Loading dose depends on (DNB June 2011)
|C||Volume of distribution|
|D||Rate of clearance|
Drugs will accumulate within the body if the drug has not been fully eliminated before the next dose.
a. Steady state concentration is thus arrived at after four half lives.
b. This is all very well if you are willing to wait 4 half lives for the drug to be fully effective, but what if you are not?
c. What you may need to do is to "load" the volume of distribution with the drug to achieve target plasma concentrations rapidly: the loading dose.
The loading dose = the volume of distribution X the desired concentration (i.e. the concentration at steady state). So, one can see that in the formula of loading dose; half life does not count.