Dizziness, drowsiness, trouble sleeping, lack of coordination, lightheadedness, loss of appetite, diarrhea, or double vision may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Remember that this medication has been prescribed because your doctor 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 right away if you have any serious side effects, including: mental/mood problems (such as confusion, difficulty concentrating, memory problems, agitation, irritability), speech problems, decreased sweating, sudden back/side/abdominal pain, painful urination.
A small number of people who take anticonvulsants for any condition (such as seizure, bipolar disorder, pain) may experience depression, suicidal thoughts/attempts, or other mental/mood problems. Tell your doctor right away 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.
This medication may cause a serious metabolic problem (metabolic acidosis). Get medical help right away if you have any of the following symptoms: bone pain/breakage, rapid breathing, fast/irregular heartbeat, sudden/unexplained tiredness, severe drowsiness/difficulty staying awake.
Get medical help right away if you have any very serious side effects, such as: easy bruising/bleeding, eye pain/redness, vision changes (such as decreased vision, blurred vision), signs of kidney problems (such as change in the amount of urine, pink/bloody urine), signs of liver problems (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine).
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: fever, swollen lymph nodes, 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.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.