I have been on 50mg Cozaar for HTN for about 5 years. My BP has been very well controlled. 2 months ago, my BP started spiking up to 150's 160's as high as 190 Systolic and over 110's Dystolic. There have been stressful events during this time as well. My Cozaar has been increased to a additional 25mg in the evening now. We've tried HCTZ, but due to high blood sugars had to DC that, and we tried Toprol XL 12.5mg and I had tightness in my chest. How long does it take for levels of Cozaar to reach a peak in your blood stream to try to see if this is going to be enough to get my BP under some control. It is better now in the 140's systolic and mostly under 100 dystolic for the last few days.