Lennox-Gastaut%252525252525252525252525252525252525252525252520syndrome

# Lennox-Gastaut Syndrome (LGS) ## Overview Lennox-Gastaut Syndrome (LGS) is a severe, rare form of epilepsy that begins in early childhood, characterized by a combination of frequent, severe seizures, intellectual disability, and specific EEG findings (slow spike-and-wave pattern). It is often drug-resistant. ## Primary Indications Adjunctive therapy for seizures associated with Lennox-Gastaut Syndrome (LGS) in patients 2 years of age and older. ## Adult Dosing * **Cannabidiol (CBD) Oral Solution:** * Starting dose: 2.5 mg/kg twice daily (5 mg/kg/day total). * Titration: Increase dose every 2 weeks by 2.5 mg/kg, twice daily (5 mg/kg/day). * Maintenance: Doses up to 10 mg/kg twice daily (20 mg/kg/day total) have shown efficacy. * Maximum dose: 20 mg/kg/day. * **Clobazam:** * Starting dose: 5 mg twice daily. * Titration: Increase dose weekly as needed. * Maintenance dose: Typically 10-20 mg twice daily. * Maximum dose: 20 mg twice daily (40 mg/day total). * **Felbamate:** * Starting dose: 15 mg/kg/day divided into three doses. * Titration: Increase dose every 2 weeks as tolerated, up to 45 mg/kg/day. * Maximum dose: 45 mg/kg/day or 3600 mg/day, whichever is less. * **Topiramate:** * Starting dose: 1 mg/kg/day or 25 mg at bedtime. * Titration: Increase dose weekly by 1-3 mg/kg/day, divided into two doses. * Maintenance: 3-9 mg/kg/day divided into two doses. * Maximum dose: 12 mg/kg/day or 400 mg/day, whichever is less. * **Vigabatrin:** * Starting dose: 50 mg/kg/day divided into two doses. * Titration: Increase dose weekly as tolerated. * Maintenance: Up to 100 mg/kg/day divided into two doses. * Maximum dose: 100 mg/kg/day or 3000 mg/day, whichever is less. Dosing for other antiepileptic drugs used adjunctively for LGS depends on the specific agent and local protocols; refer to individual drug monographs. ## Pediatric Dosing * **Cannabidiol (CBD) Oral Solution:** * Starting dose: 2.5 mg/kg twice daily (5 mg/kg/day total) for patients 2 years of age and older. * Titration and maintenance doses are the same as adults, adjusted for weight. * Maximum dose: 20 mg/kg/day. * **Clobazam:** * Starting dose: 5 mg once daily for patients <20 kg; 5 mg twice daily for patients >=20 kg. * Titration and maintenance doses are the same as adults, adjusted for weight. * Maximum dose: 20 mg twice daily (40 mg/day total). * **Felbamate:** * Starting dose: 15 mg/kg/day divided into three doses. * Titration and maintenance doses are the same as adults, adjusted for weight. * Maximum dose: 45 mg/kg/day or 3600 mg/day, whichever is less. * **Topiramate:** * Starting dose: 1 mg/kg/day or 25 mg at bedtime. * Titration and maintenance doses are the same as adults, adjusted for weight. * Maximum dose: 12 mg/kg/day or 400 mg/day, whichever is less. * **Vigabatrin:** * Starting dose: 50 mg/kg/day divided into two doses. * Titration and maintenance doses are the same as adults, adjusted for weight. * Maximum dose: 100 mg/kg/day or 3000 mg/day, whichever is less. Dosing for other antiepileptic drugs used adjunctively for LGS depends on the specific agent and local protocols; refer to individual drug monographs. ## Dose Adjustments * **Hepatic Impairment:** Dose reduction may be necessary for CBD, Clobazam, Felbamate, and Topiramate. Consult specific product information. Vigabatrin has no specific dose adjustment recommendations for hepatic impairment, but caution is advised. * **Renal Impairment:** Dose reduction may be necessary for CBD, Clobazam, Felbamate, and Topiramate, particularly with severe impairment. Consult specific product information. Vigabatrin has no specific dose adjustment recommendations for renal impairment, but caution is advised. ## Contraindications * **Cannabidiol:** Hypersensitivity to CBD. * **Clobazam:** History of hypersensitivity to Clobazam. * **Felbamate:** Co-administration with drugs known to induce or inhibit hepatic drug-metabolizing enzymes, especially those in the CYP450 family. History of bone marrow suppression or toxic/idiosyncratic reaction to previous Felbamate administration. Aplastic anemia or significant hepatic dysfunction. * **Topiramate:** Co-administration with or within 14 days of treatment with metformin. * **Vigabatrin:** Hypersensitivity to Vigabatrin. ## Adverse Effects Common adverse effects include somnolence, fatigue, decreased appetite, diarrhea, vomiting, upper respiratory tract infections (especially for CBD), behavioral changes, and weight gain. Serious adverse effects include suicidal behavior and ideation, hepatic transaminase elevations (Felbamate, CBD), potential for aplastic anemia and hepatic toxicity (Felbamate