The aim was to study the side-effect profile and the survival characteristics of leflunomide used in a regional patient population in New Zealand (NZ).
  Patients were identified using special authority forms (SAFs) that had been prospectively filed from January 2001 to June 2007. Statistical analysis of survival data was done using the Kaplan-Meier (KM) method.
Of 110 patients identified on SAFs, only 90 were suitable for analysis. The percentage of women and men were 74% and 26%, respectively. Their mean age was 55.58 years ± 13.44. Their diagnoses were rheumatoid arthritis 75%, psoriatic arthritis 15%, others 10%. Their mean disease duration was 11.31 years ± 8.93. The mean number of concomitant disease-modifying antirheumatic drugs used was 1.95. These were methotrexate (MTX) in 48, hydroxychloroquine in 29, prednisone in 30 and sulfasalazine in 27. Thirty-two of 90 (35.5%) discontinued treatment, 12 (13.3%) of these were in the first 6 months. The mean time to discontinuation was 14.2 months. Twenty-three of 32 discontinuations were for side-effects. The incidence of side-effects were similar to those of an earlier 2-year NZ study, and better than other earlier studies. Leflunomide survival using the KM method at 5 years was 57%, higher than suggested by previous leflunomide studies and this compares well with MTX studies.
Our study suggests a better side-effect profile and a better drug survival for leflunomide than suggested by previous studies with survival comparable to that of MTX.