| Abstract: | One of the most successful approaches to adjustment of dosage regimens on the basis of single determinations of drug contents in blood specimens provides the blood sampling at the "ideal" moment (t*), i. e. at the time equal to the inverse value of the elimination rate constant. The above version of the one-point method is applicable to drugs obeying the one-compartment model. In practice, however, it is never known a priori whether the individual pharmacokinetic profile (PKP) is monoexponential or not. An attempt was made to apply the one-point method to individual amikacin (Am) intravenous bolus dosing in 27 patients with PKPs described not only by mono- but also by biexponential equations. The individual doses (Dc) estimated on the basis of Am concentrations recorded at the "ideal", point (2.75 hours after the administration) by the equation Dc = Dp.Cp(t*)/Ci(t*) were compared to the doses (DCl) found on the basis of greater than or equal to 4 determinations of the Am concentration (within 0.5 to 6 hours after the administration), i. e. by the equation DCl = Dp.Cli/Clp, where: Dp is the population value of an Am dose (7.5 mg/kg); Cp (t*) is the population value of an Am concentration at t* (6.7 mg/l), Clp is that of the total clearance [81.2 ml/(h.kg)] and Ci (t*) and Cli are the individual values of an Am concentration and clearance, respectively. The correlation coefficient of the DCl vs. Dc estimates was equal to 0.87. In 17 patients with monoexponential PKPs it was higher (r = 0.99).(ABSTRACT TRUNCATED AT 250 WORDS) |
