Pharmacokinetic of Gabapentin 600 mg Tablet in Thai Healthy Subjects
Supeecha Wittayalertpanya MSc*, Sumana Chompootaweep MD*, Nongnuch Thaworn MSc*, Wondee Khemsri BSc*, Nantaporn Prompila MSc**, Nonlanee Sayankuldilok BSc**, Wasan Punyasang MSc***
Affiliation : * Department of Pharmacology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand ** Chula Pharmacokinetic Research Center, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand *** Clinical Epidemiology Unit, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
Background : Gabapentin is an antiepileptic drug. It is structurally similar to γ-aminobutyric acid (GABA), which crosses
the blood-brain barrier. Gabapentin is absorbed into the blood by the L-amino acid transport system. The oral bioavailability
of gabapentin displays dose-dependence. Plasma concentrations of gabapentin are not directly proportional to dose. Therefore,
pharmacokinetic of gabapentin is essential for patients who have to receive gabapentin 600 mg.
Objective : To investigate the pharmacokinetic of gabapentin 600 mg in Thai healthy subjects.
Material and Method: The present study was performed on 24 healthy Thai male subjects who received a single oral dose
of 600 mg gabapentin tablet. Serial blood samples were collected before and to 48 hours after drug administration. Plasma
gabapentin concentrations were determined by automated High Performance Liquid Chromatography (HPLC) with UV
detector after deproteinized with acetonitrile followed by derivatization with 1-fluoro-2,4-dinitrobenzene. The relevant
pharmacokinetic parameters were determined.
Results : The mean values of pharmacokinetic parameters (mean + SD) were 3.17 + 0.80 hour (1.5 to 5.0 hour) for
Tmax; 4,853.58 + 1,369.67 ng/ml for Cmax; 0.11 + 0.02 hour-1 for Kel; 6.62 + 1.87 hour (4.89 to 11.41 hour) for T1/2 ;
47,712.88 + 12,853.61 ng.hour/ml for AUC0-t, 48,713.20 + 12,909.78 ng.hour/ml for AUC0-inf, 5.24 + 1.32 L/hour for Cl,
and 49.28 + 15.98 L for Vd.
Conclusion : The data show the pharmacokinetic parameters of gabapentin 600 mg. These data should be used to support
the assignment of therapeutic purposes for patients who have to receive gabapentin 600 mg.
Keywords : Gabapentin, Pharmacokinetic
