Development of a hyponatremia screening tool (ABCDF-S score) for patients with hypertension using thiazide diuretic agents

Risk of Electrolyte Disorders, Syncope, and Falls in Patients Taking Thiazide Diuretics: Results of a Cross-Sectional Study

BACKGROUND

Thiazide diuretics are a mainstay in the management of hypertension and often associated with dyselectrolytemias. We investigated the prevalence of and risk factors for hyponatremia and hypokalemia in thiazide users, substance-specific differences, and the association of thiazides with syncope and falls.

METHODS

In this cross-sectional analysis all patients admitted to an interdisciplinary emergency department in Switzerland between January 1, 2017, and December 31, 2018, with measurements of serum sodium and potassium were included. Data regarding serum electrolytes and creatinine were analyzed to classify for dysnatremias, dyskalemias, and acute kidney injury. Chart reviews were performed to screen for syncope or falls.

RESULTS

A total of 1604 patients (7.9%) took thiazides. Acute kidney injury was significantly more common in thiazide users (22.1 vs 7%, P < .0001). Hyponatremia (22.1 vs 9.8%, P < .0001) and hypokalemia (19 vs 11%, P < .0001) were more frequent with thiazides. Thiazide use together with higher age and female sex were independent predictors of hyponatremia and hypokalemia. A dose-dependent effect was found for electrolyte disorders, and there was a variance in risk between the investigated substances with chlorthalidone bearing the highest and hydrochlorothiazide the lowest risk. Patients taking thiazide diuretics had significantly more episodes of syncope and falls.

CONCLUSIONS

Thiazide use is a clear risk factor for hyponatremia and hypokalemia. The effect appears to be dose-dependent and highly variable depending on the substance. Syncope and falls seem to be causally related to thiazide use. Especially in patients who are elderly, female, and prone to falls, the use of thiazide diuretics should be thoroughly questioned.

Association between lipid-lowering agents and severe hyponatremia: a population-based case-control study

PURPOSE

Drug-induced hyponatremia is common, with medications from many drug-classes implicated. Lipid-lowering agents are among the most prescribed drugs. Limited evidence suggests an inverse association between statins and hyponatremia, while data on other lipid-lowering agents is absent. The objective of this investigation was to study the association between lipid-lowering drugs and hospitalization due to hyponatremia.

METHODS

This was a register-based case-control study of the general Swedish population. Those hospitalized with a main diagnosis of hyponatremia (n = 11,213) were compared with matched controls (n = 44,801). Multivariable logistic regression adjusting for co-medication, diseases, previous hospitalizations, and socioeconomic factors was used to explore the association between severe hyponatremia and the use of lipid-lowering drugs.

RESULTS

Unadjusted ORs (95% CI) for hospitalization due to hyponatremia were 1.28 (1.22-1.35) for statins, 1.09 (0.79-1.47) for ezetimibe, 1.38 (0.88-2.12) for fibrates, and 2.12 (1.31-3.35) for resins. After adjustment for confounding factors the adjusted odds ratios (95% CI) compared with controls were 0.69 (0.64-0.74) for statins, 0.60 (0.41-0.86) for ezetimibe, 0.87 (0.51-1.42) for fibrates, and 1.21 (0.69-2.06) for resins.

CONCLUSIONS

Use of statins and ezetimibe was inversely correlated with severe hyponatremia. Consequently, these drugs are unlikely culprits in patients with hyponatremia, and they appear safe to initiate in hyponatremic patients. A potential protective effect warrants further studies on how statins and other lipid-lowering drugs are linked to dysnatremias.

Furosemide and spironolactone doses and hyponatremia in patients with heart failure

Background

Hyponatremia, a marker of disease severity and prognosis, has been associated with various clinical factors and drug use, especially diuretics.

Methods

This observational prospective cohort study enrolled patients hospitalized at the University Hospital Center Split because of heart failure (HF). We investigated the association of clinical variables and cardiovascular drugs, including furosemide, hydrochlorothiazide, spironolactone, and their doses, with the presence of hyponatremia at admission.

Results

Of the 565 included patients, 32.4% were hyponatremic, 62.6% were males, and the mean age was 73.1 ± 10.6 years. In the univariate analysis, hyponatremic patients were more often current smokers (p = 0.01), alcohol consumers (p = 0.01), receiving spironolactone (p = 0.004) or combination of furosemide and spironolactone (p = 0.003). Patients who received 50 and 100 mg of spironolactone, compared to those receiving 25 mg (p < 0.0001), as well as patients who received 250 to 500 mg of furosemide compared to ≤240 mg (p = 0.001), were significantly more often hyponatremic. In the multivariate analysis, when diuretic doses were accounted for, furosemide doses of 250 to 500 mg (p = 0.009), spironolactone doses of 50 to 100 mg (p = 0.0003), increasing age (p = 0.03), diabetes mellitus (p = 0.02) and alcohol consumption (p = 0.04) were independently associated with hyponatremia.

Conclusion

High doses of furosemide and spironolactone, or concomitant use of these diuretics, seem to be an important cause of hyponatremia in HF patients, particularly in combination with advanced age, diabetes and alcohol consumption. Diuretic dose reduction may help avoid hyponatremia and improve clinical status and prognosis in such patients.