methadone. These finding suggests clinical guidelines updates are needed to achieve sustained changes and support person-centred OAT care in Ireland.