How much will hydrochlorothiazide (HCTZ) lower my blood pressure?

Evidence shows that lowering blood pressure (BP) decreases the risk of adverse cardiovascular outcomes such as heart disease, stroke, and death.^1-4 It may also slow the progression of kidney damage in people with chronic kidney disease.⁵ Further, meta-analyses as well as national and international guidelines suggest that lowering BP decreases risk of these outcomes regardless of which agent is used.^1-4,6

Hydrochlorothiazide (HCTZ) is a first-line treatment for all stages of hypertension as a monotherapy or in combination with one or more other antihypertensive agents.^2,3,6

Monotherapy trials show the BP lowering efficacy of HCTZ.^6-15 A 2014 Cochrane Review meta-analysis found 60 randomized controlled trials that studied the dose-related trough BP lowering efficacy of six different thiazide diuretics in 11,262 participants.⁶ The baseline BP was 155/100 mm Hg across the trials. 33 trials looked at HCTZ specifically. The analysis found mean BP lowering effect over the dose range 6.25 mg, 12.5 mg, 25 mg, and 50 mg/day is -4/-2 mmHg, -6/-3 mmHg, -8/-3 mmHg and -11/-5 mmHg, respectively.

^References

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5. KDIGO 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Int Suppl (2011) 2013; 3 (1): i-150.
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