Medication switch Benicar to Diovan

Dear Ask The Doctor: Is Diovan HTC 160mg-12.5 the same dose as Benicar HTC 20-12.5 my health insurance would not cover the Benicar and switched me to the Diovan and just sent it to me without answering the question as to if they were the same dose but just different strength meds. Please help before I take it.

Dear Matt: Diovan HTC contains valsartan (angiotensin II receptor blocker) and hydrochlorothiazide (diuretic). Benicar HTC contains olmesartan (angiotensin II receptor blocker)  and hydrochlorothiazide. So essentially these are similar drugs used in the  treatment of high blood pressure, the only difference is that valsartan is replaced with olmesartan in Benicar HTC. Valsartan and olmesartan belong to the same drug group and have similar mechanism of action, however some studies have shown olmesartan to be slightly more effective than valsartan in reducing diastolic blood pressure at its starting dose.