Leflunomide in active rheumatoid arthritis: A prospective study in daily practice

Abstract

Aims: We prospectively studied the efficacy, incidence of adverse drug reactions and withdrawal from leflunomide in an outpatient population with rheumatoid arthritis in a setting of care-as-usual. Methods: In this prospective case series study, a standard dataset was collected from outpatient medical records, including patient and disease characteristics, data on leflunomide use and adverse drug reactions. Results: During the study period 136 rheumatoid arthritis patients started leflunomide. Median (range) follow-up duration was 317 (11-911) days. Sixty-five percent of patients experienced at least one adverse drug reaction related to leflunomide. During followup 76 patients (56%) withdrew from leflunomide treatment, mainly because of adverse drug reactions (29%) or lack of efficacy (13%). The overall incidence density for withdrawal from leflunomide was 56.2 per 100 patient years. Complete data for calculating efficacy using a validated disease activity score on 28 joints (DAS 28) was available for 48, 36, and 35% of patients at 2, 6, and 12 months follow-up, respectively. Within a 12-month period after start of leflunomide treatment 76% of the evaluable patients were classified as moderate or good responders according to the DAS28 response criteria. Conclusions: In the setting of care-as-usual rheumatoid arthritis patients starting leflunomide frequently experienced adverse drug reactions. More than half of the patients withdrew from leflunomide treatment within 1 year of starting leflunomide treatment, mainly because of adverse drug reactions.