Continuous diuretic use averts hyponatraemia hospitalization

Patients with ongoing use of furosemide are at decreased risk of being hospitalized due to hyponatraemia, according to a study, suggesting that this type of diuretic may have a protective effect.

Diuretics have been linked to hyponatraemia, and the study sought to investigate whether this association vary by types of nonthiazide diuretics. Researchers looked at a total of 11,213 patients hospitalized with a principal diagnosis of hyponatraemia and 44,801 matched controls.

Logistic regression was used to evaluate potential associations, with adjustments for multiple confounders. The analysis was also stratified according to thiazide use (newly initiated [≤90 days] and ongoing use).

The risk of hospitalization for hyponatraemia had a positive association with amiloride use (adjusted odds ratio [aOR], 1.69, 95 percent confidence interval [CI], 1.54–1.86) and spironolactone use (aOR, 1.96, 95 percent CI, 1.78–2.18), as well as an inverse association with furosemide (aOR, 0.61, 95 percent CI, 0.57–0.66).

The protective association with furosemide, specifically, was seen for ongoing use (aOR, 0.52, 95 percent CI, 0.47–0.57) but not for newly initiated therapy (aOR, 1.23, 95 percent CI, 1.04–1.47).

Risk estimates associated with other drugs as stratified by use were as follows: 3.55 (95 percent CI, 2.75–4.61) for newly initiated spironolactone, 1.75 (95 percent CI, 1.56–1.98) for ongoing spironolactone use, and 1.62 (95 percent CI, 1.47–1.79) for ongoing amiloride use.

The results indicate that while furosemide may be protective against hyponatremia, spironolactone and amiloride may both contribute to it, with this effect being most prominent early in treatment.