Neurontin 300 - each capsule contains 300mg gabapentin. Neurontin 400 - each capsule contains 400mg gabapentin. In vitro animal studies with radiolabeled gabapentin have characterized a peptide binding site in brain tissues including neocortex and hippocampus that may relate to anticonvulsant activity of gabapentin and its structural derivatives. However the mechanism of action remains unclear. Pharmacokinetics and Metabolism Following oral administration, peak plasma gabapentin concentrations are observed within 2 to 3 hours.
Food has no effect on gabapentin pharmacokinetics.
Gabapentin elimination parameters are independent of dose. However, the extent of gabapentin absorption decreases with increasing dose. In normal volunteers the elimination half-life of gabapentin is independent of dose and averages 5 to 7 hours. Gabapentin is not bound to plasma proteins and has an apparent volume of distribution of 57,7 liters. Gabapentin is eliminated solely by renal excretion.