An i.v. bolus dose of thiopentone leads to loss of consciousness within 10–15 sec. The patient regains consciousness in just a few minutes. This is because it is:: (A) Renally excreted, (B) Exhaled rapidly, (C) Rapidly metabolised by hepatic enzymes, (D) Redistributed from brain to other body tissues
Answer is D. Thiopentone and other highly lipid soluble agents first reach the highly perfused organs like the brain. Therefore, the onset of ac­tion of these agents is very quick. However, action also terminates quickly because of redistribution to less well-perfused tissues like fat and muscle.