Description
Winurina (Gabapentin) is used with other medications to treat partial seizures and it can be used to relieve to burning nerve pain that sometimes persists for months or even years after an attack of shingles (herpes zoster).
Composition
Winurina 100 mg Capsules contain Gabapentin USP …… 100 mg
Winurina 300 mg Capsules contain Gabapentin USP……… 300 mg
Mechanism of Action
Winurina (Gabapentin) is structurally related to the neurotransmitter GABA (gamma - aminobutyric acid). Exact mechanism of its CNS depressant and anticonvulsant activity is not fully understood. In vitro studies with radio-labeled Gabapentin have revealed a Gabapentin site in areas of rat brain including neocortex & hippocampus
Pharmacokinetics and Metabolism
All pharmacological actions following Gabapentin administration are due to the activity of the parent compound; Gabapentin is not appreciably metabolized in-humans.
Oral Bio-availability
Gabapentin bioavailability is not dose proportional; i.e., as dose is increased, bioavailability decreases. Bioavailability of Gabapentin is approximately 60%, 47%, 34%, 33%, and 27% following 900, 1200, 2400, 3600, and 4800 mg / day given in 3 divided doses, respectively. Food has only a slight effect on the rate and extent of absorption of Gabapentin.
Distribution
Less than 3% of Gabapentin is bound to plasma protein
Elimination
Gabapentin is eliminated from the systemic circulation by renal excretion as unchanged drug. Its elimination half-life is 5 to 7 hours and is not altered by dose or following multiple dosing. In elderly patients, and in patients with impaired renal function, Gabapentin plasma clearance is reduced.
