Peripheral neuropathy in patients on leflunomide

Sir, Much progress has been made in understanding the pathogenesis of rheumatoid arthritis. This has resulted in the development of novel therapeutic strategies. Leflunomide is a disease-modifying anti-rheumatic drug (DMARD) which is in vogue all over the world. The active metabolite of leflunomide, A77 1726, reversibly inhibits dihydroorotate dehydrogenase (DHODH), the rate-limiting step in the de novo synthesis of pyrimidines [1]. The side-effects so far reported in trials are gastrointestinal intolerance, elevation of liver enzymes, mild allergic reactions, reversible alopecia and hypertension [2]. Peripheral neuropathy has not been reported so far in these studies with leflunomide. Our immunology–rheumatology clinic is part of a tertiary care centre in southern India. One hundred and fifty patients with rheumatoid arthritis (ACR criteria) attending our clinic between October 2000 and March 2003 formed the study cohort. All patients were given single or combination DMARDs. Patients who were already on DMARDs and those with confounding factors for neuropathy were excluded from the study. Patients were followed up at 1 month and then 2-monthly. A thorough clinical examination was done for any side-effects, and haemogram, liver function and renal function tests were obtained at each visit.