Probable boceprevir-induced hyponatremia in a patient with chronic hepatitis C.

Purpose: A probable case of severe drug-induced hyponatremia associated with boceprevir use is reported.

Summary: A 55-year-old woman was started on boceprevir (800 mg orally thrice daily) during week 5 of triple therapy for chronic hepatitis C. Her serum sodium concentration the morning before starting boceprevir use was 140 mmol/L.