http://www.medicalnewstoday.com/articles/224743.php
It's a study on mice, mind you, but interesting anyway. The long and short of it is that ACE inhibitors taken in the morning are no more effective than a placebo but taken at bedtime they are much more effective. This has to do with the fact that there is a natural daily cycle in which the levels of a particular hormone increase and night and the ACE inhibitor combats it best if taken when those levels are up, or going up.
It's a study on mice, mind you, but interesting anyway. The long and short of it is that ACE inhibitors taken in the morning are no more effective than a placebo but taken at bedtime they are much more effective. This has to do with the fact that there is a natural daily cycle in which the levels of a particular hormone increase and night and the ACE inhibitor combats it best if taken when those levels are up, or going up.