I'm A 67 Yr Old Af Amer Female In Good

I'm a 67 yr old Af Amer female in good health. This year my doctor prescribed Zestoretic for high blood pressure which I've never had before. I have gained about 15 pounds so shouldn't I first loose wt before taking a medication. Will I have to stay on this forever? Is it OK to use the generic lisinopril HCTZ. He also prescribed Lipitor for cholesterol (I haven't filled it) which has always been good. He's a geriatic MD and I think he prescribes based on age.