Taking olmesartan medoxomil and amlodipine for high blood pressure. Have noticed that when I exercise, after about 20 min, my blood pressure drops steadily, like to 77/42, and I have to quit. Worse in the outdoor heat. Seems like my vasodilation mechanism has gotten out of whack because of the olmesartan. What do you think, and what can I do? (The olmeartan-amlodipine combo works fine for keeping down by bp.) Thanks.