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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
Copyright 2001 David W.A. Bourne