SIDE EFFECTS: Drowsiness, dizziness, tiredness, headache, constipation, weight gain, fever, cough, drooling, trouble sleeping, or nausea may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor immediately if any of these unlikely but serious side effects occur: slow/shallow breathing, mental/mood/behavior changes (e.g., agitation, nervousness, confusion, memory loss), muscle weakness, loss of coordination, shaking (tremor) of the fingers,vision changes (e.g., blurred vision, double vision), slurred speech, decrease in sexual interest, painful urination.A small number of people who take anticonvulsants for any condition may experience depression, suicidal thoughts/attempts, or other mental/mood problems. Tell your doctor immediately if you or your family/caregiver notice any unusual/sudden changes in your mood, thoughts, or behavior including signs of depression, suicidal thoughts/attempts, thoughts about harming yourself.A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist