Controlled trial with chloroquine diphosphate in systemic lupus erythematosus

Antimalarials have been recognized as effective drugs for the treatment of articular and cutaneous manifestations of systemic lupus erythematosus (SLE), but its potential in the management of systemic features of the disease has not yet been thoroughly evaluated.

This study intended to evaluate the efficacy of chloroquine diphosphate (CDP) in preventing flares and in reducing the maintenance corticosteroid dose in patients with SLE without life-threatening manifestations.

Twenty-four SLE patients with no life-threatening manifestation were enrolled in a 12-month double blind placebo-controlled trial with CDP (250 mg/day). Patients were subjected each month to clinical examination by a rheumatologist and to SLE-relevant laboratory tests. At each visit, prednisone dose could be adjusted according to the clinical status. Ophthalmologic examination was performed every six months. Outcome measures included SLEDAI score and the required prednisone dose. SLE flare was defined as an increase in SLEDAI score of at least three points. Prednisone dose reduction was defined as a minimum 50% dose decrease with no concomitant disease flare.

Twenty-three patients completed the study. One patient in the placebo (PL) group dropped out due to severe dyspepsia. No major side-effect was observed in the remaining patients. PL and CDP groups showed no significant difference at the beginning of the study with regard to sex, age, ethnic classification, disease duration, SLEDAI and prednisone dose. Along the trial the prednisone dose became progressively lower in CDP group as compared to PL group and the difference reached statistical significance at 4, 6 and 12 months. SLEDAI score was higher in PL group in all evaluations, being the difference statistically significant at 4 months. Flare-up episodes were registered in two patients in CDP group and in ten patients in PL group. The estimated reactivation risk was 4.6 times greater in PL group as compared to CDP group.

CDP at a 250 mg/day dose was able to prevent disease exacerbation, reduce the required prednisone dose, and help inducing a better control of patients with non life-threatening SLE. These data suggest that antimalarials might have a broader indication in the treatment of SLE other than solely the management of skin and articular manifestations.