A patient with long-standing hypertension developed urticaria, angioedema, and hypotension within 5 minutes after the intravenous administration of furosemide. Immediate hypersensitivity was documented by positive skin tests to furosemide as well as to related sulfonamide-based drugs. This is the first finding of an anaphylactic reaction to furosemide and underscores the need to consider such adverse reactions when patients who are sensitive to other sulfonamide-containing drugs are being treated. © 1987.
