Is buprenorphine transdermal patch equally safe and effective in younger and elderly patients with osteoarthritis-related pain? Results of an age-group controlled study.

OBJECTIVE

A recent pharmacokinetic study with buprenorphine transdermal patches showed similar systemic exposures of buprenorphine in subjects aged ≥75 and 50-60 years. The current prospective, open-label study aimed to verify this in a clinical setting by evaluating efficacy and safety of buprenorphine patches in patients with chronic osteoarthritis (OA) pain.

METHODS

Patients with chronic, moderate to severe osteoarthritic pain (hip and/or knee) were enrolled: 50-60 years (younger group, N = 65) and ≥75 years (elderly group, N = 57). After 2 weeks on paracetamol only, patients received buprenorphine patches (5-40 µg/h) for 12 weeks. Paracetamol rescue was provided. Primary endpoint was the Box-Scale-11 (BS-11) score for pain on average over the last week. WOMAC OA Index, EQ-5D, Patients' and Investigators' Global Assessment of Pain Relief, rescue medication use, sleep disturbance and quality of sleep were secondary efficacy endpoints.

RESULTS

Both groups showed a statistically significant (p < 0.0001) and clinically relevant change from baseline to last visit in BS-11 score, with no significant difference between groups. The least squares (LS) mean change from baseline was 2.20 in elderly and 1.87 in younger patients, with an age group difference of 0.33 (95% CI: -0.42, 1.07). Non-inferiority of the elderly versus the younger group was shown. Both age groups showed a significant improvement in WOMAC total score, patients' overall health state (EQ-5D visual analogue scale) and sleep quality, and a significant reduction in rescue use and nights woken due to pain, with no significant differences between groups. Elderly patients tolerated buprenorphine patches at least as well as younger patients.

CONCLUSIONS

Efficacy and tolerability of buprenorphine patches was demonstrated in chronic pain patients, regardless of age, supporting the conclusion that no age-related dose adjustment of transdermal buprenorphine is needed. A study limitation is lack of active control but no other opioid was appropriate in elderly patients or this indication.