DOSAGE AND ADMINISTRATION
VIMPAT may be taken with or without food.
When using VIMPAT oral solution, it is recommended that a calibrated measuring device be obtained and used. A household teaspoon or tablespoon is not an adequate measuring device. Healthcare providers should recommend a device that can measure and deliver the prescribed dose accurately, and provide instructions for measuring the dosage.
VIMPAT can be initiated with either oral or intravenous administration. The initial dose should be 50 mg twice daily (100 mg per day). VIMPAT can be increased at weekly intervals by 100 mg/day given as two divided doses up to the recommended maintenance dose of 200 to 400 mg/day, based on individual patient response and tolerability. In clinical trials, the 600 mg daily dose was not more effective than the 400 mg daily dose, and was associated with a substantially higher rate of adverse reactions. [see Clinical Studies
Switching from Oral to Intravenous Dosing
When switching from oral VIMPAT, the initial total daily intravenous dosage of VIMPAT should be equivalent to the total daily dosage and frequency of oral VIMPAT and should be infused intravenously over a period of 30 to 60 minutes. There is experience with twice daily intravenous infusion for up to 5 days.
Switching from Intravenous to Oral Dosing
At the end of the intravenous treatment period, the patient may be switched to VIMPAT oral administration at the equivalent daily dosage and frequency of the intravenous administration.
Compatibility and Stability
VIMPAT injection can be administered intravenously without further dilution or may be mixed with diluents. VIMPAT injection was found to be physically compatible and chemically stable when mixed with the following diluents for at least 24 hours and stored in glass or polyvinyl chloride (PVC) bags at ambient room temperature 15-30°C (59-86°F).
Sodium Chloride Injection 0.9% (w/v)
Dextrose Injection 5% (w/v)
Lactated Ringer's Injection
The stability of VIMPAT injection in other infusion solutions has not been evaluated. Product with particulate matter or discoloration should not be used.
Any unused portion of VIMPAT injection should be discarded.
Patients with Renal Impairment
No dose adjustment is necessary in patients with mild to moderate renal impairment. A maximum dose of 300 mg/day VIMPAT is recommended for patients with severe renal impairment [creatinine clearance (CLCR) ≤30mL/min] and in patients with endstage renal disease. VIMPAT is effectively removed from plasma by hemodialysis. Following a 4-hour hemodialysis treatment, dosage supplementation of up to 50% should be considered. In all renally impaired patients, the dose titration should be performed with caution. [see Use in Specific Populations
Patients with Hepatic Impairment
The dose titration should be performed with caution in patients with hepatic impairment. A maximum dose of 300 mg/day is recommended for patients with mild or moderate hepatic impairment.
VIMPAT use is not recommended in patients with severe hepatic impairment [see Use in Specific Populations
DOSAGE FORMS AND STRENGTHS
50 mg (pink), 100 mg (dark yellow), 150 mg (salmon), and 200 mg (blue) film-coated tablets
200 mg/20mL injection
10 mg/mL oral solution