Interaction Between Warfarin and Ethacrynic Acid

HAZARDOUS conditions may result from interactions of drugs that can substantially increase or decrease a patient's response to warfarin sodium. The interaction between warfarin and ethacrynic acid has been demonstrated in vitro, but apparently, no clinical evidence has been reported in the literature confirming this. We have had the opportunity to observe a patient taking both warfarin and ethacrynic acid. Report of a Case A 38-year-old woman was admitted with known primary pulmonary hypertension diagnosed by cardiac catheterization. As on multiple prior admissions, she had weight gain, shortness of breath, chest discomfort, and belching. She had a two-year history of labile hypertension. During 1972, she developed increased skin pigmentation, elevated blood pressure, and cor pulmonale. Since then, severe failure of the right side of the heart has required several admissions and therapy with extremely high doses of diuretics. A diagnosis of protein-losing enteropathy with hypoalbuminemia was established. Recently, paroxysmal nocturnal