Abstract
BACKGROUND: Epilepsy affects approximately 50 million people worldwide. Antiepileptic drugs (AEDs) are the mainstream treatment. Therapeutic drug monitoring (TDM) of AEDs is necessary to maximize efficacy and minimize toxicity. We report a simple, rapid, and cost-effective ultra-performance liquid chromatography-mass spectrometry method that can simultaneously measure seven AEDs/metabolites, including levetiracetam (LEV), lacosamide (LCM), zonisamide (ZON), lamotrigine (LMT), 10-hydroxycarbazepine (OXC-M1), clobazam (CLO), and N-desmethyl clobazam (N-CLB) in serum. METHOD: Only 20 µl of serum was used with simple protein precipitation and dilution. Analysis was performed on a SCIEX 6500 UHPLC-MS/MS in positive ion mode. Separation was performed on a C18 reversed-phase column using a gradient. The seven AEDs/metabolites were eluted in 4.5 min. RESULTS: The assay was linear over the concentration ranges 0.4-100 µg/mL for LEV, 0.12-30 µg/mL for LMT, 0.12-30 µg/mL for LCM, 0.32-80 µg/mL for ZON, 0.28-70 µg/mL for OXC-M1, and 7.82-2000 ng/mL for CLO, 78.2-20000 ng/mL for N-CLB, respectively, with correlation coefficient greater than 0.99. Recovery was from 88 to 108 %. Intra and inter assay precision for three levels of quality controls were from 2.1 to 6.8 % and 4.2 to 10.9 %, respectively. The accuracy was evaluated by comparing with the College of American Pathologists survey results, and a correlation coefficient greater than 0.96 was observed. The absence of matrix effects was also confirmed. CONCLUSION: We have developed and validated a simple, rapid, and cost-effective UHPLC-MS/MS method for the simultaneous quantitation of seven AEDs/metabolites in serum within a 4.5-min analysis time. It has been implemented in our children's hospital with same-day turnaround time.