Tiagabine for complex partial seizures: a randomized, add-on, dose-response trial

Area of Science:

• Neurology
• Pharmacology

Background:

• Complex partial seizures (CPS) are a common form of epilepsy.
• Current treatments for intractable CPS have limitations.
• Tiagabine is an antiepileptic drug (AED) that inhibits gamma-aminobutyric acid (GABA) uptake.

Purpose of the Study:

• To evaluate the efficacy and tolerability of tiagabine as adjunctive therapy for patients with intractable CPS.
• To compare three different doses of tiagabine against a placebo.

Main Methods:

• A randomized, double-blind, placebo-controlled study was conducted across 21 US medical centers.
• 297 patients with CPS, on stable antiepileptic drug regimens, received either placebo or tiagabine (16, 32, or 56 mg daily) for 20 weeks.
• The primary outcome measure was the median change in 4-week CPS frequency.

Main Results:

• Significant reductions in CPS frequency were observed with tiagabine at 32 mg (-2.2) and 56 mg (-2.8) compared to placebo (-0.7).
• A 50% or greater reduction in CPS frequency was achieved by 20% (32 mg) and 29% (56 mg) of patients, versus 4% in the placebo group.
• Adverse events were generally similar, with increased dizziness, tremor, abnormal thinking, and depressed mood noted at specific tiagabine doses.

Conclusions:

• Tiagabine is an effective and well-tolerated adjunctive treatment for patients with intractable complex partial seizures.
• A clear dose-response relationship was established for tiagabine in treating CPS.
• Further research may explore optimal dosing strategies and long-term outcomes.