Rapid high-performance liquid chromatographic determination of serum gabapentin

Gabapentin (GBP) is a new antiepileptic drug approved for clinical treatment of partial seizures in the USA. Serum GBP concentrations in 283 patients were studied using high-performance liquid chromatography with fluorescence detection. The standard curves were linear over a range of 60 ng to 15 mu g/ml. The coefficient of variations were 3.4 to 8.8% and 1.4 to 9.8% for intra- and inter-assay studies, respectively. The lower limit of quantitation was 10 ng/ml. Of the 283 patients studied, 72.5% had GBP levels between 2 and 10 mu g/ml, 14.8% were below 2 mu g/ml and 12.7% above 10 mu g/ml. The mean+/-S.E. of GBP in 283 patients was 5.38+/-0.23 mu g/ml. Peak concentrations of more than 15 mu g/ml and trough levels as low as 0.1 mu g/ml were not uncommon. The method described was rapid, simple, highly sensitive and reproducible. Other antiepileptic drugs and endogenous compounds did not interfere with the assay. (C) 1999 Elsevier Science BN. All rights reserved.