Electrolyte Disturbances after Long term Diuretic Therapy for Hypertensive Patients

Abstract

The aim of the study was to know the extent of electrolyte disturbances in patients with hypertension on long-term diuretic therapy. We analyzed data from 648 patients on antihypertensive medication more than 12 months. Among them 321 patients used diuretics as combination antihypertensive therapies (diuretic treatment group), on the other hand 327 patients took antihypertensive drugs without diuretics (control group). The mean age of the diuretic treatment group was 64.3 10.3 years old (male 43.6%), and it was 63.3 9.9 years old for the control group (male 43.4%). In diuretic group 172 patients (53.6%) used thiazide diuretics (mean dosage 14.6 6.0 mg/d for hydrochlorothiazide). The other patients used furosemide (102 patients, mean dosage 40.4 8.0 mg/d) and torasemide (47 patients, mean dosage 5.7 2.1 mg/d). The mean duration of antihypertensive drug therapies for diuretic and control group were 59.3 42.8 months and 55.7 42.2 months respectively. Concentrations of the sodium and the chloride were decreased in diuretic group after treatment (from 141.3 3.1 mEq/L to 140.9 2.6 mEq/L (p<0.025) and from 106.1 8.2 mEq/L to 104.7 5.8 mEq/L (p<0.015) respectively). On the contrary for the control group these were unchanged by the treatment. Interestingly the blood concentrations of potassium were increased both the diuretic group and the control group (from 4.2 0.4 mEq/L to 4.3 0.4 mEq/L (p<0.025) and from 4.2 0.4 mEq/L to 4.3 0.4 mEq/L (p<0.001) respectively). Among the diuretic group 159 patients (49.5%) used angiotensin converting enzyme inhibitors(ACEI) or angiotensin receptor blockers(ARB) as combination therapy. In these patients the concentrations of potassium is significantly increased despite of combined use of diuretics (from 4.2 0.5 mEq/L to 4.3 0.4 mEq/L (p<0.001)). And for patients who did took nor ACEIs neither ARBs, these were unchanged. In conclusion for hypertensive patients sodium and chloride concentrations are decreased by long term diuretic therapy. Hypokalemia caused by the diuretic therapy is not apparent. The potassium concentration may be more influenced by ACEI or ARB use than the diuretic therapy.