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:
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.
Renally excreted
Exhaled rapidly
Rapidly metabolised by hepatic enzymes
Redistributed from brain to other body tissues