Combination Therapy of Angiotensin II Receptor Blocker and Thiazide Produces Severe Hyponatremia in Elderly Hypertensive Subjects

• Published in: Internal Medicine Vol. 53; no. 7; pp. 749 - 752
• Main Authors: Yoshida, Masashi, Asano, Tomoko, Ishikawa, San-e, Kusaka, Ikuyo, Aoki, Atsushi, Yamada, Hodaka, Ikoma, Aki, Kawakami, Masanobu, Kakei, Masafumi
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society of Internal Medicine 01.01.2014
• Subjects: Aged; Aged, 80 and over; Angiotensin II Type 1 Receptor Blockers - adverse effects; Angiotensin II Type 1 Receptor Blockers - therapeutic use; arginine vasopressin; Drug Therapy, Combination - adverse effects; elderly subjects; Humans; Hypertension - drug therapy; Hypertension - physiopathology; hyponatremia; Hyponatremia - blood; Hyponatremia - chemically induced; Male; Severity of Illness Index; Sodium - blood; Sodium - urine; Sodium Chloride Symporter Inhibitors - adverse effects; Sodium Chloride Symporter Inhibitors - therapeutic use; thiazide diuretics
• ISSN: 0918-2918; 1349-7235; 1349-7235
• DOI: 10.2169/internalmedicine.53.1738

Thiazide diuretics are known to produce severe hyponatremia as well as hypokalemia. The present study demonstrated severe hyponatremia in three hypertensive patients who had received combination therapy consisting of an angiotensin II receptor blocker (ARB) and thiazide. The serum sodium (Na) levels in all three cases were markedly reduced to below 116 mmol/L, and the patients exhibited augmented urinary excretion of Na with a reduced circulatory blood volume. After withdrawing the ARB and thiazide treatment, the serum Na levels normalized within one to two weeks. Combination therapy with ARBs and thiazide may cause hyponatremia in elderly patients.