The Serum 10-Hydroxy-carbazepine test measures the levels of Oxcarbazepine, a newer antiepileptic drug. Upon oral administration, Oxcarbazepine is rapidly reduced by cytosolic aryl ketone reductases in the liver, forming 10-hydroxycarbazepine. Healthcare professionals use this test to detect the serum level, enabling them to determine the concentration/dose relationship and assess potential toxicity in chronically epileptic patients.