One way to achieve a therapeutic concentration more quickly is to give a loading dose by rapid intravenous injection and then start the slower maintenance infusion.
- : For Drugs which can be given as a bolus :-
For example, theophylline again.
To achieve Cpss = 14.1 mg/L; k0 = 60 mg/hr; V = 25 L; kel = 0.17 hr- 1.
A loading dose can be calculated from
DOSE = V * Cp0 = 25 x 14.1 = 353 mg
Figure VI-3. Linear Plot of Cp versus Time Showing Bolus, Infusion, and Combined Curves
The plasma concentration time curve is as shown in Figure VI-3:-
Plasma Concentration versus Time Plots
Calculate Cp given k0, Bolus Dose, kel and V at time t
Copyright 2001 David W.A. Bourne