Nephrologist replaced Diovan with Benicar 40 mg 2 weeks ago. Take in a.m. Also, take amlodipine 2.5 at night. BP high after kidney failure; transplant 4 years ago (donor was living relative, excellent match, no steriods at all; creatinine now fluctuates 1.2 - 1.4, GFR ~40). Only problem with Diovan was bad nausea every a.m., no matter how much I ate. With Benicar, I am now nauseated all day, extreme dizziness and loss of balance, very sleepy all day, constant headache - has continued 2 weeks. Neph. said cut in half, so only took 20 mg this morning. Still very nauseated, dizzy, sleepy. Other possible med issue - surgery for ruptured brain aneurysm 10 years ago, so dizziness can be a real problem. Age 60, female - gee, I used to be healthy! Kidney failure due to bladder problems, no history of hi BP until then. Will these awful side effects continue or should I switch back to Diovan? Dr. wants me to keep trying Benicar, but I'm concerned about nausea, dizziness and total lack of energy all day - can't get anything done and won't drive with this dizziness.