## Post infusion

Before moving on to discussing various routes of drug administration, we can look at
the equation for plasma concentration after an infusion is
stopped.
Remember that the equation for plasma concentration versus time during an IV
infusion is:-

(Equation VI-2 from earlier)

If the infusion is continued indefinitely then the plasma concentration
approaches a steady state plasma concentration.

(Equation VI-3 from earlier)

If however the infusion is stopped the plasma concentration can be expected to
fall.

### Scheme or diagram

**Diagram VI-2. During and After an IV Infusion - One Compartment Model**

The scheme shown to represent 'after the
infusion is stopped' is the same as that for the bolus injection.

A Hypercard^{TM} Stack for exploring IV Infusion Administration calculations is available for downloading.

**For practice** try calculating required infusion rates and parameter values. Compare your answers with the computer! These problems include bolus/infusion and fast/slow infusion regimen cacluations as well as parameters determinations from two post infusion drug concentrations.

This page was last modified: 25 May 2002
Copyright 2002 David W.A. Bourne