Gabatin Mechanism of Action

Antiepileptic.
Pharmacology: Pharmacodynamics: Gabapentin is structurally related to the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). It has sufficient lipid solubility to cross the blood-brain barrier. Despite its structural relationship to GABA and demonstrate antiepileptic activity, gabapentin's precise mechanism of action remains unknown. It does not modify GABA_A or GABA_B. It is not converted metabolically into GABA or a GABA agonist, and it is not an inhibitor of GABA uptake or degradation.
Gabapentin also has no affinity for binding sites on common neuroreceptors such as benzodiazepine, glutamate, N-methyl-D-aspartate (NMDA), quisqualate, kainite, strychnine-insensitive or strychnine-sensitive glycine, alpha1, alpha2, or beta adrenergic, adenoside A1 or A2, cholinergic muscarinic or nicotinic, dopamine D1 or D2, histamine H1, serotonin S1 or S2, delta, or kappa, cannabinoid 1, voltage-sensitive calcium channel sites labeled with nitrendipine or diltiazem, or at voltage-sensitive sodium channel sites labeled with batrachotoxinin A20-alpha-benzoate. Furthermore, gabapentin does not alter the cellular uptake of dopamine, noradrenaline or serotonin. The mechanism of gabapentin's anticonvulsant action is unknown. Gabapentin exhibits antiseizure activity in mice and rats in both the maximal electroshock and pentylenentetrazole seizure models and other preclinical models (e.g., strains with genetic epilepsy, etc.). The mechanism of gabapentin's analgesic action is unknown. In animal models, gabapentin prevents allodynia (pain-related behavior in response to a normally innocuous stimulus) and hyperalgesia (exaggerated response to painful stimuli). It prevents pain-related responses in neuropathic pain models and decreases pain-related responses after peripheral inflammation in rats or mice.
Pharmacokinetics: Gabapentin is absorbed from the gastrointestinal tract by means of a saturable mechanism. Following multiple dosing peak plasma concentrations are usually achieved within 2 to 3 hours of administration and steady state achieved within 1 to 2 days. Gabapentin is not appreciably metabolized and most of a dose is excreted unchanged in the urine with the remainder appearing in faeces. Gabapentin is widely distributed throughout the body but binding to plasma proteins is minimal. The elimination half-life has been reported to be about 5 to 7 hours. Gabapentin is distributed into breast milk.