I've been on TOPROL-XL( 50 mg) for about 18 months now. Gained 2...

I've been on TOPROL-XL( 50 mg) for about 18 months now. Gained 25 lbs. Lack of interest (consistently) in getting much done. I had an aortic valve replacement 12 years ago and they were recently concerned about an enlargement of the aorta-so they wanted the Toprol to reduce the blood pressure further. Its keeping the pressure steady but not a huge decrease. When I discuss the side effects- they smile beningly. I'm having difficulty with digestive tract issues, also, which seem to be connected with weight gain. Other than fluuid retention- anybody know WHY this cuases weight gain? Anybody had any luck switching to other medications??