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). If you think you have used too much of this medicine seek emergency medical attention right away. It is important to continue taking this medication even if you feel well. To relieve dry mouth, suck on (sugarless) hard candy or ice chips, chew (sugarless) gum, drink water, or use a saliva substitute. Use sunscreen and wear protective clothing when outdoors. Use sunscreen and wear protective clothing when outdoors. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting.