Multiple drug administration

Steady state concentration

The steady state concentration is directly proportional to the administered dose if the total body clearance remains constant.

Time to achieve steady state

It takes 5 - 6 elimination half lives to achieve steady state.

Half Life (hr)
S.S.
S.S.
S.S.

Loading dose

Administration of a loading dose leads to faster approach to steady state without affecting the steady state plasma concentration. The steady state conc depends only on the drug administration rate and the drug total body clearance.

Loading dose (mg)
Steady state