The relative potencies of thiopentone and propofol

The relative potencies of the intravenous anaesthetics propofol and thiopentone have been investigated by finding the dose necessary to produce unconsciousness in approximately 30%, 50% and 80% of patients. The estimated potency of propofol to thiopentone was 1:1.604 as obtained by the probit method of analysis which estimates the logarithm of the relative potency.