Long-term Effectiveness of Antiepileptic Drug Monotherapy in Partial Epileptic Patients: A 7-year Study in an Epilepsy Center in China

Abstract

Background: It is important to choose an appropriate antiepileptic drug (AED) to manage partial epilepsy. Traditional AEDs, such as carbamazepine (CBZ) and valproate (VPA), have been proven to have good therapeutic effects. However, in recent years, a variety of new AEDs have increasingly been used as first-line treatments for partial epilepsy. As the studies regarding the effectiveness of new drugs and comparisons between new AEDs and traditional AEDs are few, it is determined that these are areas in need of further research. Accordingly, this study investigated the long-term effectiveness of six AEDs used as monotherapy in patients with partial epilepsy.

Methods: This is a retrospective, long-term observational study. Patients with partial epilepsy who received monotherapy with one of six AEDs, namely, CBZ, VPA, topiramate (TPM), oxcarbazepine (OXC), lamotrigine (LTG), or levetiracetam (LEV), were identified and followed up from May 2007 to October 2014, and time to first seizure after treatment, 12-month remission rate, retention rate, reasons for treatment discontinuation, and adverse effects were evaluated.

Results: A total of 789 patients were enrolled. The median time of follow-up was 56.95 months. CBZ exhibited the best time to first seizure, with a median time to first seizure of 36.06 months (95% confidential interval: 30.64-44.07). CBZ exhibited the highest 12-month remission rate (85.55%), which was significantly higher than those of TPM (69.38%, P = 0.006), LTG (70.79%, P = 0.001), LEV (72.54%, P = 0.005), and VPA (73.33%, P = 0.002). CBZ, OXC, and LEV had the best retention rate, followed by LTG, TPM, and VPA. Overall, adverse effects occurred in 45.87% of patients, and the most common adverse effects were memory problems (8.09%), rashes (7.76%), abnormal hepatic function (6.24%), and drowsiness (6.24%).

Conclusion: This study demonstrated that CBZ, OXC, and LEV are relatively effective in managing focal epilepsy as measured by time to first seizure, 12-month remission rate, and retention rate.

Figure 1

Study flow diagram. CBZ: Carbamazepine; VPA: Valproate; TPM: Topiramate; OXC: Oxcarbazepine; LTG: Lamotrigine; LEV: Levetiracetam.

Figure 2

Time to first seizure. CBZ: Carbamazepine; VPA: Valproate; TPM: Topiramate; OXC: Oxcarbazepine; LTG: Lamotrigine; LEV: Levetiracetam.

Figure 3

Twelve-month remission rates of six antiepileptic drugs (AEDs). CBZ: Carbamazepine; VPA: Valproate; TPM: Topiramate; OXC: Oxcarbazepine; LTG: Lamotrigine; LEV: Levetiracetam.

Figure 4

Long-term retention rates of six antiepileptic drugs. CBZ: Carbamazepine; VPA: Valproate; TPM: Topiramate; OXC: Oxcarbazepine; LTG: Lamotrigine; LEV: Levetiracetam.