Clinical pharmacokinetics worksheet with answers

Practice exercise (made-up values, not clinical guidance). A patient who weighs 50 kg needs a loading dose of tobramycin to reach a level of 10 mg/L straight away. The volume of distribution is 0.3 L/kg. Find the loading dose LD in mg.

Practice exercise (made-up values, not clinical guidance). A patient starts regular doses of digoxin, which has a half-life of 48 h. Using the rule that steady state is reached after about five half-lives, after how many hours t_ss is steady state reached?

Practice exercise (made-up values, not clinical guidance). A 73 kg patient is to receive an aminophylline infusion (salt factor S = 0.8: 80% of aminophylline is theophylline). The theophylline clearance is 0.03 L/kg/h. What aminophylline infusion rate R in mg/h gives a steady-state theophylline level of 12 mg/L?

Practice exercise (made-up values, not clinical guidance). A patient receives an IV bolus of 260 mg of tobramycin. The level back-extrapolated to time zero is 9 mg/L and the half-life is 2.5 h. Find the volume of distribution Vd.

Practice exercise (made-up values, not clinical guidance). A patient receives vancomycin IV every 12 h; the vancomycin clearance is 5 L/h. Each dose is 1000 mg of vancomycin. Find the average steady-state level C_ss,avg.

Practice exercise (made-up values, not clinical guidance). An 88 kg patient takes oral theophylline (F = 1) every 8 h. The clearance is 0.05 L/kg/h. Each dose is 200 mg of theophylline. Find the average steady-state level C_ss,avg.