The aim of this study was to evaluate the efficacy and safety of leflunomide in patients with active rheumatoid arthritis (RA).
The study included 100 patients (88 women and 12 men) with rheumatoid arthritis (RA). The mean age was 46.5 years and the mean duration of the disease was 10.3 years. The inclusion criteria were a Disease Activity Score (DAS28) of over 3.2, and contraindications to methotrexate or failure of treatment with methotrexate for at least 3 months. The patients that were enrolled in the study had developed lesions of various grades according to the Steinbrocker Radiological Classification. Leflunomide was administered at a dose of 20 mg per day for the whole observation period. During the monitoring appointments the duration of morning stiffness, pain and disease activity were evaluated on a visual analogue scale (VAS), as well as the number of tender and swollen joints and the DAS28 score. In compliance with the leflunomide therapy protocol, the following control tests were performed: erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), hematology, creatinine and liver function tests. Safety assessment included monitoring of adverse events and laboratory test results.
During the one-year monitoring period significant improvements were noted in 68% of the patients, expressed as a decrease of 1.2 or more in their DAS28 scores. DAS28 > 0 < 1.2 was achieved in a further 18% of the patients. No improvement was reported by 14% of the subjects. In one year of treatment leflunomide was effective in 74% of the patients with active RA. The most marked clinical improvement in the DAS28 index was noted between the third and sixth months of treatment. In the next six months ESR, CRP and DAS28 scores continued to decline steadily, but the differences were not as clear as those recorded in the previous time period.
The most commonly observed adverse events were related to the gastrointestinal tract (i.e. diarrhea and periodic increases in liver function tests), and reported hair loss. Mild to moderate adverse events were observed in 19% of the patients; they resolved spontaneously or in response to medication, and were not a reason for discontinuing therapy in any of the cases.