Brief Answer: No. Clinically not significant. Detailed Answer: Hello, As you explained, it was considered that Doxycycline may slow down the progression of Osteoarthritis in 2005. ( Reference: Randomized, double-blind trial published in the July, 2005 issue of Arthritis and Rheumatism). Recent study published in 2009 says Compared to placebo, there is minimal or no symptomatic benefit (pain reduction and improved physical function) with doxycycline treatment. The small benefit observed in joint space narrowing is of questionable clinical relevance and outweighed by safety issues. Doxycycline should therefore not be recommended for the treatment of osteoarthritis of the knee or hip. ( Reference: Nuesch E et al. Doxycycline for osteoarthritis of the knee or hip. Cochrane Reviews 2009, Issue 4. Article No. CD007323. DOI: 10.1002/0000.CD007323.pub2.) Recent study in 2011 concludes that "Doxycycline is not effective in reducing symptoms in knee osteoarthritis patients over a 24-week study period, but is associated with an increased risk of adverse events. Although a possible structure-modifying effect of doxycycline was previously suggested, this is not accompanied by symptom relief in the short and medium term." ( Reference: Randomized controlled trial published in the July, 2011 issue of the Annals of the Rheumatic Diseases by Gijs F. Snijders, MD, from Sint Maartenskliniek, Department of Rheumatology, Nijmegen, the Netherlands, and colleagues). Thus Even though Doxycycline may show joint space narrowing which is of questionable clinical relevance. doxycycline will not result in clinically important improvement of joint pain or Physical function.

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