Felbamate exerts its therapeutic effects through multiple mechanisms, which contribute to its efficacy in treating epilepsy. Its key mechanisms include:

1. Modulation of GABAergic Activity:
   • Felbamate enhances the activity of gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter in the brain, by increasing GABA-A receptor-mediated chloride currents.
   • This enhances neuronal inhibition, reducing seizure activity.
2. Blockade of NMDA Receptors:
   • Felbamate blocks N-methyl-D-aspartate (NMDA) receptors, reducing the excitatory effects of glutamate.
   • This action helps prevent the spread of seizure activity in the brain.
3. Sodium Channel Blockade:
   • Felbamate inhibits voltage-gated sodium channels, stabilizing neuronal membranes and preventing the repetitive firing of action potentials.
4. Calcium Channel Modulation:
   • Felbamate may also inhibit high-voltage-activated calcium channels, further contributing to its anticonvulsant properties.

Felbamate is approved for specific clinical conditions, including:

1. Epilepsy:
   • Adjunctive therapy for focal (partial) seizures with or without secondary generalization in adults.
   • Treatment of generalized seizures associated with Lennox-Gastaut syndrome in children and adults.
2. Off-Label Uses:
   • Treatment of refractory epilepsy (when other medications have failed).

The dosage of felbamate varies depending on the indication, patient age, and clinical response. The following dosing guidelines are based on the British National Formulary (BNF) and clinical pharmacology references:

1. Adults:
   • Adjunctive Therapy: Start with 1200 mg daily in divided doses, increasing by 600 mg weekly to a maintenance dose of 2400–3600 mg daily in divided doses.
   • Monotherapy: Start with 1200 mg daily in divided doses, increasing by 600 mg weekly to a maintenance dose of 3600–4800 mg daily in divided doses.
2. Children (2–14 years):
   • Adjunctive Therapy: Start with 15 mg/kg/day in divided doses, increasing by 15 mg/kg weekly to a maintenance dose of 45–60 mg/kg/day in divided doses.

Important Considerations:

• Felbamate is available in oral tablets and oral suspension.
• Dose adjustments may be necessary for patients with hepatic or renal impairment.
• Therapeutic drug monitoring is not routinely required but may be useful in certain cases.

Felbamate is associated with a range of side effects, some of which can be serious. Common side effects include:

1. Central Nervous System:
   • Dizziness, headache, and insomnia.
   • Cognitive impairment and behavioral changes.
2. Gastrointestinal:
   • Nausea, vomiting, and anorexia.
3. Other:
   • Fatigue, weight loss, and rash.

Serious Side Effects:

• Aplastic Anemia: A rare but life-threatening condition characterized by a reduction in red blood cells, white blood cells, and platelets.
• Liver Failure: Felbamate can cause severe hepatotoxicity, requiring regular monitoring of liver function tests.
• Suicidal Thoughts: Like other anticonvulsants, felbamate may increase the risk of suicidal thoughts or behavior.

Felbamate requires careful monitoring and adherence to specific precautions to ensure patient safety:

1. Hematological Monitoring:
   • Regular monitoring of blood counts is essential to detect early signs of aplastic anemia.
2. Hepatic Monitoring:
   • Regular monitoring of liver function tests is essential to detect early signs of hepatotoxicity.
3. Pregnancy and Lactation:
   • Felbamate should be used during pregnancy only if the potential benefits outweigh the risks. It is excreted in breast milk, so breastfeeding is generally not recommended.
4. Elderly Patients:
   • Lower doses may be required due to increased sensitivity to side effects, particularly cognitive impairment and dizziness.
5. Suicidal Risk:
   • Monitor for worsening depression or suicidal thoughts, particularly in patients with mood disorders.

Felbamate has a significant potential for drug interactions due to its effects on hepatic enzymes. Key interactions include:

1. CYP3A4 Inducers:
   • Carbamazepine and phenytoin can decrease felbamate levels, reducing its efficacy.
2. CYP3A4 Inhibitors:
   • Ketoconazole and erythromycin can increase felbamate levels, increasing the risk of side effects.
3. Other Anticonvulsants:
   • Felbamate can increase the levels of phenytoin and valproic acid, increasing the risk of toxicity.
4. Oral Contraceptives:
   • Felbamate reduces the efficacy of hormonal contraceptives by increasing their metabolism.
5. Other Interactions:
   • Warfarin: Felbamate can alter anticoagulant effects.
   • Theophylline: Felbamate can reduce its levels.

Felbamate is the generic name for this medication. It is marketed under various brand names, depending on the country and manufacturer. Some examples include:

• Felbatol (a well-known brand in the United States and other regions).
• Felbamate Accord.

Felbamate Mylan