Evening dosing of antihypertensive drugs more effective in lowering blood pressure

Clinical question: 
What are the time-related effects of evening versus morning administration of once-daily antihypertensive drug monotherapy on all-cause mortality, cardiovascular morbidity and blood pressure (BP) reduction in patients with primary hypertension?
Bottom line: 
Based on data for six classes of antihypertensive drugs (ACE inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, alpha- and beta-blockers), evening drug administration caused an additional lowering of 24-hour systolic BP by 1.71mm Hg and 24-hour diastolic BP by 1.38mm Hg. The clinical significance of this is not known. No RCT reported on all-cause mortality, cardiovascular mortality or morbidity and serious adverse events. There were no significant differences between the two regimens on overall adverse effects and withdrawals due to adverse effects.
Caveat: 
Meta-analysis showed significant heterogeneity across trials. Most trials had a risk of bias in at least two of several key criteria.
Context: 
Variations in blood pressure levels display circadian rhythms. The morning surge in blood pressure is known to increase the risk of myocardial events in the first several hours post-awakening. Guidelines have recommended using once-daily, long-acting antihypertensive drugs to provide more consistent 24-hour BP control, reduce BP variability, and improve adherence to therapy.1
Review CD#: 
CD004184
PEARLS No: 
348
Date: 
February, 2012
Authored by: 
Brian R McAvoy