The prevalence of hypertension across the globe has almost doubled over the past 25 years. While antihypertensive drugs have been routinely used as the first-line treatment of hypertension, their adverse effects, especially when an additional drug class is added, remain controversial. This study aims to evaluate the incremental effects of adding extra hypertensive drugs in patients with hypertension.

This instrumental variable analysis from the Systolic Blood Pressure Intervention Trial (SPRINT) included a total of 9,092 participants with hypertension and increased cardiovascular risk but no history of stroke or diabetes. The effects of the addition of a second or third class of antihypertensive drugs were evaluated. The primary outcome of the study was systolic blood pressure, major cardiovascular events, and other serious adverse events.

The findings suggested that adding a new class of hypertensive drugs was associated with slightly lower systolic blood pressure (−1.3 mm Hg). No change in the absolute risk of cardiovascular events was discovered. The addition of a new class of antihypertensive drugs was not associated with any adverse events.

The research concluded that the addition of a new class of antihypertensive drugs modestly reduced the systolic blood pressure, and was not associated with an increased risk of cardiovascular or adverse events.