A prospective analysis of risk factors for the discontinuation of second-line antirheumatic drugs

Clinical and laboratory factors influencing the discontinuation of second-line antirheumatic drugs were prospectively studied using survival analysis in a consecutive series of 245 patients with recently diagnosed rheumatoid arthritis. A statistically significant influence of age, sex, serum IgA and HLA-DR3 on the discontinuation rate of chrysotherapy because of toxicity was observed. The discontinuation of sulfasalazine was increased by advanced age and high rank order of prescription. With respect to efficacy, high initial disease activity appeared to predispose to treatment termination of hydroxychloroquine, sulfasalazine and penicillamine. Furthermore, an influence of the rank order of prescription on discontinuation of sulfasalazine therapy because of lack of efficacy was found. Of interest is that discontinuation of hydroxychloroquine therapy because of lack of efficacy occurred less frequently in HLA-DR3-positive than in HLA-DR3-negative patients. Although these prognostic factors are of secondary importance in clinical practice, they may be of significance in the interpretation and comparison of clinical trials.