Women are at higher risk than men for diuretic-induced hyponatremia resulting in hospital admission, according to a recent study published in Pharmacoepidemiology & Drug Safety.

In a case-control study that included 886,935 diuretic users (524,683 women and 362,252 men) in The Netherlands, investigators found that women had significant 2.7-fold higher odds of hospitalization due to diuretic-induced hyponatremia compared with men after adjusting for potential confounders. The higher risk for women vs men was present regardless of diuretic type.

“The underlying mechanism that could cause the higher risk of hyponatremia in women using diuretics is not fully understood,” Linda C. Hendriksen of Erasmus University Medical Center in Rotterdam, and colleagues wrote. “There might be sex differences in vasopressin regulation and in the amount and activity of several receptors and transporters.”

Hendriksen and colleagues used 2005 to 2017 data from the PHARMO Data Network, which is a population-based network of electronic health care databases for the study. Of the cohort, 1257 women and 332 men had a first hospital admission for hyponatremia from January 1, 2005 to December 31, 2017. The investigators matched these patients to a control group of 10,639 women and 5223 men who used diuretics but were not hospitalized with hyponatremia.

Strengths of the study included the use of a large population-based database and the availability of individual patient data on hospital admissions and drug dispensing, the authors noted. “With this information, we were able to adjust for age, number of diuretics and other hyponatremia-inducing drugs, chronic disease score, daily dose and the duration of use of the diuretic, factors that have not previously been studied in hyponatremia-related hospital admissions.”

The investigators pointed out, however, that they had limited availability of other possible confounders. In addition, patients’ sodium levels were not available. “Patients with a low sodium level could have been missed when hyponatremia was not documented by the physician or not coded at discharge.”

Reference

Hendriksen LC, van der Linden PD, Herings RMC, Stricker BH, Visser LE. Women on diuretics have a higher risk of hospital admission because of hyponatremia than men. Pharmacoepidemiol Drug Saf. 2023:1-8. Published online January 12, 2023. doi:10.1002/pds.5592

HealthDay News — For patients receiving thiazide diuretics, the occurrence of major cardiovascular outcome events or non-cancer-related deaths is no lower for those receiving chlorthalidone vs those receiving hydrochlorothiazide, according to a study published in the December 29 issue of the New England Journal of Medicine.

Areef Ishani, MD, from the University of Minnesota in Minneapolis, and colleagues randomly assigned 13,523 adults aged 65 years or older who had been receiving hydrochlorothiazide at 25 or 50mg/day to continue therapy with hydrochlorothiazide or to switch to chlorthalidone at a daily dose of 12.5 or 25mg (675 and 702 patients, respectively). At baseline, 12,781 of the patients (94.5%) had been prescribed hydrochlorothiazide at a dose of 25mg/day.

The researchers observed little difference in the occurrence of primary outcome events (nonfatal myocardial infarction, stroke, heart failure resulting in hospitalization, urgent coronary revascularization for unstable angina, and non-cancer-related death) between the chlorthalidone group and the hydrochlorothiazide group (10.4 vs 10.0%). No between-group differences were seen in the occurrence of any of the components of the primary outcome. The chlorthalidone group had a higher incidence of hypokalemia than the hydrochlorothiazide group (6.0 vs 4.4%).

“Chlorthalidone did not lead to a lower incidence of major cardiovascular outcomes or non–cancer-related deaths than hydrochlorothiazide at doses commonly used in clinical practice,” the authors write.

One author disclosed financial ties to ReCor Medical.

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