Hydroxychloroquine sulfate in rheumatoid arthritis: long-term response rate and predictive parameters.

Review of the records of 108 patients with rheumatoid arthritis who were treated with hydroxychloroquine sulfate for at least six months revealed that 63 percent responded: 12 percent achieved complete remission (no joint pain or tenderness, two or less joints with trace swelling); 14 percent showed a 75 percent response (75 percent or greater reduction in active joint count and 50 percent or greater reduction in morning stiffness); and 37 percent had between 30 percent (30 percent or greater reduction in active joint count and morning stiffness) and 75 percent response. Once response was obtained, flare-up of rheumatoid arthritis was uncommon. Only two of 108 patients developed retinopathy (subclinical); it resolved with drug discontinuation and did not cause visual deficits. Better grip strength and radiographs showing little articular damage at baseline might predict response to treatment with hydroxychloroquine. However, even though early disease may be more responsive, long-term rheumatoid arthritis does not preclude a good response to hydroxychloroquine.