ey damage, nerve damage, blindness, problems with circulation (blood movement in your body), loss of feet, legs or other limbs, high blood pressure, heart attack, or stroke.GLUCOTROL XL works mainly by:helping the body release more of its own insulinhelping the body respond better to its own insulinlowering the amount of sugar (glucose) made by the bodyEven after you start taking GLUCOTROL XL, you