Zefretol 400 Tablet contains Eslicarbazepine 400 mg, an anticonvulsant medication primarily indicated for the treatment of partial-onset seizures in adults and pediatric patients aged six years and older. Eslicarbazepine acts by stabilizing hyperexcited neuronal membranes and inhibiting repetitive neuronal firing through modulation of voltage-gated sodium channels, thereby reducing seizure activity. Zefretol 400 is typically administered orally once daily, with or without food, to maintain steady plasma concentrations and optimize therapeutic efficacy. Dosage adjustments may be necessary based on clinical response and tolerability, particularly in patients with renal impairment or those receiving concomitant antiepileptic drugs. Common adverse effects include dizziness, somnolence, headache, nausea, and diplopia, which are generally mild to moderate and transient. Caution is advised in patients with a history of hypersensitivity to carbamazepine or oxcarbazepine, as cross-reactivity may occur. Regular monitoring of electrolytes, liver function, and hematological parameters is recommended during therapy. Zefretol 400 should be used under strict medical supervision, with gradual dose titration to minimize adverse effects and ensure optimal seizure control. It is contraindicated in patients with hypersensitivity to Eslicarbazepine or related compounds.