Do NOT use Topamax if:

• you are allergic to any ingredient in Topamax
• you are taking a carbonic anhydrase inhibitor (eg, acetazolamide).

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Topamax. Tell your health care provider if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have liver or kidney problems, kidney stones, osteoporosis (weak bones), or metabolic problems, you drink alcohol regularly, or you are on a ketogenic diet
• if you have diarrhea, lung or breathing problems, or low bicarbonate levels in the blood, or you will be having surgery
• if you have a history of status epilepticus (continuous seizure activity or a series of seizures without a full return to consciousness)
• if you have a history of mental or mood problems, or suicidal thoughts or actions.

Some medicines may interact with Topamax. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Anticholinergics (eg, benztropine), carbonic anhydrase inhibitors (eg, acetazolamide), haloperidol, or tricyclic antidepressants (eg, nortriptyline) because the risk of decreased sweating may be increased
• Valproic acid because a serious side effect with symptoms of confusion, lethargy, and vomiting may occur
• Metformin or pioglitazone because blood glucose control may be altered; monitor your blood sugar carefully if you use Topamax with metformin or pioglitazone
• Hydrochlorothiazide because it may increase the risk of Topamax's side effects
• Carbamazepine or hydantoins (eg, phenytoin) because they may decrease Topamax's effectiveness
• Amitriptyline because the risk of its side effects may be increased by Topamax
• Lithium because Topamax may have an effect on lithium blood levels
• Hormonal birth control (eg, birth control pills) or risperidone because their effectiveness may be decreased by Topamax.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Topamax may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Topamax may cause drowsiness, dizziness, confusion, or trouble concentrating. These effects may be worse if you take it with alcohol or certain medicines. Use Topamax with caution. Do not drive or perform other possible unsafe tasks until you know how you react to it.
• Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Topamax; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
• Topamax may reduce sweating, which could raise body temperature, especially in children. This risk is greater in hot weather and/or during vigorous exercise. Drink plenty of fluids. Dress lightly while in hot climates or when exercising. Check carefully for signs of decreased sweating. If this occurs, promptly seek cooler or air-conditioned shelter and/or stop exercising. Seek medical attention right away if you have unexplained fever, or if you have mental or mood changes, headache, or dizziness.
• Tell your doctor or dentist that you take Topamax before you receive any medical or dental care, emergency care, or surgery.
• Hormonal birth control (eg, birth control pills) may not work as well while you are using Topamax. To prevent pregnancy, use an extra form of birth control (eg, condoms).
• Lab tests, including serum bicarbonate levels, may be performed while you use Topamax. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
• Use Topamax with caution in the elderly; they may be more sensitive to its effects.
• Caution is advised when using Topamax in children; they may be more sensitive to its effects, especially decreased sweating and decreased bicarbonate levels.
• Topamax may affect growth rate in children and teenagers in some cases. They may need regular growth checks while they take Topamax.
• Topamax should be used with extreme caution in children for migraines and in children  younger than 2 years old for seizures; safety and effectiveness in these children have not been confirmed.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Topamax while you are pregnant. Topamax is found in breast milk. If you are or will be breast-feeding while you use Topamax, check with your doctor. Discuss any possible risks to your baby.

All medicines may cause side effects, but many people have no, or minor, side effects.

Check with your doctor if any of these most common side effects persist or become bothersome:

Constipation; decreased sweating; diarrhea; dizziness; drowsiness; dry mouth; flu-like symptoms; headache; loss of appetite; nausea; nervousness or anxiety; numbness or tingling of the skin; runny nose; sore throat; stomach pain or upset; taste changes; tiredness; trouble sleeping; weight loss.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blood in the urine; blurred vision; bone pain; chest pain; confusion; decreased coordination; depression; double vision or other vision changes; eye pain; irregular heartbeat; loss of consciousness; memory problems; menstrual changes; mental or mood changes; muscle or joint pain, cramps, or weakness; rapid, shallow breathing; red, swollen, blistered, or peeling skin; ringing in the ears; severe or persistent loss of appetite; severe stomach, side, or back pain; significant weight loss; speech problems; stupor; suicidal thoughts or actions; tremor; trouble thinking, concentrating, or remembering things; trouble walking; unexplained fever; unusual bruising or bleeding; unusual eye movements; unusual tiredness.

 This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.