How efficacious are thiazide diuretics in reducing blood pressure?
In the recent systematic review4 the magnitude of reduction in blood pressure was also compiled in the various trials. The weighted net reduction in systolic and diastolic pressure for trials of high-dose thiazide regimens (15/7 mm Hg) as compared with untreated controls was very similar to same values for trials of low-dose thiazide regimens (16/6 mm Hg). This result suggests that, in terms of reducing blood pressure, there is no advantage to using a higher dose, especially when it is considered that high-dose thiazide regimens appear to be associated with less effectiveness in reducing coronary artery events. The magnitude of blood pressure reduction with thiazide regimens compared favourably with either ß-blocker regimens (reduction in blood pressure of 10/6 mm Hg) or CCB regimens (10/5 mm Hg).4 However, the effect of thiazides relative to other classes of drugs is best assessed in direct comparisons in randomized trials. I was able to identify 8 randomized trials comparing thiazide
