<prompt> Action of i. v. thiopentone is terminated by -Rapidly renal excretionOxidationRedistributionConjugation  <response>: Ans. is c i.e., Redistribution Ref: K D Tripathi 7the p. 400o Three proceeses are involved in the termination of action of barbiturates: the relative importance of each varies with the compound.i Redistribution: it is important in the case of highly lipid soluble thiopentone. After iv injection the action of thiopentone is terminated in 6-10 mins by redistribution while the ultimate disposal occurs by metabolism tl 2 of elimination is 9 hours.Metabolism: drugs with intermediate lipid solubility short acting barbiturates are primarily metabolized in liver by oxidation, dealkylation and conjugation. Their plasma tl2 ranges from 12-40 hours.Excretion: barbiturates with low lipid solubility long acting agents are significantly excreted unchanged in urine. The tl2 of phenobarbitone is 80-120 hours. Alkalinization of urine increases ionization and excretion.Long acting barbituratesShort acting barbituratesUltrashort acting---Phenobarbitone, Mephobarbitone.Butobarbitone, secobarbitone, Pentobarbitone.Thiopentone, Methohexitone, Hexobarbitone. 