Comparative Antihypertensive Effects of Hydrochlorothiazide and Chlorthalidone on Ambulatory and Office Blood Pressure

Abstract

Abstract-Low-dose thiazide-type diuretics are recommended as initial therapy for most hypertensive patients. Chlorthalidone has significantly reduced stroke and cardiovascular end points in several landmark trials; however, hydrochlorothiazide remains favored in practice. Most clinicians assume that the drugs are interchangeable, but their antihypertensive effects at lower doses have not been directly compared. We conducted a randomized, single-blinded, 8-week active treatment, crossover study comparing chlorthalidone 12.5 mg/day (force-titrated to 25 mg/day) and hydrochlorothiazide 25 mg/day (force-titrated to 50 mg/day) in untreated hypertensive patients. The main outcome, 24-hour ambulatory blood pressure (BP) monitoring, was assessed at baseline and week 8, along with standard office BP readings every 2 weeks. Thirty patients completed the first active treatment period, whereas 24 patients completed both. An order-drug-time interaction was observed with chlorthalidone; therefore, data from only the first active treatment period was considered.

Physician Underutilization of Effective Medications for Resistant Hypertension at Office Visits in the United States: NAMCS 2006–2010

“…The AHA recommendations for aldosterone antagonist use were only recently published, but the evidence for chlorthalidone has been known for quite some time. 10,33 Why increasing the use of these medications has proven difficult is not well understood, although behavioral norms and entrenched practice patterns biased against their use may contribute to the challenges in increasing their use.…”

“…[5][6][7][8][9][10] The National Ambulatory Medical Care Survey (NAMCS), an annual nationally representative sample of office visits in the US, collects blood pressure measurements, diagnoses and medications. We sought to assess the prevalence of resistant hypertension among office visits to physicians who typically manage hypertension, describe trends in physicians' use of recommended medications 2 years after publication of the AHA guidelines, and determine whether use of recommended medications varied by regional-level, physician-level, or patient-level characteristics.…”

Chlorthalidone Compared With Hydrochlorothiazide in Reducing Cardiovascular Events

“…CTDN decreases vascular permeability and reduces epinephrine-mediated platelet aggregation by inhibiting carbonic anhydrase. 44,45 Another possibility pertains to HCTZ's short duration of action, 3,9,[46][47][48][49] which is 16 to 24 hours after long-term dosing, Յ48 hours for amlodipine, 50 and 48 to 72 hours for CTDN. 9 Nighttime BP more closely predicts cardiovascular risk than 24-hour ambulatory BP, which is more predictive of risk than office BP.…”

Preventing Thiazide‐Induced Hyperglycemia: Opportunities for Clinical Pharmacists

“…I suggest using chlorthalidone because it achieves better 24-hour blood pressure control THIAZIDE-INDUCED HYPERGLYCEMIA Carter with no increase in hypokalemia compared with hydrochlorothiazide. 23 Patients should be monitored closely with a goal of achieving serum potassium levels of 4.0-4.5 mEq/L. 6,24 In our meta-analysis, we found a mean reduction in serum potassium level of 0.23 mEq/L and a mean increase in glucose concentration of 3.26 mg/dl in studies that included potassium supplements or potassiumsparing diuretics.…”