Ramipril decreases chlorthalidone-induced loss of magnesium and potassium in hypertensive patients.
A double-blind clinical trial was conducted to compare the efficacy of and electrolyte changes caused by ramipril-chlorthalidone combination treatment (5 mg + 25 mg) and chlorthalidone monotherapy (25 mg daily) in patients with hypertension. After a 4-week placebo period, 32 patients (mean age, 51 +/- 9 years) with essential hypertension (average blood pressure of 181.4/104.5 +/- 13.0/6.9 mmHg) were randomly assigned to receive combination therapy (group A, n = 17) or monotherapy (group B, n = 15). After 12 weeks of active treatment, systolic and diastolic blood pressure decreased by 16.1% and 13%, respectively, for patients taking combined therapy, and by 12.7% and 9.8%, respectively, for patients taking monotherapy. The difference was significant for between-group comparisons. There were no changes in serum sodium concentration, but a significant similar increase in 24-hour urinary sodium excretion was seen in both groups. Serum calcium levels increased slightly and 24-hour urinary calcium excretion decreased significantly in both groups, probably due to chlorthalidone administration. Serum potassium levels increased slightly in group A (from 4.16 +/- 0.39 mmol/L to 4.30 +/- 0.42 mmol/L) and decreased slightly in group B (from 4.18 +/- 0.32 mmol/L to 3.99 +/- 0.49 mmol/L). Urinary potassium excretion did not change significantly in group A, but increased by approximately 15% in group B. There was a decrease in 24-hour urinary magnesium excretion (from 4.01 +/- 1.24 mmol/24 hours to 3.50 +/- 0.93 mmol/24 hours) in group A and an increase (from 3.49 +/- 0.98 mmol/24 hours to 4.35 +/- 1.12 mmol/24 hours) in group B. At the end of the trial these changes were significant in between-group comparisons. Consistent with the previously shown amelioration by ramipril of thiazide-induced metabolic side-effects, ramipril appears to improve magnesium balance during cotreatment with chlorthalidone.
Simunic
M
M
Department of Medicine, Clinical Hospital Split, Croatia.
Rumboldt
Z
Z
Ljutic
D
D
Sardelic
S
S
D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D002752:Chlorthalidone / Q000008:administration & dosage / Q000009:adverse effects*; D004232:Diuretics / Q000008:administration & dosage / Q000009:adverse effects*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000378:metabolism*; D011446:Prospective Studies; D017257:Ramipril / Q000008:administration & dosage / Q000494:pharmacology*
D000806:Angiotensin-Converting Enzyme Inhibitors; D004232:Diuretics; D008274:Magnesium; D017257:Ramipril; D002752:Chlorthalidone; D011188:Potassium