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Felbamate level

Lab Section:  Sendout Reference  
Lab Location:  Sendout
Reference Lab: Mayo 
Test ID: LAB686 
Synonyms: Felbatol
Methodology: High Turbulence Liquid Chromatography-Tandem Mass Spectrometry (HTLC-MS/MS)
Schedule: Daily
Reported: 5 days
Specimen Requirements:  Collection: 3.0 mL Blood in a Red Top Tube.
Pediatric volume: 1 mL.
Serum; Plain, red-top tube(s); serum gel also acceptable.
Handling: Draw specimen immediately before next scheduled dose..
Unacceptable conditions: Specimens other than serum; Gross hemolysis, Gross lipemia
Stability: Refrigerated (preferred): 28 days; Ambient 28 days; Frozen: 28 days


Clinical Indications: Felbamate is an anticonvulsant drug approved for treatment of partial seizures with or without secondary generalization in persons >14 years of age. It is also approved for Lennox-Gastout syndrome in children >2 years of age. Felbamate is well absorbed (>90%) and is metabolized by the hepatic cytochrome P450 system. Metabolites lack anticonvulsant activity. The elimination half-life of felbamate ranges from 13 to 23 hours. Optimal response to felbamate is seen with serum concentrations between 30 mcg/mL to 60 mcg/mL. Patients who are elderly or have renal dysfunction may require reduced dosing; felbamate should not be given to individuals with hepatic disease. Toxicity can be severe, including life-threatening aplastic anemia or liver failure, but no defined toxic concentration has been established.

Reference Interval:  See patient report or consult reference laboratory website.
CPT Code(s): 80299
Last Changed: 12/06/2016 10:15:09
Last Reviewed: 12/06/2016 10:15:48