Gabutin Mechanism of Action

Pharmacology: Pharmacodynamics: Gabapentin is structurally related to GABA (gamma-aminobutyric acid). However, it does not bind to GABA_A or GABA_B receptors. High affinity gabapentin binding sites have been located throughout the brain where correspond to the presence of voltage-gated calcium channels specifically possessing the alpha-2-delta-1 subunit. This channel appears to be located presynaptically, and may modulate the release of excitatory neurotransmitters which participate in epileptogenesis and nociception.
Pharmacokinetics: Absorption: When giving the drug 900, 1,200, 2,400, 3,600 and 4,800 mg per day (3 times per day), the bioavailability appears as 60%, 47%, 34%, 33% and 27% respectively. Food slightly effects on amount and rate of drug absorption by increasing 14% of AUC and C_max.
Distribution: Less than 3% of gabapentin circulate in blood as plasma protein binding. In patients with epilepsy, Gabapentin concentrations in cerebrospinal fluid (CSF) are approximately 20% of corresponding steady state through plasma concentrations.
Excretion: Gabapentin is eliminated by renal excretion as unchanged drug.