The effect of thiopentone on the CNS is quickly terminated because of:

Thiopentone is a ultra sho acting barbiturates ,its action is terminated because of redistribution . thiopentone is highly lipid soluble ,after i.v injection consciousness is regained in 6-10 minutes due to redistribution ,while the ultimate disposal occurs by metabolism. Greater the lipid solubility of the drug ,faster is its redistribution. Ref: KD Tripathi 8th ed