our doctor if you have:Belly pain, nausea, or vomiting.Diarrhea.Dizziness, lightheadedness, or fainting.Hallucinations.Headache.Signs of an infection, such as a sore throat, fever, sneezing, or coughing.Trouble sleeping.Unusual body movements, such as twitching.Common side effects of this medicine include:Constipation.Dry mouth.Increased sweating.See Drug