A treatment resistant hypokalemia case associated with leflunomide

Abstract

Introduction: Leflunomide is a disease-modifying antirheumatic drug which is used in the treatment of rheumatoid arthritis. The most common side effect of leflunomide is diarrhea, however, hypokalemia may also develop during treatment with this drug. Here, we present a case with treatment resistant hypokalemia in a patient who has been on leflunomide treatment for approximately 8 weeks for treatment of rheumatoid arthritis.

Case report: Fifty six years old woman was admitted to internal medicine outpatient clinic with complaints of weakness, constipation, loss of appetite, abnormal weight loss (approximately 10 kilograms) and arthralgias for 3 weeks. Laboratory analyse revealed hypokalemia on admission (serum potassium: 2.3 mmol/L). Potassium chloride was infused in isotonic solutions with close monitoring; a potassium value of 4.5 mmol/L was achieved on the fifth day of treatment. Her complaints such as nausea, constipation, lack of appetite were decreased with normalization of serum potassium.

Conclusion: We suggest close electrolyte monitoring is important if leflunomide treatment was planning especially in patients whose treatment regimens include multiple medications.