5692 Musings

Oral or Transdermal Opioids for Osteoarthritis of the knee or hip, Cochrane data base systemic review 2014 September Da Costa B R et al.

This Cochrane review looked at 22 trials with over 8000 participants. Fourteen of the trials involved pure mu opioids with eight of the trials involving transdermal Buprenorphine and oral Tapentadol. The meta-analysis results showed that opioids produced a reduction of 0.7cm on a 10cm visual analogue scale for pain between opioids and placebo, corresponding to a difference in improvement of 12% between opioids and placebo which translated into a number needed to treat to cause one additional treatment response of 10 to cause one additional treatment response. For function, opioids produced 0.6 unit improvement on the WOMAC leading to a difference of 11% and a number needed to treat of 11. 22% of opioid participants experienced side effects vs. 15% of placebo patients. The authors’ conclusions were that opioids produced questionable clinical relevance since the 95% confident intervals for pain reduction did not include a minimally clinically important difference of 0.9cm on a 10cm visual analogue scale for pain.

Comment: Unfortunately, this meta-analysis shows the very limited clinical benefit across the board for opioids in osteoarthritis of the knee or hip. Obviously, there will be some small subgroups that will benefit significantly and that it will be combined with a large majority of patients who benefit not at all. Whilst this does not mean that opioids should not be trialled for patients with osteoarthritis of the knee or hip, it certainly means that patients should not continue with opioid therapy unless dramatic sustained improvements in pain reduction and function actually occur. Certainly, one would consider opioids for osteoarthritis of the knee or hip as second or third line therapy.