Clinical pharmacokinetics worksheet with answers

Practice exercise (made-up values, not clinical guidance). The elimination rate constant of vancomycin in a patient is 0.0866 h⁻¹. Find the half-life t½.

Practice exercise (made-up values, not clinical guidance). A patient receives aminophylline as a constant IV infusion without a loading dose. The half-life is 8 h. What percentage f of the steady-state level has been reached after 8 h?

Practice exercise (made-up values, not clinical guidance). Vancomycin is given as a continuous infusion to a patient whose vancomycin clearance is 5 L/h. What infusion rate R in mg/h gives a steady-state level of 25 mg/L?

Practice exercise (made-up values, not clinical guidance). A patient receives an IV bolus of 190 mg of gentamicin. The level back-extrapolated to time zero is 8 mg/L and the half-life is 2.5 h. Find the clearance CL in L/h.

Practice exercise (made-up values, not clinical guidance). An 82 kg patient has a theophylline level of 6 mg/L; the target is 15 mg/L. The drug is given intravenously as aminophylline (S = 0.8), and the volume of distribution is 0.5 L/kg. What extra loading dose LD raises the level to the target?

Practice exercise (made-up values, not clinical guidance). A 67 kg patient takes oral theophylline (F = 1) every 12 h. The clearance is 0.05 L/kg/h. Each dose is 500 mg of theophylline. Find the average steady-state level C_ss,avg.