XV Multiple Oral Dose Administration

Objectives:

==> To recognize and use the integrated equations used to describe plasma concentrations versus time after multiple oral doses

==> To calculate appropriate multiple dose drug regimen

==> To define, use, and calculate the parameter

So far we have looked at multiple IV bolus administration. In an analogous fashion, equations can be developed which enable you to calculate the plasma concentration achieved following multiple oral administration. To start the plasma concentration achieved following a single oral dose can be given by:-

Equation XV-1 Cp after a Single Oral Dose

This can be converted to an equation describing plasma concentration at any time following n equal doses with constant dosing interval t.

Equation XV-2, General Equation

Figure XV-1, Plot of Cp Versus Time for Multiple Oral Doses showing Cp_max and Cp_min

Using a JAVA aware browser you can create your own version of Figure XV-1.

Plasma Concentration versus Time Plots

The plasma concentration versus time curve described by this equation is similar to the IV curve in that there is accumulation of the drug in the body to some plateau level and the plasma concentrations fluctuate between a minimum and a maximum value.

The Cpmax value can be calculated at the time t = t_peak after many doses (n -> ) but it is complicated by the need to determine the value for t_peak.

This page was last modified: 7 August 2003