Which is the most cost-effective antiseizure medication for initial monotherapy for focal epilepsy?

OBJECTIVE

An increasing number of antiseizure medications (ASMs) are approved for monotherapy for focal epilepsy, but direct comparisons of the lifetime cost-effectiveness of all existing treatment strategies are lacking. This study aims to compare the cost-effectiveness of new ASMs and traditional ASMs as first-line monotherapy for newly diagnosed focal epilepsy.

METHOD

We used a Markov model to evaluate the lifetime cost-effectiveness of 10 ASMs in the treatment of focal epilepsy, with lacosamide (LCM) as a control, from the perspective of society in the United States. Effectiveness, cost data, and health state utilities were obtained from published literature. The cycle of the model is 6 months. Willingness to pay was defined as $150 000 per quality-adjusted life year (QALY). One-way and probabilistic sensitivity analyses were conducted to evaluate parameter uncertainty, and several scenario analyses were also conducted.

RESULTS

The base case analysis showed that carbamazepine (CBZ) was the least costly ASM and more effective than valproic acid (VPA), levetiracetam (LEV), gabapentin (GBP), topiramate (TPM), and lamotrigine (LTG) from an American social perspective. In contrast, oxcarbazepine (OXC), phenytoin (PHT), phenobarbitone (PHB), LCM, and zonisamide (ZNS) were more effective than CBZ, with incremental cost-effectiveness ratios of $334 703.50, $325 610.99, $3 037 148.62, $1 178 954.91, and $108 153 360.85/QALY, respectively. The traditional ASMs were ranked as CBZ, PHT, VPA, and PHB; the new ASMs were ranked as OXC, LEV, LCM, LTG, TPM, GBP, and ZNS. When generic drugs are used, PHT, OXC, and CBZ remain the three most cost-effective options.

SIGNIFICANCE

In terms of cost-effectiveness, CBZ monotherapy is the best option for newly diagnosed focal epilepsy, followed by OXC, PHT, VPA, LEV, PHB, LCM, LTG, TPM, GBP, and ZNS. Most traditional ASMs are more cost-effective than new ASMs; OXC is an exception.