A chronotherapeutic approach to effective blood pressure management

Abstract

The major randomized trials in hypertension have unequivocally demonstrated the benefits of treatment. None of these trials have sought to address the issue of the potential superiority of 24-hour blood pressure control. However, there is a volume of epidemiologic evidence to suggest that prevention of target organ damage requires the sustained reduction of blood pressure throughout the full 24-hour period between doses. Historically, some antihypertensive drugs have been approved for use at high doses to achieve apparent blood pressure control at the end of the once-daily dosing interval. This approach is flawed; attention is focused on this single time point at the end of the dosing interval, without due regard to the antihypertensive response during the rest of the dosing interval. Subsequently, guidelines formulated by the US Food and Drug Administration suggest that all antihypertensive drugs should consistently achieve a trough:peak ratio decline in blood pressure of at least 50%. Evidence suggests that antihypertensive drugs, such as calcium antagonists and angiotensin II receptor blockers, differ in their ability to provide 24-hour blood pressure control. For example, unlike some other angiotensin II receptor blockers, telmisartan provides consistent reduction of blood pressure during the 24-hour period.

Figure 1

Mean ambulatory diastolic blood pressure profiles measured over a 24‐hour period ²

Figure 2

Comparison of the reduction in ambulatory systolic blood pressure (SBP) induced by telmisartan 40 mg and losartan 50 mg, measured over a 24‐hour period ²²

Figure 3

Comparison of the reduction in ambulatory blood pressure induced by telmisartan 40 mg and losartan 50 mg, measured over the last 6 hours of the dosing period. A: Change in systolic blood pressure (SBP). B: Change in diastolic blood pressure (DBP). *Significant difference compared with placebo; ⁺significant difference compared with losartan ²²

Figure 4

Comparison of the reduction in diastolic blood pressure induced by telmisartan (solid bars) and amlodipine (open bars), measured over 24 hours during the day, during the night, over the last 4 hours of the dosing period, and in the morning. *Significant difference between treatments ²⁵