Topamax

Generic name: Topiramate

What is Topamax?

Topamax is an antiepileptic drug, prescribed to control both mild attacks known as partial seizures and severe tonic-clonic convulsions known as grand mal seizures. It is typically added to the treatment regimen when other drugs fail to fully control a patient's seizures.

Topamax is also prescribed for the prevention of migraine headaches. However, due to a lack of studies, it is not known whether the drug can treat a migraine once it has already started.

What is the most important information I should know about Topamax?

Topamax has been known to cause a potentially serious condition called metabolic acidosis (an increase of acid in the blood). In children, chronic metabolic acidosis may affect growth or cause rickets (a softening or weakness of the bones that can lead to bone deformities). Contact your doctor immediately if you experience symptoms of metabolic acidosis such as rapid breathing, an irregular heartbeat, confusion, lethargy, fatigue, or loss of appetite. Your doctor will decide if you should stop taking Topamax. Do not abruptly stop taking Topamax on your own; your doctor will gradually taper the dosage to avoid an increase in seizures.

Topamax has been known to trigger severe nearsightedness along with increased pressure inside the eye. The problem usually occurs within 1 month of starting treatment. If you develop blurred vision or eye pain, call your doctor immediately. You may have to stop taking the drug in order to prevent permanent vision loss.

Who should not take Topamax?

Do not take Topamax if you are allergic to the medication or any or its ingredients.

What should I tell my doctor before I take the first dose of Topamax?

Mention all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with Topamax. Also, talk to your doctor about your complete medical history, especially if you have: asthma, bronchitis, emphysema, glaucoma, growth problems, kidney disease or a history of kidney stones, liver disease, metabolic acidosis (blood and body fluid abnormality), osteoporosis (weak or brittle bones) and/or soft bones (osteomalacia) or decreased bone density (osteopenia), or paresthesia.

Be sure to let your doctor know if you are on a high-fat diet, called a ketogenic diet, or if you have recently had surgery.

What is the usual dosage?

The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

Adults: If you have liver or kidney problems, or are undergoing hemodialysis, the doctor may need to adjust the dosages listed below.

Prevention of Migraine Headaches

Adults: The recommended total daily dose is 100 milligrams (mg) a day, taken in two divided doses. Your doctor will increase the dose slowly over 4 weeks. The usual regimen is as follows:

Week 1: No morning dose; take 25 mg at night.

Week 2: Take 25 mg in the morning and another 25 mg at night.

Week 3: Take 25 mg in the morning and 50 mg at night.

Week 4: Take 50 mg in the morning and 50 mg at night.

Seizures

Adults: Topamax therapy usually begins with a dose of 25 mg twice a day during the first week. The daily dosage is then increased each week until you are taking 200 mg twice a day by the eighth week.

If you are also taking phenytoin or carbamazepine, the dosage of Topamax may need to be adjusted.

Children: The usual daily dose for children 2 to 16 years of age is 5 to 9 mg for every 2.2 pounds of body weight, divided into two doses. Topamax therapy usually begins with a dose of 25 mg (or less) once daily during the first week. The daily dosage is then increased each week until the doctor is satisfied with the response. It may take eight weeks to reach the ideal dose.

How should I take Topamax?

It is important to take Topamax exactly as prescribed. You can take it with or without food, but because of the medication's bitter taste, you should avoid breaking the tablets.

You can swallow Topamax capsules whole, or you can open the capsule and sprinkle its contents on a teaspoonful of soft food. To open the capsule, hold it so you can read the word "top" and carefully twist off the clear portion of the capsule. Do not chew the drug and food mixture; swallow it whole. Do not store the mixture for future use.

Topamax increases your risk of developing kidney stones. To prevent this problem, be sure to take Topamax with plenty of fluids.

What should I avoid while taking Topamax?

If you are taking Topamax or other antiepileptic drugs for epilepsy or seizures, you may need to avoid activities where loss of consciousness (passing out) could result in serious danger to yourself or those around you. Talk to your doctor before engaging in activities such as swimming, driving a car, and climbing in high places.

Do not drive a car or operate heavy machinery until you know how Topamax affects you. Topamax can impair your thinking, motor skills, and/or vision.

Avoid drinking alcoholic beverages with Topamax.

Unless prescribed by your healthcare professional, you should avoid other medicines like central nervous system depressants, which also impair or decrease your thinking, concentration, or muscle coordination.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Drink extra fluids in these situations.

What are possible food and drug interactions associated with Topamax?

If Topamax is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Topamax with the following: acetazolamide, amitriptyline, carbamazepine, dichlorphenamide, digoxin, metformin, phenytoin, oral contraceptives, risperidone, or valproic acid.

Topamax can depress the central nervous system. Be extremely cautious about combining it with alcohol, sedatives, tranquilizers, and other central nervous system depressants.

What are the possible side effects of Topamax?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

Side effects may include: diarrhea, hair loss, loss of appetite, nausea, taste change, tingling in arms and legs, tiredness, upper respiratory tract infection, viral infection, weight loss

Can I receive Topamax if I am pregnant or breastfeeding?

The effects of Topamax during pregnancy and breastfeeding are unknown. Tell your doctor immediately if you are pregnant, plan to become pregnant, or are breastfeeding.

What should I do if I miss a dose of Topamax?

Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Never take two doses at once.

How should I store Topamax?

Store at room temperature in a tightly closed container. Protect the tablets from moisture.