Buprenorphine is a highly lipophilic thebaine derivative that appears to have high affinity for mu-, kappa-, and delta-opioid receptors and low affinity for opioid receptors like 1 -receptors. It acts as a partial agonist at the mu-opioid and as a partial agonist/antagonist at the kappa-opioid, and as an antagonist at the delta opioid receptors. Buprenorphine has up to two-fold duration of action and it is approximately 30-fold more potent when compared to morphine.

Pain is a common problem in patients coming to joint arthroplastic surgery. Buprenorphine low dose patches are recommended for treatment of moderate pain for example osteoarthritis pain. It is known that well treated pain even preoperatively may prevent prolonged postsurgical pain.

In the present study the effects of low dose buprenorphine on postoperative pain and recovery were assessed.

Inclusion Criteria:

• no pregnancy/lactation, reliable contraception before menopause
• elective knee or hip arthroplasty surgery
• BMI (=body mass index) 18-35 kg/m2
• obtained informed consent

Exclusion Criteria:

• buprenorphine medication

• allergy to study drugs• ikä < 18 tai >75 years

  • BMI <18 tai>35 kg/m2
  • weight below 50 kg
  • Other contraindication for the study drug