Low-dose transdermal buprenorphine - long-term use and co-medication with other potentially addictive drugs

Abstract

Introduction: Recently, low-dose transdermal buprenorphine (LD-TD-BUP) was introduced for treatment of patients with chronic non-malignant pain. The primary aim of this study was to determine the proportion of patients who were prescribed LD-TD-BUP for non-malignant pain who became long-term users. The secondary aim was to determine the proportion of patients who co-medicated with other opioids or benzodiazepines during treatment with LD-TD-BUP.

Methods: Data were drawn from the Norwegian Prescription Database that covers all prescriptions dispensed at pharmacies to the entire Norwegian population (4.7 million inhabitants). The study population consisted of all patients who were dispensed at least one prescription of LD-TD-BUP from its introduction in November 2005 to 31 December 2008. Patients who were dispensed more than 24 patches (≥ 6 months) were defined as long-term users. Reimbursement codes were used to stratify patients as having cancer pain or non-malignant pain.

Results: Among new users of LD-TD-BUP for non-malignant pain (n = 13,451), only 22% became long-term users, while 44% were only dispensed one prescription. Among long-term users who were opioid naive when LD-TD-BUP was initiated, 43% co-medicated with other opioids or benzodiazepines, compared with 82% of those who previously had used opioids.

Conclusion: Three years after introduction, 0.4% of the Norwegian population had been dispensed LD-TD-BUP. Only one-fifth had become long-term users. Those who used opioids before the first dispension of LD-TD-BUP co-medicated with other potentially addictive drugs to a much higher degree compared with those who were opioid naive.