orphine provides an effective and sustained dose-dependent analgesia irrespective of patient age or pain syndrome. A number of studies have been conducted to assess the analgesic efficiency and tolerability of buprenorphine TDS in long-term management of cancer and non-cancer pain. In the long-term study referred to above (Likar et al 2005), 90% of the 239 patients (age range 27–86 years; mean 68 years) reported at least satisfactory pain relief. Forty-three percent of patients rated their pain relief as good and complete. In a post-marketing surveillance study over a total period of 9 months in 13179 patients with cancer and non- cancer pain (age range 13–101 years; mean 68 years), 81% reported pain relief to be “good” or “very good” at the end of the study, whereas only 6% of the study population considered that their previous analgesic treatment fell into these categories (Griessinger et al 2005). The demographics of this study emphasize the efficacy of buprenorphine TDS in a wide range of pain conditions. The patient population in this study included 3690 (28%) with cancer pain, the most common specific diagnosis being lower respiratory tract cancer, urogenital cancer, and breast cancer. Metastases were present in 15% of cancer patients. Among the 9489 patients suffering from non-cancer pain, musculoskeletal pain was the most frequently reported condition (77%), pre- dominantly back pain and joint/rheumatic pain. Neurogenic pain (23%) was mainly a result of neuralgias, neuropathies, or phantom pain. In the long-term study (Likar et al 2005), patients were allowed to control pain by sublingual buprenorphine tablets as needed. The proportion of patients needing 1 mg buprenorphine daily (ie, one tablet in addition to the patch) remained remarkably stable throughout the first 6 months of the study indicating dose stability of buprenorphine under long-term conditions. In another postmarketing surveillance study on transdermal fentanyl in cancer patients over a period of 4 months, it was found that most patients required a dose increase during the observation period, the median dose increasing from 1.2 mg/day to 2.4 mg/day (Radbruch et al 2001). The transdermal application reduces the occurrence of adverse events since the plasma buprenorphine concentra- tion remains stable. In the post-marketing surveillance study of buprenorphine use, out of a total of 13 179 patients, 520 (4%) experienced nausea and 210 (1.6%) experienced vomiting. Constipation was reported in 1.0% of the subjects. A subgroup analysis of elderly patients (> 60 years) found little change in this value (1.1%) (Griessinger et al 2005). This compares favourably with a survey of the use of Therapeutics and Clinical Risk Management 2006:2(1) Safety of pain management with transdermal buprenorphine transdermal fentanyl in 1005 patients (mostly with cancer pain) where the incidence of constipation was 4% (Radbruch et al 2001). Buprenorphine has a lower risk of CNS-related adverse events than other opioids. A comparison of the two surveys mentioned above found the incidence of CNS effects in patients receiving long-term transdermal buprenorphine was lower than in patients receiving long-term transdermal fentanyl. Somnolence, hallucinations, vertigo, and convulsions were experienced by 0.8%, 0.009%, 0.002%, and 0.001% of the subjects in the buprenorphine survey but by 4.0%, 0.2%, 1.0%, and 0.1%, respectively, in the fentanyl survey. One and half percent of the buprenorphine patients reported dizziness (data unavailable in fentanyl patients) which may in some instances respond to a dopamine antagonist. Local skin reactions at patch site may occur and clinical trials have shown that such occurrences are irrespective of whether buprenorphine or placebo were involved. These reactions are most likely due to patch material or adhesive. In a study comparing three different dose strengths of buprenorphine TDS with placebo, patch application was well tolerated, only 10% to 20% of all subjects in all four groups reported local adverse events, but these were not statistically significant. Local skin reactions, predominately consisted of mild to moderate erythema or pruritus lasting less than 24 hours (Böhme and Likar 2003). In a long-term study of buprenorphine use, local skin reactions at the patch site occurred in 20.5% of patients. Most frequently these were erythema (12.1%), pruritus (10.5%), and exanthema (8.8%) (Likar et al 2005). In the post-marketing surveillance study, the overall occurrence of local adverse effects was much lower. Contact dermatitis was seen in only 0.8% of the subjects and pruritus in only 0.7% (Griessinger et al 2005). Adherence to therapy or compliance is a major prerequisite for therapeutic success in the treatment of chronic pain. Convenient drug handling and limited side effects are key points in ensuring patient compliance. The study of the extended wearing time has resulted in the registration of the patch for a duration of application of up to 4 days (96 hours) allowing regular patch changes on 2 fixed days a week (Likar 2005), which is easier to remember for elderly patients and carers. In the post-marketing surveillance study, patient compliance at the end of the observation period was 91%. The fact that 70% of the patients continued with buprenorphine TDS after completion of the study indicates that it is not only effective, but also easy and convenient to use (Griessinger et al 2005). 123