Source: Hypertension  |  Posted 9 years ago

Bedtime administration of graded-release diltiazem is more effective at reducing mean blood pressure between 6 AM and noon than is morning administration of the same drug.

The hours between 6 AM and noon is the time when circadian blood pressure is highest, explain investigators from School of Public Health at the University of Minnesota in Minneapolis, Minnesota, United States.

In addition, they report that graded-release diltiazem administered at bedtime reduces blood pressure and heart rate over a 24-hour interval in a dose-dependent manner.

Four hundred seventy-eight patients with moderate to severe essential hypertension participated in a seven-week, randomized, double blind study. A chronotherapeutic, graded-release diltiazem HCl extended-release 120-, 240-, 360-, and 540-milligram dose administered at 10 PM was compared with placebo and a 360-milligram dose of graded-release diltiazem administered at 8 AM.

Bedtime doses of 240 mg and higher reduced trough diastolic blood pressure from 6 PM to 10 PM and mean diastolic blood pressure from 6 AM to noon in a dose-dependent manner.

A bedtime dose of 360 mg reduced mean diastolic blood pressure from 6 AM to noon significantly more than did an 8 AM dose of 360 mg.

Systolic blood pressure and heart rate showed similar dose-related reductions.

Adverse events were lower in all the graded-release diltiazem groups than in placebo group. The group receiving 540 mg showed similar adverse events to the 240-mg group.