Title:Rapid Metabolism of Monthly Extended-Release Buprenorphine
Formulation: A Case Report
Volume: 12
Author(s): Hossameldin Tolba, Wael Foad and Samer El Hayek*
Affiliation:
- Erada Center for Treatment and Rehabilitation in Dubai, Dubai, United Arab Emirates
Keywords:
Buprenorphine, extended-release, medication-assisted treatment, rapid metabolism, opioid use disorder, case report.
Abstract:
Background: Medication-assisted treatment constitutes the gold standard management
for patients with opioid use disorder. Many factors can alter the response to medications, including
genetic variations. In this case report, we discuss the presentation of a patient maintained on subcutaneous
extended-release buprenorphine formulation who repeatedly presented objective and subjective
signs of opioid withdrawal when he was switched from weekly to monthly formulation. We
particularly highlight the role of metabolic pharmacogenes in this presentation.
Case Presentation: Mr. Y, a 31-year-old single man, presented to our rehabilitation center seeking
assistance for his polysubstance dependence, mainly opioid use disorder. As part of his multidisciplinary
treatment plan, he was started on weekly extended-release buprenorphine. After maintenance
for several months, he was transitioned to the monthly equivalent formulation. Since the transition,
he began to develop severe withdrawal symptoms 1-2 weeks before his next due injection.
This was paralleled by a noted decrease in buprenorphine level on his urine drug screening test. As
soon as the patient was placed back on the weekly formulation, his symptoms resolved.
Conclusion: This is a novel case highlighting the potential role of pharmacogenomics in clinical
presentation and response to medications. Switching patients from weekly to monthly extendedrelease
buprenorphine formulation might make rapid or ultra-rapid metabolizers at risk of earlyonset
withdrawal symptoms. In such a case, earlier provision of the injection or switching to another
formulation or medication can be considered.