Original articleSafety of furosemide administration in an elderly woman recovered from thiazide-induced hyponatremia
Introduction
Hyponatremia is a well known complication of diuretic therapy [1]. In most instances, the offending drugs have been thiazides or related molecules [2] which induced both sodium depletion and inappropriate water retention.
Indeed, contraction of extracellular compartment secondary to diuretics induced volume depletion decreases fluid delivery to the diluting segment of the nephron and increases water reabsorption due to the stimulation of vasopressin release by non-osmotic stimuli ; both factors are responsible for a decrease in free water excretion, increasing the risk for the development of hyponatremia. Interestingly, furosemide, which is a more potent natriuretic drug has been only exceptionally involved in diuretic-induced hyponatremia [2], [3]. All these data suggest that the intrinsic molecular properties of the thiazide diuretics and related molecules may be directly instrumental in the occurrence of hyponatremia at least in part though an increase of the permeability to water of the collecting tubule as reported for indapamide [2]. Conversely specific properties of loop diuretic may protect for the development of hypoosmolar syndromes as exemplified by their use in the treatment of inappropriate antidiuresis [4]. We thus hypothesized that furosemide could be a safer diuretic in patients with an history of thiazide-induced hyponatremia. In the present study, we prospectively compare the effects of furosemide and AmHTZ on renal water excretion in one patient recovered from a hyponatremic episode related to AmHTZ treatment.
Section snippets
Case report
A 79-year-old woman was admitted with anorexia, nausea, and recent loss of memory. Her past medical history included systolic hypertension treated with one AmHTZ tablet a day, during the 5 days preceding the hospitalization. On admission, she was stuporous; physical examination was otherwise normal. Pertinent initial serum blood values were as follow: urea 57 mg/dl; creatinine 0.80 mg/dl; K+ 4.5 mEq/L; Na+ 119 mEq/L; Cl− 77 mEq/L; HCO3− 23 mEq/L; blood and urine osmolality were respectively 242
Evolution of SNa+ (Fig. 1)
After recovering, the patient was on a free water intake averaging 1830 mL a day, during the whole admission period. SNa remained above 135 mEq/L during that period even after the first water loading test. After AmHTZ administration followed by the second water load, serum Na+ falls significantly from 133 to 128 mEq/L. In contrast during administration of furosemide, no significant decrease in serum Na+ was noted. During the first 3 days, serum potassium fluctuated between 4.5 mEq/L and
Discussion
Elderly hypertensive women are at risk to develop severe hyponatremia when treated by thiazide diuretics or related molecules [1], [2], [11]. Although several pathogenic mechanisms responsible for the occurrence of hyponatremia have been proposed, inappropriate water retention appears to be the major pathogenic factor as suggested by Friedman et al [12]. Arguments favoring the role of a thiazide-induced decrease in urinary diluting capacity as the major cause of hyponatremia are the positive
Learning points
- •
The occurrence of hyponatremia after thiazide administration identifies patients at risk for recurrent hyponatremic episodes after rechallenge with the offending drug
- •
If confirmed by larger studies, Furosemide would be a safest diuretic alternative for patients with a previous thiazide-induced hyponatremic episode
- •
Evaluating the ability to electrolyte free water by a standard oral water loading test performed during thiazide rechallenge helps to predict the occurrence of future hyponatremia.
References (15)
- et al.
Diuretic-induced severe hyponatremia. Review and analysis of 129 reported patients
Chest
(1993) - et al.
Natriuresis and atrial natriuretic factor secretion during inappropriate antidiuresis
Am J Med
(1988) - et al.
Evolving concepts in the quantitative analysis of the determinants of the plasma water sodium concentration and the pathophysiology and treatment of the dysnatremias
Kidney Int
(2005) - et al.
Total body water reference values and prediction equations for adults
Kidney Int
(2001) - et al.
Total body water volumes for adult males and females estimated from simple anthropometric measurements
Am J Clin Nutr
(1980) - et al.
Diuretic-induced hyponatraemia in elderly hypertensive women
Lancet
(1983) - et al.
Diuretic-induced hyponatremia
Ann Intern Med
(1971)
Cited by (16)
Diuretics in Hypertension
2018, Hypertension: A Companion to Braunwald's Heart DiseaseHyponatremia
2013, Seldin and Geibisch's The KidneyHyponatremia
2012, Seldin and Giebisch's The Kidney: Physiology and PathophysiologyDiuretic Therapy in Cardiovascular Disease
2013, Hypertension: A Companion to Braunwald's Heart Disease: Second EditionDifficulties in treatment with thiazide in the elderly
2023, Arterial Hypertension (Poland)Hyponatremia-inducing drugs
2019, Frontiers of Hormone Research