Topamax

What is it?

An anticonvulsant and sulphamate, available as film-coated tablets in 4 strengths containing topiramate, all marked with strength and name. White, contain 25mg; pale yellow, contain 50mg; yellow, contain 100mg; pink, contain 200mg. Also, TOPRAMAX SPRINKLE, clear capsules enclosing white spherical granules in 3 strengths containing 15mg, 25mg and 50mg of topiramate, all marked with strength and TOY

Medical Uses

As additional treatment for partial seizures which may be accompanied by secondary generalised seizures; in patients whose condition is not controlled by other anticonvulsants, for the treatment of primary, generalised tonic clonic seizures. Also, Lennox Gastaut syndrome.

Dosage

Adults, start with 25mg each day for 1 week then dose is increased by 25 to 50mg in 2 divided doses each day. Then increase again by same increments at 1 to 2 week intervals to a usual maintenance dose in the order of 200 to 400mg each day in 2 divided doses. The maximum is 800mg in divided doses daily. If patient cannot tolerate this regimen, lower doses should he used with longer intervals between increases. Children, aged 2 to 16 years, start with 25mg at night then increase every 1 to 2 weeks by 1 to 3mg per kg of body weight each day until lowest effective dose to achieve control is reached. The usual maintenance dose is in the order of 5 to 9mg per kg of body weight each day in 2 divided doses. Topramax Sprinkle can be swallowed as it is or mixed with soft food that does not require chewing.

Special Care

Pregnancy, impaired kidneys, patients at risk of kidney stones. Patients should drink plenty of fluids and drug should be gradually withdrawn.

Avoid Use

Breastfeeding.

Possible Drug and Food Interactions

Oral contraceptives, phenytoin, agents which may cause kidney stones, digoxin, carbamazepine.

Known Side Effects

Confusion, difficulty in concentrating, double vision, dizziness, weakness, loss of co-ordination, weariness, sleepiness, problems with memory and speech, numbness/tingling/'pins and needles' sensation, pains in abdomen, anorexia, involuntary eye movements, psychomotor slowness. In rare cases, acute shortsightedness with glaucoma - drug should be stopped and patient referred to eye specialist.