Clinical pharmacokinetics worksheet with answers

Practice exercise (made-up values, not clinical guidance). In a patient, lidocaine has an elimination half-life of 2 h. Find the elimination rate constant k in h⁻¹.

Practice exercise (made-up values, not clinical guidance). A patient starts regular doses of gentamicin, which has a half-life of 3 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). After an IV dose of gentamicin, the level is 10 mg/L at 1 h and 5 mg/L at 3 h. Assume first-order elimination. Find the half-life t½.

Practice exercise (made-up values, not clinical guidance). After an IV dose of tobramycin, the level is 10 mg/L at 1 h and 3.1 mg/L at 6 h. Assume first-order elimination. Find the half-life t½.

Practice exercise (made-up values, not clinical guidance). A vancomycin infusion is started without a loading dose. The half-life in this patient is 6 h. How long t does it take to reach 95% of the steady-state level?

Practice exercise (made-up values, not clinical guidance). A 59 kg patient on regular gentamicin doses is at steady state. The target is a peak of 10 mg/L and a trough of 1 mg/L, and the volume of distribution is 0.3 L/kg. Assuming rapid IV doses, what dose D raises the level from the trough to the peak?