HealthDay News — For patients with stage 1 hypertension, low-dose chlorthalidone is associated with reduction in ambulatory blood pressure (ABP), while low-dose hydrochlorothiazide (HCTZ) may result in masked hypertension, according to a study published in the February 2 issue of the Journal of the American College of Cardiology.
Anil K. Pareek, MD, from Ipca Laboratories Limited in Mumbai, India, and colleagues compared 6.25mg daily chlorthalidone with 12.5mg daily HCTZ via ABP monitoring in a 12-week trial. Fifty-four patients with stage 1 hypertension were randomized to chlorthalidone, HCTZ 12.5mg, or HCTZ-controlled release (CR) 12.5mg (16, 18, and 20 patients, respectively). ABP monitoring was conducted at baseline and after four and 12 weeks of treatment.
The researchers found that office BP was lower at weeks four and 12 from baseline with all 3 treatments (P < 0.01). With chlorthalidone, but not HCTZ, there were significant reductions in systolic and diastolic 24-hour ambulatory and nighttime BP at weeks 4 and 12 (P < 0.01). Nighttime systolic ABP was significantly lower with chlorthalidone versus HCTZ at weeks four (P = 0.015) and 12 (P = 0.020). Sustained hypertension was converted into masked hypertension with HCTZ therapy. The HCTZ-CR group showed a significant reduction in 24-hour ABP compared with HCTZ (P < 0.01).
“Treatment with low-dose chlorthalidone, 6.25mg daily, significantly reduced mean 24-hour ABP as well as daytime and nighttime BP. Due to its short duration of action, no significant 24-hour ABP reduction was seen with HCTZ, 12.5mg daily, which merely converted sustained hypertension into masked hypertension,” the authors write. “Low-dose chlorthalidone, 6.25 mg, could be used as monotherapy for treatment of essential hypertension, whereas low-dose HCTZ monotherapy is not an appropriate antihypertensive drug.”
Several authors are employees of Ipca Laboratories, which supported the study. One author disclosed financial ties to pharmaceutical companies, including Ipca Laboratories.