Determining the Relative Antihypertensive Potency and Relative Cardiovascular Risk Reduction Associated With Different Thiazide and Thiazide-Type Diuretics

摘要

Thiazide-type diuretics were first approved in the United States for hypertension in 1957. Chlorthiazide was the first thiazide diuretic used in clinical practice, but today, more than a half-century later, the two most commonly used thiazide-type diuretics in the treatment of hypertension are hydrochlorthiazide (HCTZ) and chlorthalidone. HCTZ is readily available and included in most fixed-dose antihypertensive combinations. At 12.5 mg/d to 25 mg/d, HCTZ is the most widely used thiazide-like diuretic in current practice, despite the fact that chlorthalidone is generally considered to have greater potency and longer duration of action and has been the diuretic most commonly used in major landmark clinical outcome hypertension trials. SUMMARY OF PAPERS AND COMMENT In order to determine the relative potency and potential for adverse events, Peterzan and colleagues performed a systemic meta-analysis to examine the placebo-adjusted dose-response effect of various doses of HCTZ, chlorthalidone, and bendroflumethiazide monotherapy on blood pressure (BP) and electrolytes. According to this analysis, the estimated dose of each drug predicted to reduce systolic BP by 10 mm Hg was 1.4, 8.6, and 26.4 mg, respectively, for bendroflumethiazide, chlorthalidone, and HCTZ. This 3:1 ratio in BP-lowering potency between chlorthalidone and HCTZ is consistent with previous reports. Similarly, the estimated doses of bendroflumethiazide, chlorthalidone, and HCTZ predicted to reduce serum potassium by 0.4 mmol/L were 4.2, 11.9, and 40.5 mg, respectively, a similar ratio to that seen with BP efficacy.