Hypertension, the changing pattern of drug usage.

Gradually the pattern of use of antihypertensive drug agents has changed, from prime use of diuretics and beta-blockers, to preference for the inhibitors of the renin-angiotensin system and the calcium channel blockers. In assessing the value of potentially conflicting evidence, attention should be paid to the hierarchy of evidence, which works its way up through 10 steps from isolated case reports to integrated knowledge.