Outpatient cross-titration to buprenorphine for chronic pain: A retrospective analysis

Abstract

Objective: To determine the effectiveness and safety of the University of Washington's buprenorphine cross-titration protocol for chronic pain in the outpatient setting. Methods: Retrospective chart review was performed on 150 patients transitioned from full μ-opioid agonist therapy to buprenorphine using the University of Washington Medical Center Pain Clinic's cross-titration protocol between September 1, 2020, and December 31, 2021, in an outpatient setting. Primary outcome was to determine the percentage of patients who completed the cross-titration and continued buprenorphine without full μ-opioid agonists 4 weeks after completion. Secondary outcomes included final buprenorphine dose, days needed to complete cross-titration, deviation rates from the protocol, and opioid-related adverse events. Results: Fifteen of 31 (48.4 percent) included patients successfully converted to buprenorphine. Median duration of successful cross-titration was 29 days (interquartile range 19-57). Average end-titration dose for patients on buprenorphine/naloxone sublingual films was 7.9 ± 5.7 mg/day, while for buprenorphine transdermal (TD) patches, it was 11.9 ± 4.8 mcg/h. Morphine equivalent daily dose (MEDD) prior to induction varied widely. All patients transitioned to TD buprenorphine were taking ≤30 mg MEDD. Patients previously taking >120 mg MEDD stabilized on 8-16 mg/day buprenorphine. Most common reasons for cross-titration failure were inadequate pain control and intolerable adverse effects. Discussion: The University of Washington's buprenorphine cross-titration protocol for chronic pain was successful in about half of included patients undergoing conversion from chronic full μ-opioid agonist therapy and generally well tolerated. Clinical responses were widely variable, and many required slower taper and higher end-titration buprenorphine dose than anticipated. Although protocols provide structure for cross-titration, each course should be monitored closely and individualized.