Pharmacokinetics Basics: Half-Life, Clearance & Steady State

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Model the plasma concentration of placeholder Drug K after an IV bolus over 24 hours, the share that remains, the time to fall to a reference level, and chart the decay curve.
• Estimate the elimination rate constant, the half-life and the back-extrapolated starting concentration of Drug K for six subjects from two blood samples each.
• Calculate the apparent volume of distribution of Drug K for five subjects, scale it per kilogram and apply the loading-dose formula with bioavailability as a calculation exercise.
• Calculate the area under the concentration-time curve of Drug K with the trapezoid rule, add the extrapolated tail and derive the clearance, then compare it with k × Vd.
• Follow peaks and troughs of Drug K over ten repeated IV doses, compare them with the steady-state formula and chart the build-up to the plateau.
• Compare five placeholder drugs: elimination rate constant, accumulation ratio for their dosing interval and the time to reach 95% of steady state.
• Calculate the steady-state concentration of a constant-rate Drug K infusion, its elimination rate constant, the concentration over 48 hours and the time to reach 90% of the plateau.
• Estimate how reduced kidney function lowers the total clearance and lengthens the half-life of Drug K for six practice patients, and flag the cases that need review.