Doxycycline and OA Progression

Exclusion Criteria

• •Premenopausal status (unless subject has had a hysterectomy).
• •Current use of any investigational drug.
• •Significant hematologic, renal, hepatic or cardiovascular disease (but not including mild/moderate hypertension) or any other serious medical condition that might preclude the subject's ability to participate fully in the project, keep clinic appointments, etc.
• •Prior surgery (including arthroscopy) of the contralateral knee.
• •Significantly abnormal laboratory values at the time of enrollment.
• •Pigmented villonodular synovitis of the knee.
• •Synovial chondromatosis.
• •Charcot arthropathy.
• •A known "secondary" cause of OA, including acute or chronic infectious OA; crystal-induced arthritis; systemic inflammatory connective tissue disease (e.g., rheumatoid arthritis, systemic lupus erythematosus); osteonecrosis; Paget's disease; or metabolic diseases, such as hemochromatosis, Wilson's disease, or ochronosis. Chondrocalcinosis, however, will not be an exclusion criterion.
• •Conditions other than knee OA which limit lower extremity function and mobility and/or would confound the evaluation of knee pain and function (e.g., clinically significant spinal or hip arthritis, painful or dysfunctional feet, peripheral vascular disease, lumbar radiculopathy, stroke, etc.).
• •Steroid injection into either knee within past 3 months.
• •A history of photosensitivity (sensitivity to light) or any other adverse reaction to a tetracycline.
• •Failure to pass a "faintness-of-heart" test (pre-randomization compliance test).
• •Prior chronic use of tetracycline (e.g., for severe acne).
• •Severe OA (Kellgren and Lawrence Grade IV) of the index knee.
• •Salicylate use, with a mean dose \>2g/d.
• •Institutionalization.