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Evidence summaries

Doxycycline for Osteoarthritis of the Knee or Hip

Doxycycline appears not to be effective for the treatment of osteoarthritis of the knee or hip. Level of evidence: "B"

A Cochrane review [Abstract] 1 included 2 studies with a total of 663 subjects. The first study randomized 431 obese women with radiologically confirmed osteoarthritis of the knee to receive doxycycline 100 mg or placebo twice a day for 30 months. The other study included women and men with radiologically confirmed osteoarthritis of the knee, who were randomly allocated to receive doxycycline 100 mg or placebo twice a day for 24 weeks.

At end of treatment, clinical outcomes were similar between the two treatment groups (Table T1). More patients withdrew from the doxycycline group (39/1000) compared with placebo (17/1000) due to adverse events (RR 2.28, 95% CI 1.06 to 4.90; 2 studies, n=663). Number needed to harm (NNTH) was 46 (95% CI 15 to 980). There was no evidence that participants in the doxycycline group experienced more serious adverse events than those in the placebo group, but the estimate was imprecise (RR 1.07, 95% CI 0.68 to 1.68; 2 studies, n=663).

Doxycycline compared with placebo for osteoarthritis of the knee or hip.

OutcomeNumber of participants (studies)Assumed change (placebo)Corresponding change (doxycycline)Difference between doxycycline and placebo (95% CI)
Decrease in pain (10-cm VAS scale);median follow-up 18 months524 (2)1.8 cm decrease in pain pain on 10-cm VAS1.9 cm decrease in pain on 10-cm VASΔ-0.1 cm (-0.6 to +0.3 cm) favouring doxycycline
29% improvement32% improvementΔ3% (-5% to 10%)
Function (WOMAC function, range 0 to 10);median follow-up 18 months517 (2)1.2 units improvement on WOMAC1.4 units improvement on WOMACΔ-0.2 ( -0.5 to +0.2) favouring doxycycline
21% improvement24% improvementΔ3% (-3% to 10%)
Changes in minimum joint space narrowing;follow-up 30 months361 (1)0.45 mm change0.30 mm changeΔ-0.15 mm ( -0.28 to -0.02 mm) favouring doxycycline

Comment: The quality of evidence is downgraded by study limitations (unclear allocation concealment and failure to adhere to the intention-to-treat principle).

    References

    • da Costa BR, Nüesch E, Reichenbach S et al. Doxycycline for osteoarthritis of the knee or hip. Cochrane Database Syst Rev 2012;(11):CD007323. [PubMed].

Primary/Secondary Keywords