Direct comparison of doses did not show evidence of dose dependence for blood pressure-lowering for any of the other thiazides for which RCT data were available : bendrofluazide , chlorthalidone , cyclopenthiazide , metolazone or indapamide .
This is based on an informal indirect comparison of results observed in other Cochrane review s on ACE inhibitors , ARBs and renin inhibitors compared with placebo , which used similar inclusion /exclusion criteria to the present review .Thiazides reduced potassium , increased uric acid and increased total cholesterol and triglycerides .
These effects were dose-related and were least for hydrochlorothiazide .
Chlorthalidone increased serum glucose but the evidence was unclear for other thiazides .
This systematic review shows that hydrochlorothiazide has a dose-related blood pressure-lowering effect .
Thiazides reduced potassium , increased uric acid and increased total cholesterol and triglycerides
BACKGROUND Hypertension is a modifiable cardiovascular risk factor .
Although it is established that low-dose thiazides reduce mortality as well as cardiovascular morbidity , the dose-related effect of thiazides in decreasing blood pressure has not been subject to a rigorous systematic review .
It is not known whether individual drugs within the thiazide diuretic class differ in their blood pressure-lowering effects and adverse effects .
OBJECTIVES To determine the dose-related decrease in systolic and /or diastolic blood pressure due to thiazide diuretics compared with placebo control in the treatment of patients with primary hypertension .
Secondary outcomes included the dose-related adverse events leading to patient withdrawal and adverse biochemical effects on serum potassium , uric acid , creatinine , glucose and lipids .
Low-dose diuretic therapy for hypertension.
The efficacy of low dosages of diuretics was evaluated in two studies . In one , 62 ( 48 % ) of 130 patients became normotensive with 2.5 mg/day of metolazone . In the other , 28 ( 49 % ) of 57 patients became normotensive with 25 mg of chlorthalidone , compared with 12 ( 22 % ) of 55 patients given placebo . There was a marked variation in blood pressure response and the occurrence of hypokalemia ( less than 3.5 mEq/L of potassium ) from center to center and within patient groups in both studies . The mean decrease in serum potassium was between 0.5 and 0.6 mEq/L in the metolazone group and 0.44 mEq/L in the chlorthalidone-treated patients . This degree of hypokalemia is only slightly less than that noted when larger dosages of thiazide diuretics are used ( 0.6 to 0.7 mEq/L ) . It is concluded that 2.5 mg/day of metolazone or 25 mg/day of chlorthalidone are effective antihypertensive agents but that blood pressure lowering may be inconsistent at these dosage levels . It is reasonable , therefore , to begin diuretic therapy with low dosages , but larger dosages ( 5 mg of metolazone or 50 mg of chlorthalidone ) should be tried before adding another drug or concluding that diuretic therapy is ineffective if an acceptable blood pressure response is not obtained . The degree of hypokalemia that occurs at lower-dose therapy is variable but may be of less clinical significance than that noted with higher dosages of diuretics in some patients . ( ABSTRACT TRUNCATED AT 250 WORDS
Direct comparison of doses did not show evidence of dose dependence for blood pressure-lowering for any of the other thiazides for which RCT data were available : bendrofluazide , chlorthalidone , cyclopenthiazide , metolazone or indapamide .
This is based on an informal indirect comparison of results observed in other Cochrane review s on ACE inhibitors , ARBs and renin inhibitors compared with placebo , which used similar inclusion /exclusion criteria to the present review .Thiazides reduced potassium , increased uric acid and increased total cholesterol and triglycerides .
These effects were dose-related and were least for hydrochlorothiazide .
Chlorthalidone increased serum glucose but the evidence was unclear for other thiazides .
This systematic review shows that hydrochlorothiazide has a dose-related blood pressure-lowering effect .
Thiazides reduced potassium , increased uric acid and increased total cholesterol and triglycerides
BACKGROUND Hypertension is a modifiable cardiovascular risk factor .
Although it is established that low-dose thiazides reduce mortality as well as cardiovascular morbidity , the dose-related effect of thiazides in decreasing blood pressure has not been subject to a rigorous systematic review .
It is not known whether individual drugs within the thiazide diuretic class differ in their blood pressure-lowering effects and adverse effects .
OBJECTIVES To determine the dose-related decrease in systolic and /or diastolic blood pressure due to thiazide diuretics compared with placebo control in the treatment of patients with primary hypertension .
Secondary outcomes included the dose-related adverse events leading to patient withdrawal and adverse biochemical effects on serum potassium , uric acid , creatinine , glucose and lipids .