Using pharmacokinetics in drug therapy II: Rapid estimates of dosage regimens and blood levels without knowledge of pharmacokinetic variables.

A modification of the superposition method, which yields fast and reasonably accurate estimates of dosage regimens and steady-state maximum and minimum blood levels, is described. In the modified superposition method, input data are obtained from the blood, plasma or serum concentration vs time profile resulting from administration of a single dose of the drug. These estimates are valid only when the pharmacokinetics of the drugs are linear and elimination from the body occurs according to first-order kinetics. Limitations of the method are discussed. It is concluded that this is a rapid and clinically useful method for pharmacokinetic estimations.