Topamax Dosage/Direction for Use

It is not necessary to monitor topiramate plasma concentrations to optimize therapy with TOPAMAX. On rare occasions, the addition of TOPAMAX to phenytoin may require an adjustment of the dose of phenytoin to achieve optimal clinical outcome. Addition or withdrawal of phenytoin and carbamazepine to adjunctive therapy with TOPAMAX may require adjustment of the dose of TOPAMAX.
Dosage: It is recommended that therapy be initiated at a low dose followed by titration to an effective dose.
Epilepsy - adjunctive therapy: Adults: Therapy should begin at 25 to 50 mg nightly for one week. Use of lower initial doses has been reported, but has not been studied systematically. Subsequently, at weekly or bi-weekly intervals, the dose should be increased by 25 to 50 [to 100] mg/day and taken in two divided doses. Dose titration should be guided by clinical outcome. Some patients may achieve efficacy with once-a-day dosing.
In clinical trials as adjunctive therapy, 200 mg was effective and was the lowest dosage studied. This is therefore considered the minimum effective dose. The usual daily dose is 200 to 400 mg in two divided doses. Individual patients have received doses as high as 1600 mg/day.
These dosing recommendations apply to all adults, including the elderly, in the absence of underlying renal disease (see Renal impairment under Precautions).
Children aged 2 and above: The recommended total daily dose of TOPAMAX as adjunctive therapy is approximately 5 to 9 mg/kg/day in two divided doses. Titration should begin at 25 mg (or less, based on a range of 1 to 3 mg/kg/day) nightly for the first week. The dosage should then be increased at 1- or 2-week intervals by increments of 1 to 3 mg/kg/day (administered in two divided doses), to achieve optimal clinical response. Dose titration should be guided by clinical outcome.
Daily doses up to 30 mg/kg/day have been studied and were generally well tolerated.
Epilepsy - monotherapy: When concomitant antiepileptic drugs (AEDs) are withdrawn to achieve monotherapy with topiramate, consideration should be given to the effects this may have on seizure control. Unless safety concerns require an abrupt withdrawal of the concomitant AED, a gradual discontinuation at the rate of approximately one-third of the concomitant AED dose every 2 weeks is recommended (see Withdrawal of TOPAMAX under Precautions).
When enzyme inducing drugs are withdrawn, topiramate levels will increase. A decrease in TOPAMAX dosage may be required if clinically indicated.
Adults: Titration should begin at 25 mg nightly for 1 week. The dosage should then be increased at 1- or 2-week intervals by increments of 25 or 50 mg/day, administered in two divided doses. If the patient is unable to tolerate the titration regimen, smaller increments or longer intervals between increments can be used. Dose and titration rate should be guided by clinical outcome.
The recommended initial target dose for topiramate monotherapy in adults is 100 mg/day and the maximum recommended daily dose is 500 mg. Some patients with refractory forms of epilepsy have tolerated topiramate monotherapy at doses of 1000 mg/day. These dosing recommendations apply to all adults including the elderly in the absence of underlying renal disease.
Children aged 2 and above: Treatment of children aged 2 years and above should begin at 0.5 to 1 mg/kg nightly for the first week. The dosage should then be increased at 1- or 2- week intervals by increments of 0.5 to 1 mg/kg/day, administered in two divided doses. If the child is unable to tolerate the titration regimen, smaller increments or longer intervals between dose increments can be used. Dose and dose titration rate should be guided by clinical outcome.
The recommended initial target dose range for topiramate monotherapy in children aged two years and above is 3 to 6 mg/kg/day. Children with recently diagnosed partial onset seizures have received doses of up to 500 mg/day.
Migraine: Adults: The recommended total daily dose of topiramate for prophylaxis of migraine headache is 100 mg/day administered in two divided doses. Titration should begin at 25 mg nightly for 1 week. The dosage should then be increased in increments of 25 mg/day administered at 1-week intervals. If the patient is unable to tolerate the titration regimen, longer intervals between dose adjustments can be used.
Some patients may experience a benefit at a total daily dose of 50 mg/day. Patients have received a total daily dose up to 200 mg/day. Dose and titration rate should be guided by clinical outcome (see Pharmacology: Pharmacodynamics: Migraine clinical trials under Actions).
Special populations: Renal impairment: Patients with moderate and severe renal impairment (CL_CR <70 mL/min) may require a dose reduction. Half of the usual starting and maintenance dose is recommended (see Pharmacology: Pharmacokinetics: Special populations: Renal impairment under Actions).
Since TOPAMAX is removed from plasma by hemodialysis, a supplemental dose of TOPAMAX equal to approximately one-half the daily dose should be administered on hemodialysis days. The supplemental dose should be administered in divided doses at the beginning and completion of the hemodialysis procedure. The supplemental dose may differ based on the characteristics of the dialysis equipment being used (see Pharmacology: Pharmacokinetics: Special populations: Renal impairment under Actions).
Hepatic impairment: Topiramate should be administered with caution in patients with hepatic impairment (see Pharmacology: Pharmacokinetics: Special populations: Hepatic impairment under Actions).
Administration: TOPAMAX is available in tablets formulation, for oral administration. It is recommended that TOPAMAX tablets not be broken.
TOPAMAX can be taken without regard to meals.