Abstract: Many drugs can be applied more predictably and effectively if a constant plasma concentration is rapidly achieved and maintained. With the use of the twocompartment open-system model, a practical method of double-bottle intravenousinfusion is suggested. With this method, the rate of infusion is exponential with time and eventually tends to constant. The desired concentration will be achieved, rapidly and maintained in a steady-state.This procedure was verified in 12 dogs and 8 normal male volunteers. Singlebolus doses or continuous infusions of gentamycin were administered to study the pharmacokinetic behavior of this drug in each dog or individual. This information was used to calculate the dosage regimen of the method.The advantage of this method was theoretically proved.