Trade Names:Felbatol- Tablets 400 mg- Tablets 600 mg- Suspension 600 mg/5 mL
May reduce seizure spread in generalized tonic-clonic or partial seizures and may increase seizure threshold in absence seizures.
Vd is about 756 mL/kg and the drug is 22% to 25% bound to plasma proteins.
About 40% to 50% is excreted unchanged in the urine.
About 40% is unidentified metabolites and conjugates and about 15% is parahydroxy-felbamate, 2-hydroxyfelbamate, and felbamate monocarbamate; none have significant anticonvulsant activity.
The t 1/ 2 is 20 to 23 h. Cl is about 30 mL/h/kg.
Decreased felbamate Cl and increased t 1/ 2 were associated with diminishing renal function.
Monotherapy or adjunctive therapy in treatment of partial seizures with and without generalization in epileptic adults. Adjunctive therapy in treatment of partial and generalized seizures associated with Lennox-Gastaut syndrome in children.
Hypersensitivity to felbamate or ingredients of this product; hypersensitivity reactions to other carbamates; history of any blood dyscrasia or hepatic dysfunction.
Because of reports of aplastic anemia, it has been recommended to stop use of this drug unless health care provider decides that withdrawal would cause greater risk.Initial MonotherapyAdults and Adolescents 14 yr of age and older
PO 1,200 mg/day in 3 or 4 divided doses; increase in 600 mg increments every 2 wk to 2,400 mg/day and then 3,600 mg/day if indicated.Conversion to MonotherapyAdults and Adolescents 14 yr of age and older Initial dose
PO 1,200 mg/day in 3 or 4 divided doses, reducing dose of other antiepileptic drugs by 1/ 3 . At wk 2, increase felbamate to 2,400 mg/day and at week 3, increase to 3,600 mg/day; continue to reduce dose of other antiepileptic drugs as indicated.Adjunctive TherapyAdults and adolescents 14 yr of age and older Initial dose
PO 1,200 mg/day in 3 or 4 divided doses; reduce original dose of other antiepileptic drugs by 20% to 33% for 1 wk. At week 2, increase felbamate to 2,400 mg/day and at week 3, increase to 3,600 mg/day if needed; reduce dosage of other antiepileptic drugs as clinically indicated.Children 2 to 14 yr of age with Lennox-Gastaut Syndrome
PO 15 mg/kg/day in 3 or 4 divided doses while reducing other antiepileptic drugs at least 20%. Increase felbamate by 15 mg/kg/day increments at weekly intervals up to 45 mg/kg/day; continue to reduce dosage of other antiepileptic drugs as needed.
Store at room temperature in tightly closed container away from excessive heat, direct sunlight, and moisture.
Felbamate may increase blood levels of phenytoin and valproic acid and decrease blood levels of carbamazepine. Phenytoin or carbamazepine may increase clearance of felbamate.
None well documented.
Insomnia; headache; anxiety; somnolence; dizziness; nervousness; tremor; abnormal gait; depression; paresthesia; ataxia; dry mouth; stupor; thinking abnormalities; emotional lability.
Acne; rash; pruritus.
Diplopia; abnormal vision; miosis; otitis media; rhinitis; sinusitis; taste perversion; pharyngitis.
Dyspepsia; vomiting; constipation; diarrhea; nausea; anorexia; abdominal pain; hiccoughs.
Urinary incontinence; intramenstrual bleeding; UTI.
Aplastic anemia; purpura; leukopenia.
Increased ALT and AST; acute liver failure.
Upper respiratory tract infection; coughing.
Fatigue; weight decrease; facial edema; fever; chest pain; pain; hypophosphatemia; myalgia.
Aplastic anemia associated with use. Risk 100-fold in felbamate-treated patients compared to untreated population. May be fatal. Use only in patients with severe epilepsy in which risk of aplastic anemia is acceptable.Hepatotoxicity
Acute liver failure reported with use, initiate use in patients with normal liver function.
Monitor ALT, AST, and bilirubin at baseline and at 1- to 2-wk intervals. Discontinue if AST or ALT increase is greater than or equal to 2 times the upper limit of normal.
Monitor for effectiveness; note any changes in seizure patterns and frequency.
Category C .
Excreted in breast milk.
Safety and efficacy not established other than for adjunctive therapy of Lennox-Gastaut syndrome.
Use caution and start with low doses. Clinical experience is limited.
Administer drug with caution to patients with prior hypersensitivity reactions to carbamates.
Drug may have carcinogenic potential.
Withdraw drug slowly to avoid increased seizure frequency.
8 cases of acute liver failure have occurred, including 4 deaths, in association with the use of felbamate. Evaluate patients prior to treatment initiation for evidence of pre-existing liver damage; avoid use in patients with pre-existing liver pathology. Immediately withdraw the drug in patients who develop lab findings indicating liver injury.
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