Generic Name

Felbamate

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Classification

FDA Approved Indications

• Adjunctive therapy for partial seizures in adults and children with epilepsy; Lennox-Gastaut syndrome in children aged 2 years and older

Mechanism of Action

The exact mechanism is not fully understood, but felbamate appears to enhance GABA-mediated inhibition and inhibit NMDA receptor activity, contributing to its anticonvulsant effects.

Dosage and Administration

Adult: Initial dose: 1200 mg/day divided in 2-4 doses; titrate gradually based on response and tolerability.

Pediatric: Start at lower doses, typically 15-20 mg/kg/day divided in 2-4 doses; titrate as tolerated.

Geriatric: Use with caution; start at lower doses due to potential for increased adverse effects.

Renal Impairment: Adjust dose based on severity of impairment.

Hepatic Impairment: Use with caution; no specific adjustments established.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed; crosses the placenta and blood-brain barrier.

Metabolism: Partially metabolized in the liver; some metabolites may be active.

Excretion: Primarily excreted unchanged in the urine.

Half Life: Approximately 8-19 hours.

Contraindications

• Known hypersensitivity to felbamate.
• Patients with hepatic impairment or history of hepatic disease.

Precautions

• Risk of aplastic anemia and hepatic failure; monitor liver function tests regularly.
• Use cautiously in patients with blood dyscrasias or a history of blood dyscrasias.
• Psychiatric adverse effects, including depression or agitation, should be monitored.

Adverse Reactions - Common

• Sedation, dizziness (Frequent)
• Nausea, vomiting (Common)

Adverse Reactions - Serious

• Aplastic anemia (Rare)
• Hepatotoxicity (Rare)
• Mood changes, depression, suicidal thoughts (Rare)

Drug-Drug Interactions

• Valproic acid (may increase felbamate levels),
• Other CNS depressants (additive sedation)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Patient/Family Teaching

• Do not abruptly discontinue without consulting healthcare provider.
• Report any signs of infection, fatigue, jaundice, or mood changes immediately.
• Use caution when operating machinery or driving until response is known.

Special Considerations

Black Box Warnings:

• Aplastic anemia and severe hepatic failure have been reported; use only when clearly indicated and monitor closely.

Genetic Factors: Genetic variation in drug metabolism may influence efficacy and toxicity.

Lab Test Interference: May interfere with certain laboratory tests related to blood and liver functions.

Overdose Management

Signs/Symptoms: Drowsiness, dizziness, vomiting, coma, or hepatic failure.

Treatment: Supportive care, monitor hepatic function and blood counts, provide symptomatic treatment as needed.

Storage and Handling

Storage: Store at room temperature away from moisture and light.

Stability: Stable under recommended storage conditions.