Dose size and dosing interval determination.

Knowing the necessary minimum inhibitory or minimum effective concentration of a drug dose size and/or dosing interval for multiple dose therapy can be calculated under the assumption that the blood level-time curve of a drug can be described by an open one-compartment or an open two-compartment model, that the drug does not show dose dependent pharmacokinetics for the therapeutic dose range and that the distribution coefficient is applicable for a wide body weight range and age group, excluding severe edemas and obesity. The dose size and dosing interval equations are derived from the minimum blood-level concentration c'min equation in multiple dosing. Substituting c'min by MIC or MEC, cop by D - f/Vd and Vd by delta' - BW either the required dose size or dosing interval can be calculated. In the case of renal failure adjustment can be made by inclusion of a correction factor into the equations using either the observed creatinine clearance or the serum creatinine value.