Successful switch to transdermal buprenorphine for OA pain of the hip, knee

Conversion to a 7-day regimen of transdermal buprenorphine (Butrans Transdermal System, Purdue Pharma) from a stable regimen of hydrocodone/acetaminophen (Vicodin, Abbott) can be successful in patients with osteoarthritic (OA) pain of the hip or knee, according to a study presented at the annual meeting of the American Academy of Pain Medicine, in National Harbor, Md.

According to this study, 84.3% of patients with OA pain of the knee or hip were successfully converted from a stable hydrocodone/acetaminophen regimen to a 7-day buprenorphine regimen. Patients who received treatment with buprenorphine maintained analgesia, function, and sleep quality. Patients rated buprenorphine positively. Conversion to a low initial dose of buprenorphine may improve overall tolerability.

For this randomized, double-blind, double-dummy, parallel-group study, 198 adult patients with OA receiving a stable dosage of hydrocodone/acetaminophen (15 mg/d to 30 mg/d) were switched to the nearest equivalent dosage of open-label hydrocodone/acetaminophen for 7 days. Patients were then stratified based on their dosage and randomly assigned to treatment with titratable transdermal buprenorphine (10 µg/h to 20 µg/h) or fixed-dose transdermal buprenorphine (20 µg/h). The primary efficacy variable was completion of the 14-day, double-blind phase.

In all, 167 patients completed the 14-day, double-blind phase, and 84.3% were successfully converted to the transdermal regimen. The average proportion of days with successful analgesia was 74%. Overall, 85% patients preferred transdermal buprenorphine to the oral hydrocodone/acetaminophen regimen.

Patients randomly assigned to the lower dose (10 µg) of buprenorphine experienced slightly better tolerability compared with patients who received the higher dose (20 µg). The overall incidence of adverse events was lower in patients treated with titratable buprenorphine (10 µg to 20 µg) than that in the fixed-dose (20 µg) treatment group (52% vs 62%, respectively).