Pharmacokinetic effects of vigabatrin on cerebrospinal fluid amino acids in humans.

A study was conducted to assess the impact of single dosing and different dosing intervals of vigabatrin [gamma vinyl GABA (GVG)] in 11 patients with drug-resistant complex partial seizures. Cerebrospinal fluid (CSF) concentrations of total GABA, free GABA, homocarnosine, homovanillic acid (HVA), GVG, and 5-hydroxyindolacetic acid were measured up to seven days after a single dose. GVG levels were maximal within 24 h, suggesting that GVG acts to inhibit GABA-transaminase, and may also increase biogenic amines.