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|Topamax Topamax

Topamax

Generic name: Topiramate
Brand names: Topamax

Why is Topamax prescribed?

Topamax is an antiepileptic drug, prescribed to control both the mild attacks known as partial seizures and the 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 attacks.

Topamax is also prescribed for the prevention of migraine headaches (also known as prophylactic treatment). However, due to a lack of studies, it"s not known whether the drug can treat acute migraine attacks.

Most important fact about Topamax

Do not abruptly stop taking Topamax. If the drug isn"t withdrawn gradually, the frequency of your seizures could increase.

How should you take Topamax?

It is important to take Topamax exactly as prescribed. It can be taken with or without food. Avoid breaking the tablets; the medication has a bitter taste.

Topamax capsules may be swallowed whole, or the capsule may be opened and its contents sprinkled 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. The drug and food mixture should be swallowed whole and not chewed. 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.

--If you miss a dose...

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.

--Storage instructions...

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

What side effects may occur?

Some side effects, such as fatigue, are more likely to surface with high doses of Topamax. Others occur regardless of dosage. While many tend to disappear after the first 8 weeks of therapy, it"s still important to report them to your doctor. Only your doctor can determine if it is safe for you to continue taking Topamax.

• More common side effects may include:
  Abdominal pain, abnormal coordination, abnormal vision, agitation, anxiety, appetite loss, back pain, breast pain, chest pain, confusion, constipation, depression, difficulty with concentration, difficulty with memory, dizziness, double vision, drowsiness, fatigue, flu-like symptoms, indigestion, language problems, leg pain, loss of coordination, menstrual problems, mood problems, nausea, nervousness, nose inflammation, rash, sinusitis, slowing of movements, sore throat, speech problems, tingling or burning sensations, tremors, weakness, weight loss

In children, the more common side effects are abnormal gait, aggressiveness, behavior problems, confusion, constipation, difficulty concentrating, difficulty with memory, difficulty sleeping, dizziness, drowsiness, fatigue, increased muscle movement, increased saliva, injury, loss of appetite, loss of coordination, nausea, nervousness, nosebleed, pneumonia, rash, speech problems, urinary incontinence, viral infection, and weight loss.

Other, less common side effects in children include allergic reaction, digestive inflammation, increased thirst, skin disorders, slowing of movement, vaginal discharge, vision disorders, and weakened reflexes.

Topamax has also been known to cause a number of very rare side effects in adults and children (typically striking less than one person in a hundred). If you develop any unfamiliar problems while taking Topamax, report them to your doctor.

Why should Topamax not be prescribed?

If Topamax gives you an allergic reaction, you"ll be unable to use the drug.

Special warnings about Topamax

Because Topamax sometimes causes confusion, dizziness, fatigue, and problems with coordination and concentration, you should not drive, operate machinery, or participate in any hazardous activity that requires full mental alertness until you are certain how the drug affects you.

Topamax has been known to cause a potentially serious condition known as 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 discontinue 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. Discontinuation of the drug may be necessary to prevent permanent vision loss.

In children with chronic diarrhea or untreated kidney disorders, use of Topamax may lead to rickets and reduced growth rates.

Tell your doctor if you have kidney problems or if you are on hemodialysis; your dosage of Topamax may need adjustment. Elderly patients in particular may experience reduced kidney function when taking Topamax. Also make sure the doctor is aware of any liver disorder you may have. Topamax must be used cautiously by individuals with impaired liver function.

Anyone using Topamax, particularly children, should be carefully monitored by their doctor for signs of increased body temperature or decreased sweating, especially during hot weather.

In rare instances, suicide attempts have been reported in people taking Topamax.

Possible food and drug interactions when taking 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:

Acetazolamide (Diamox)
Carbamazepine (Tegretol)
Dichlorphenamide (Daranide)
Digoxin (Lanoxin)
Metformin (Glucophage)
Phenytoin (Dilantin)
Oral contraceptives
Valproic acid (Depakene)

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

Special information if you are pregnant or breastfeeding

In animal studies, Topamax has caused harm to the developing fetus, and its safety has not been verified in pregnant humans. It is recommended for use during pregnancy only if the doctor feels that its potential benefit outweighs the potential risk to the infant.

This medication may appear in breast milk, and its possible effect on the nursing infant remains unknown. Check with your doctor if you plan to breastfeed your baby.

Recommended dosage

ADULTS

For Seizures

Topamax therapy usually begins with a dose of 50 milligrams once daily during the first week. The daily dosage is then increased each week until, by the eighth week, the patient is taking 200 milligrams twice a day.

If you are also taking Dilantin or Tegretol, the dosage of Topamax may need adjustment.

For Prevention of Migraine Headaches

The recommended total daily dose is 100 milligrams 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 milligrams at night. Week 2: Take 25 milligrams in the morning and again at night. Week 3: Take 25 milligrams in the morning and 50 milligrams at night. Week 4: Take 50 milligrams in the morning and again at night.

CHILDREN

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

DOSAGE ADJUSTMENT

For people with poor kidney function, the dosage is usually cut in half. On the other hand, those undergoing hemodialysis may need a supplemental dose. Likewise, the doctor may adjust your dosage if you have liver problems.

Overdosage

Any medication taken in excess can have serious consequences. If you suspect an overdose of Topamax, seek medical attention immediately.

• Symptoms of Topamax overdose may include:
  Abdominal pain, agitation, blurred vision, convulsions, depression, dizziness, double vision, drowsiness, impaired coordination, impaired mental activity, low blood pressure, reduced consciousness, severe diarrhea, sluggishness, speech problems

A Topamax overdose may result in metabolic acidosis (see "Special warnings about Topamax").