Do not give up taking it except on the advice of your doctor. Many people using this medicine do not have serious side effects. Get medical help right away if you have any very serious side effects, including: severe dizziness, fast/irregular heartbeat, fainting, seizures, eye pain/swelling/redness, widened pupils, vision changes (such as seeing rainbows around lights at night). Older adults may be more sensitive to the side effects of this drug, especially dry mouth, dizziness, drowsiness, confusion, difficulty urinating and QT prolongation (see above). We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Some conditions may become worse when this drug is suddenly stopped.