Prevention of Morning Surge of Hypertension by the Evening Administration of Carvedilol

Object To test the clinical usefulness of chronotherapy with a -blocker, evening carvedilol administration was added to first-line antihypertensive therapy in patients with essential hypertension showing a morning blood pressure surge. Methods Patients with hypertension (12 men and 5 women) were treated with first-line antihypertensive drugs for 4 weeks and then underwent 24-hr ambulatory blood pressure monitoring. Patients (6 men and 3 women) who still had high blood pressure exceeding 140/90mmHg in the morning were given carvedilol (10mg/day) as a single dose in the morning or evening in a randomized, crossover open-label protocol. After 4 weeks, ambulatory systolic blood pressure, diastolic blood pressure, and pulse rate were reassessed by 24-hr monitoring. Results Evening carvedilol administration significantly suppressed the morning surge, while morning administration lacked an significant anti-surge effect. The 24-hr mean systolic pressure was also significantly reduced by evening carvedilol administration. Evening administration significantly decreased the early morning, but not the nocturnal, pulse rate. Conclusions Evening carvedilol administration significantly suppressed the morning increases in systolic pressure and pulse rate. The addition of chronotherapy with carvedilol may be an effective way to suppress morning surges of hypertension.