Vigabatrin for refractory complex partial seizures: multicenter single-blind study with long-term follow-up

Area of Science:

• Neurology
• Pharmacology

Background:

• Complex partial seizures (CPS) are often refractory to standard antiepileptic drugs.
• Vigabatrin (VGB), an irreversible GABA transaminase inhibitor, is a potential treatment option for drug-resistant epilepsy.

Purpose of the Study:

• To evaluate the efficacy and tolerability of vigabatrin (VGB) as an add-on therapy for patients with complex partial seizures (CPS) refractory to conventional treatments.
• To assess the long-term safety and maintenance of seizure control with VGB.

Main Methods:

• A single-blind study involving 89 patients with refractory CPS.
• Patients received VGB as add-on therapy, with seizure frequency and side effects monitored.
• A subset of responders was followed for long-term efficacy and safety.

Main Results:

• VGB significantly reduced the median monthly CPS frequency from 11.0 to 5.0 (p < 0.001).
• 51% of patients experienced a ≥50% decrease in CPS frequency.
• Most side effects were transient; 74% of patients warranted continued VGB therapy based on efficacy:toxicity ratio.
• Long-term follow-up showed sustained seizure control and no serious systemic or neurologic toxicity.
• VGB coadministration decreased phenytoin serum concentration by a mean of 20% (p < 0.001).

Conclusions:

• Vigabatrin is an effective add-on treatment for drug-resistant complex partial seizures.
• VGB offers a favorable efficacy:toxicity profile for long-term management of refractory epilepsy.
• Patients can maintain seizure control with VGB, though monitoring for drug interactions like with phenytoin is necessary.