Changing the dosing interval and the dose in the same proportion should produce the same Cpaverage concentration. However, the Cpmin and Cpmax can vary considerably.
With F = 1.0, V = 30 liter, t1/2 = 6 hours or kel = 0.693/6 = 0.116 hr-1, a dose of 600 mg given every 12 hours will achieve an average plasma concentration of approximately 15 mg/L. Try simulating this regimen and also the alternate regimen of 1200 mg very 24 hours and 300 mg every 6 hours. Which regimen gives the least variation between Cpmax and Cpmin?
iBook and pdf versions of this material and other PK material is available
Copyright © 2001-2022 David W. A. Bourne (david@boomer.org)