My husband aged 69 had a heart attack 6 years ago, followed by 5 way bypass. He developed vascular disease 2 weeks after surgery. With the harsh pain killers his kidneys were working only 40% With life style changes, exercise and diet he has been healthy after that and his kidneys are working much better than before. The only medication he has been taking for the last 6 years is Plavix and Xyloric. He was on Diovan after the heart attack and after the bypass but we had to discontinue it as his blood pressure was going as low as 85/53. So for the last 6 years his blood pressure has been normal without Diovan. Recently however, his blood pressure has risen to 189-94 etc during the day. In the mornings it is 124-70 etc. His cardiologist put him on Diovan-80 10 days ago. His pressure is 156-94 but at night it goes as low as 88-53. His doctor asked him to take Diovan after breakfast because it goes so low. What can we do to stabilise it? How long does Diovan take to kick in? He is still working as we have our own business.He has borderline diabetes which he keeps in check with alternative therapy.