A meta-analysis of use of hydrochlorthiazide (HCTZ) in management of hypertension has been published in the January issue of J Am Coll Cardiol (1) .
The trials with the following criteria were included in the meta-analysis: 1) randomized trials involving patients with hypertension that assessed the antihypertensive efficacy by 24-h Ambulatory Blood Pressure (ABP) monitoring comparing HCTZ with other antihypertensive drug classes; 2) use of HCTZ as a monotherapy in the trial; and 3) trial duration of at least 4 weeks.
The main outcome of the present analysis was BP (systolic/diastolic) reduction from baseline to follow-up.
Results: The antihypertensive efficacy of HCTZ in the dose of 12.5 to 25 mg was assessed from 14 randomized controlled trials.
· The mean baseline BP in these studies was 148 ± 7.5/92 ± 5.6 mm Hg.
· After treatment with HCTZ for a mean duration of 17 weeks, systolic ABP decreased by 6.5 mm Hg and diastolic ABP by 4.5 mm Hg.
· Other antihypertensive agents such as ACE inhibitors, ARBs, beta-blockers, and calcium antagonists were significantly more efficacious than HCTZ in the dose of 12.5 to 25 mg.
· In head-to-head comparisons with other antihypertensive drug classes, HCTZ in the usual dose of 12.5 to 25 mg lowered systolic ABP less well than ACE inhibitors by 4.5 mm Hg (p = 0.001), ARBs by 5.1 mm Hg, beta-blockers by 6.2 mm Hg (p < 0.00001), and calcium antagonists by 4.5 mm Hg (p = 0.02).
· HCTZ lowered diastolic ABP less well than ACE inhibitors by 4.0 mm Hg (p < 0.0001), ARBs by 2.9 mm Hg (p = 0.002), beta-blockers by 6.7 mm Hg (p < 0.00001), and calcium antagonists by 4.2 mm Hg (p = 0.0001)
· The antihypertensive effect of HCTZ was similar to other antihypertensives in controlling the office BP, whereas it was inferior to other antihypertensives in controlling ABP.
· The authors have mentioned that assessing the antihypertensive efficacy of HCTZ by office BP measurements only is deceptive and is prone to provide to physicians and patients a false sense of security.
· At a daily dose of 50 mg and above, HCTZ's antihypertensive efficacy seems to be similar to most other drug classes. However, all biochemical adverse effects such as hypokalemia, hyponatremia, hyperuricemia, insulin resistance, and visceral fat accumulation are dose dependent and become clinically more significant with daily doses exceeding 25 mg (2).
· In its commonly used dose of 12.5 to 25 mg once a day, there has been no evidence that HCTZ reduces myocardial infarction, stroke, or death.
· Numerous, mostly factorial design studies have shown that when combined with these drug classes, HCTZ, even at low doses, elicits a distinct incremental fall in BP. That indicates that HCTZ is more useful as an "enhancer" or "sensitizer" for the antihypertensive effect of renin-angiotensin system blockers than as a monotherapeutic agent. The ACCOMLISH trial shows HCTZ to be inferior to amlodipine.(3)
· The authors concluded that HCTZ in its commonly used dose of 12.5 to 25 mg daily lowers BP significantly less well than do all other drug classes as measured in head-to-head studies by ABP monitoring.
The meta-analysis has also been discussed on: http://www.theheart.org/article/1176571.do#bib_2
References:
2. Messerli FH, Bangalore S, Julius S. Risk/benefit assessment of beta-blockers and diuretics precludes their use for first-line therapy in hypertension Circulation 2008;117:2706-2715discussion 2715
3. Jamerson K, Weber MA, Bakris GL, et al. Benazepril plus amlodipine or hydrochlorothiazide for hypertension in high-risk patients N Engl J Med 2008;359:2417-2428.
No comments:
Post a Comment