I'm a 80 yr old woman, who had by pass surgery 7mo ago, I have never taken high pressure medicine all these years, but after surgery, they gave it to me a very low dose 25mg 2x a day. The b/p kept going down to less then 100/60, so the doctor dropped me down to taking 12.5me 2x a day. It seams like after I eat and take my medication the b/p drops down and I get so weak and tired I have to sleep, I don't get dizzy. I tried only taking the b/p medicine in the morning only, and I feel much better, and don't have to take a nap. Can someone explain or show me where to find more information. Thank you for any help.