DOSAGE AND ADMINISTRATION (SEE TABLE BELOW) Carbamazepine suspension in combination with liquid chlorpromazine or thioridazine results in precipitate formation, and, in the case of chlorpromazine, there has been a report of a patient passing an orange rubbery precipitate in the stool following coadministration of the two drugs (see PRECAUTIONS, Drug Interactions). Because the extent to which this occurs with other liquid medications is not known, carbamazepine suspension should not be administered simultaneously with other liquid medications or diluents. Monitoring of blood levels has increased the efficacy and safety of anticonvulsants (see PRECAUTIONS, Laboratory Tests). Dosage should be adjusted to the needs of the individual patient. A low initial daily dosage with a gradual increase is advised. As soon as adequate control is achieved, the dosage may be reduced very gradually to the minimum effective level. Medication should be taken with meals. Since a given dose of carbamazepine suspension will produce higher peak levels than the same dose given as the tablet, it is recommended to start with low doses (children 6 to 12 years: ½ teaspoon four times a day) and to increase slowly to avoid unwanted side effects. Conversion of patients from oral carbamazepine tablets to carbamazepine suspension: Patients should be converted by administering the same number of mg per day in smaller, more frequent doses (i.e., twice a day tablets to three times a day suspension). Carbamazepine extended-release tablets are an extended-release formulation for twice a day administration. When converting patients from carbamazepine conventional tablets to carbamazepine extended-release tablets, the same total daily mg dose of carbamazepine extended-release should be administered. Carbamazepine extended-release tablets must be swallowed whole and never crushed or chewed. Carbamazepine extended-release tablets should be inspected for chips or cracks. Damaged tablets, or tablets without a release portal, should not be consumed. Carbamazepine extended-release tablet coating is not absorbed and is excreted in the feces; these coatings may be noticeable in the stool. Epilepsy (SEE INDICATIONS AND USAGE) Adults and children over 12 years of age-Initial: Either 200 mg twice a day for tablets and extended-release tablets, or 1 teaspoon four times a day for suspension (400 mg/day). Increase at weekly intervals by adding up to 200 mg/day using a twice a day regimen of carbamazepine extended-release tablets or a three times a day or four times a day regimen of the other formulations until the optimal response is obtained. Dosage generally should not exceed 1000 mg daily in children 12 to 15 years of age, and 1200 mg daily in patients above 15 years of age. Doses up to 1600 mg daily have been used in adults in rare instances. Maintenance: Adjust dosage to the minimum effective level, usually 800 to 1200 mg daily. Children 6 to 12 years of age-Initial: Either 100 mg twice a day for tablets or extended-release tablets, or ½ teaspoon four times a day for suspension (200 mg/day). Increase at weekly intervals by adding up to 100 mg/day using a twice a day regimen of carbamazepine extended-release tablets or a three times a day or four times a day regimen of the other formulations until the optimal response is obtained. Dosage generally should not exceed 1000 mg daily. Maintenance: Adjust dosage to the minimum effective level, usually 400 to 800 mg daily. Children under 6 years of age-Initial: 10 to 20 mg/kg/day twice a day or three times a day as tablets, or four times a day as suspension. Increase weekly to achieve optimal clinical response administered three times a day or four times a day. Maintenance: Ordinarily, optimal clinical response is achieved at daily doses below 35 mg/kg. If satisfactory clinical response has not been achieved, plasma levels should be measured to determine whether or not they are in the therapeutic range. No recommendation regarding the safety of carbamazepine for use at doses above 35 mg/kg/24 hours can be made. Combination Therapy: Carbamazepine may be used alone or with other anticonvulsants. When added to existing anticonvulsant therapy, the drug should be added gradually while the other anticonvulsants are maintained or gradually decreased, except phenytoin, which may have to be increased (see PRECAUTIONS, Drug Interactions, and Pregnancy). Trigeminal Neuralgia (SEE INDICATIONS AND USAGE) Initial: On the first day, either 100 mg twice a day for tablets or extended-release tablets, or ½ teaspoon four times a day for suspension, for a total daily dose of 200 mg. This daily dose may be increased by up to 200 mg/day using increments of 100 mg every 12 hours for tablets or extended-release tablets, or 50 mg (½ teaspoon) four times a day for suspension, only as needed to achieve freedom from pain. Do not exceed 1200 mg daily. Maintenance: Control of pain can be maintained in most patients with 400 to 800 mg daily. However, some patients may be maintained on as little as 200 mg daily, while others may require as much as 1200 mg daily. At least once every 3 months throughout the treatment period, attempts should be made to reduce the dose to the minimum effective level or even to discontinue the drug. Dosage Information Initial Dose Subsequent Dose Maximum Daily Dose Indication Tablet* Extended-Release Tablets Suspension Tablet* Extended-Release Tablets Suspension Tablet* Extended-Release Tablets Suspension Epilepsy Under 6 yr 10-20 mg/kg/day twice a day or 3 times a day 10-20 mg/kg/day 4 times a day Increase weekly to achieve optimal clinical response, 3 times a day or 4 times a day Increase weekly to achieve optimal clinical response, 3 times a day or 4 times a day 35 mg/ kg/24 hr (see Dosage and Administration section above) 35 mg/kg/ 24 hr (see Dosage and Administration section above) 6-12 yr 100 mg twice a day (200 mg/day) 100 mg twice a day (200 mg/day) ½ tsp 4 times a day (200 mg/day) Add up to 100 mg/day at weekly intervals, 3 times a day or 4 times a day Add 100 mg/day at weekly intervals, twice a day Add up to 1tsp (100 mg)/day at weekly intervals, 3 times a day or 4 times a day 1000 mg/ 24 hr Over 12 yr 200 mg twice a day (400 mg/day) 200 mg twice a day (400 mg/day) 1 tsp 4 times a day (400 mg/day) Add up to 200 mg/day at weekly intervals, 3 times a day or 4 times a day Add up to 200 mg/day at weekly intervals, twice a day Add up to 2 tsp (200 mg)/day at weekly intervals, 3 times a day or 4 times a day 1000 mg/24 hr (12-15 yr) 1200 mg/24 hr (>15 yr) 1600 mg/24 hr (adults, in rare instances) Trigeminal Neuralgia 100 mg twice a day (200 mg/day) 100 mg twice a day (200 mg/day) ½ tsp 4 times a day (200 mg/day) Add up to 200 mg/day in increments of 100 mg every 12 hr Add up to 200 mg/day in increments of 100 mg every 12 hr Add up to 2 tsp (200 mg)/day in increments of 50 mg (½ tsp) 4 times a day 1200 mg/ 24 hr *Tablet = Chewable or conventional tablets