Assessment of analgesic effects of different initial doses of transdermal buprenorphine in the treatment of chronic pain in the elderly diagnosed with osteoarthritis.

Abstract

The aim of the study was to evaluate analgesia, adverse effects, and quality of life of elderly patients diagnosed with osteoarthritis during treatment with different initial doses of transdermal buprenorphine. Transdermal buprenorphine was used for 10 days in 60 patients over 64 years old with chronic pain of severe intensity - Numerical Rating Scale (NRS > 5) caused by degenerative changes in joints. All patients were randomly assigned to 3 groups. A starting dose for the treatment was respectively: 8.75 μg/h, 17.5 μg/h or 35 μg/h, in each group. The severity and impact of pain on everyday activities performed by the patients were assessed at baseline and daily for 10 days using the Brief Pain Inventory - Short Form. In order to identify the components of neuropathic pain, except for the symptoms (hyperalgesia and allodynia), the DN4 (Douleur Neuropathique en 4 questionnaire) was used. During buprenorphine treatment a decrease in pain severity was obtained in all groups of patients as well as an improvement in pain interference with general activity, mood, walking ability, relations with other people, sleep and enjoyment of life with no differences between patient groups treated with different initial doses of transdermal buprenorphine. No differences regarding DN4 scores were find between patient groups. Several adverse effects (drowsiness, confusion, vomiting) occurred less frequently in groups of patients treated with lower initial doses (8.75 μg/h and 17.5 μg/h) in comparison to a starting dose of 35 μg/h. We concluded that treatment of elderly patients with chronic pain of severe intensity with transdermal buprenorphine provided effective analgesia and improvement of quality of life with respect to general functioning of patients. Treatment tolerance seemed to be better with lower initial doses of transdermal buprenorphine: 8.75 μg/h and 17.5 μg/h in comparison with the dose of 35 μg/h.