I was taking diovan for over one year, and blood pressure was still very high. Now I take diovan with hydrochlorot. Why do you need to take both together is my question. In the beginning dr. had me on hrdrochlorot alone. I went back a few weeks later, and she said she was changing my meds. Hence, I was on diovan. She never told me to keep on the hydro's along with the diovan. Now a year later, she tell's me that I was supposed to be on both the whole year. No wonder my blood pressure is still very high. Can any damage be done to my body as a result of taking one medication without the other for a year?