The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. This is not a complete list of possible side effects. Many people using this medicine do not have serious side effects. We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Do not increase your dose or use this drug more often or for longer than prescribed. Drowsiness, dizziness, dry mouth, blurred vision, constipation, or trouble urinating may occur. Many people using this medicine do not have serious side effects.