The cost effectiveness of zonisamide as adjunctive therapy in adult partial seizure epilepsy

Summary

Many patients with epilepsy continue to have partial seizures requiring add-on antiepileptic drugs (AEDs). Zonisamide, a broad-spectrum AED, has recently entered the European market and must be compared with the current standard of care. The objective of this study was to determine the cost effectiveness of zonisamide as treatment for adults with uncontrolled partial epilepsy in Scotland. A Markov decision model was developed from the perspective of the Scottish National Health Service. Outcome measures included quality-adjusted life-years (QALYs) and costs in GBP.

Patients treated with zonisamide had a 15-year incremental cost of £20 and 0.026 additional QALYs compared with patients treated with levetiracetam. These modest differences result in an incremental cost-effectiveness ratio for zonisamide of £761/QALY.

We conclude that zonisamide is a cost-effective treatment for adult patients with refractory partial epilepsy being treated according to Scottish treatment patterns and costs, assuming a willingness to pay of £20,000/QALY.

Keywords: :

• cost effectiveness
• epilepsy
• quality-adjusted life-years
• partial seizures
• utilities