What is the evidence for doxycycline therapy in the treatment of osteoarthritis of the knee?
AMSTAR Rating
Summary
Patient Population:
2 trials – both enrolled participants with OA of the knee. One trial (n=431) enrolled only obese women – the other (n=232) enrolled both men and women. In both studies, participants could take other pain medicine; however, in one study, opiods were limited to tramadol.
Intervention:
100 mg doxycycline BID for 24-30 weeks.
Comparison:
Treatment was compared to placebo. 12 reports were identified for inclusion. However, these reports described 2 randomized controlled trials. One of the two trials could be considered high quality.
Outcome:
- Pain: doxycycline vs. placebo – non-significant difference in favour of doxycycline (ES=-0.05; 95% CI -0.22 to 0.13, n=524).
- Function: doxycycline vs. placebo – non-significant difference in favour of doxycycline (ES -0.07; 95% CI -0.25 to 0.1, n=517).
- Safety: Assignment to the treatment condition was associated with increased risk for an adverse event reported over a period of 6 months (RR= 1.36 (1.08 to 1.72; n=232; GRADE rating = low).
- Safety: Assignment to treatment with doxycycline therapy was associated with an increased risk for withdrawal due to adverse events (RR= 2.28, 95% CI = 1.06 to 4.90; n=663; GRADE rating = low).
