Introduction To Pharmacokinetics

Oral Dosing - Introduction

A patient is given a 500 mg dose of a drug via a single oral dose and the concentration- time data is collected.

When the concentration-time data is plotted, you see the semilogarithmic graph across. You will use this graph to calculate pharmacokinetic parameters.


The following is already known about the drug:
Bioavailability (F) = 0.45

The first pharmacokinetic parameter you will find is the elimination half-life (t1/2).

Once you know the elimination half-life, you can then go on to calculate the elimination rate constant (k).

Have a look at the concentration-time data and then turn to the next page.

Time (h) Plasma Drug Concentration (mg/L)
00
0.52.5
13.2
1.53.1
22.8
32.0
41.3
50.8
60.5
70.3
80.2