1 mL serum or plasma from a Red Top, Lavender EDTA or Green Top Heparin tube. Do not collect in SST tube. Centrifuge and transfer separated serum or plasma to a transport tube, indicate the specimen type on the tube.
Draw just before next dose.
Room temp: 14 days, Refrigerated: 7 days, Frozen: 28 days
Antiepileptic therapeutic drug monitoring. Peak plasma levels are reached in about 2 hours after oral administration. Elimination half-life is 10-100 hours.