Vigabatrin

pharmacological · nervous · Oral

Vigabatrin. Irreversible GABA-aminotransferase (GABA-T) inhibitor — raises CNS GABA. Approved for refractory complex partial seizures +… Oral half-life 6.8 h.

Irreversible GABA-aminotransferase (GABA-T) inhibitor — raises CNS GABA. Approved for refractory complex partial seizures + infantile spasms. Permanent visual field constriction in ~30% mandates ophthalmologic monitoring → REMS program.

PK: half-life corrected 7 -> 6.8 h, the figure its own paper states. F 0.92 was a RELATIVE bioavailability, fed against fasted, not an absolute one, and is dropped; no absolute figure exists in any abstract. V 56 L is retained but re-attributed to PMID:1395360 as 0.8 L/kg and is APPARENT, so F is pinned to 1 rather than paired with a separate bioavailability. ka 1.2 /h dropped. THE PLASMA BLOCK IS DISPOSITION ONLY: vigabatrin inactivates GABA transaminase irreversibly, so its effect outlasts its curve by days and duration is set by enzyme resynthesis.

Pharmacokinetics

• Oral — t½ 6.8 h · F 100% · Vd 56 L

Sources: PMID:2757905, PMID:1395360