Page 66 - Interactive Theoritical Notes of Bioharmaceutics and pharamcokinetics.docx compressed

PharmD clinical pharmacy program Level 3, Semester 2 Biopharmaceutics & Pharmacokinetics (PT608(

True steady-state plasma concentration (Css)

 Before reaching a true steady-state condition, the rate of infusion is always greater

than the rate of elimination (i.e. R >> KDB)

 During constant rate IV administration, the drug accumulates until steady state is

achieved after 5 t½.

 At true steady state, the rate of drug entering the body (infusion rate) is equal to the

rate of drug leaving the body (elimination rate) and, theoretically, it occurs only when

t=  .

 The loading dose is an IV bolus dose administered at the time of starting the IV

infusion to achieve faster approach to steady state.

 The plasma concentration that corresponds to true steady state is referred to as the true

steady state plasma concentration (C ss).

 The Css of a drug is constant for a given infusion rate and is obtained as time

approaches infinity (t= ).

65