Suzanne66... you are wrong. Hydrochlorothiazide is differemt drug that they sometimes add to medications for diuretic purposes and it can be added to both Benicar and to losartan. It is not a difference between the two drugs. The difference between the two is the base drug. Benicar is Olmesartan, and the base for Losartan is Cozaar, They are two different drugs that do the same thing, Losartan is just less expensive.