Patients with moderate to severe pain were treated with buprenorphine patches in one of 3 concentrations: 35 micrograms/h, 52.5 micrograms/h and 70 micrograms/h (= 0.8 mg/d, 1.2 mg/d and 1.6 mg/d respectively). The aim of this review was to assess the efficacy and tolerability of this transdermal system (TDS) in patients with chronic pain. A total of 445 patients were included in 3 double-blinded studies. The dosage titration with buprenorphine patches followed pretreatment with buprenorphine sublingual tablets, higher doses of weak opioids (level 2 substances), low dose morphine (level 3) or other analgesics. Patients with chronic tumour or non-tumour pain were recruited for these studies and treated with buprenorphine patches or placebo for 6 to 15 days. All patients were offered, in addition, buprenorphine sublingual tablets to be taken as required for supplementary pain relief. Pain intensity, analgesia, consumption of buprenorphine sublingual tablets and sleep duration were all assessed. All patients in the double-blinded studies were between the ages of 22 and 88. 249 patients suffered from tumour pain and 196 patients suffered from non-tumour pain. To examine long-term efficacy and tolerability of the transdermal system, treatment was expanded, if the patients were interested in participating in an open-label-study. In all 3 studies, the number of patients with moderate, severe and very severe pain increased in the placebo-patch treated group, while the patients in the buprenorphine transdermal system treated group had a greater incidence of mild or no pain. A further benefit in the buprenorphine transdermal system treated group was evidenced by a great number of patients with a daily sleep duration of more than 6 hours compared to the placebo group--an indicator of greater well-being. The systemic side-effects were typically opioid in nature and rare and usually only mild. Of particular note was the very low incidence of constipation in only 5.3% of cases. Dermatological reactions to the patches were only rarely encountered. The dermatological reactions consisted mainly of erythema and pruritus with a mild to moderate extent. Half the cases of erythema and more than on third of the cases of pruritus were spontaneously reversible. More than half the patients (53.7%) in the double blind studies wished to continued treatment with buprenorphine transdermal system. These results demonstrate that buprenorphine patches achieved a very good analgesic effect in all 3 studies and that in particular with respect to the quality of life of the patient these patches offer an exceptional alternative to other conventional therapies.