Clinical pharmacokinetics worksheet with answers

Practice exercise (made-up values, not clinical guidance). The elimination rate constant of digoxin in a patient is 0.0173 h⁻¹. Find the half-life t½.

Practice exercise (made-up values, not clinical guidance). In a patient, lidocaine has an elimination half-life of 1.5 h. Find the elimination rate constant k in h⁻¹.

Practice exercise (made-up values, not clinical guidance). A 67 kg patient is to be loaded intravenously with phenytoin sodium to reach a phenytoin level of 15 mg/L. The volume of distribution is 0.7 L/kg and the salt factor is S = 0.92. Find the loading dose LD of phenytoin sodium in mg.

Practice exercise (made-up values, not clinical guidance). After an IV dose of vancomycin, the level is 25 mg/L at 1 h and 8.8 mg/L at 13 h. Assume first-order elimination. Find the half-life t½.

Practice exercise (made-up values, not clinical guidance). A patient's gentamicin half-life is 3 h. The target is a peak of 6 mg/L and a trough of 0.5 mg/L. Assuming rapid IV doses and first-order elimination, what dosing interval τ lets the level fall from the peak to the trough? Round to one decimal place.

Practice exercise (made-up values, not clinical guidance). A patient's gentamicin half-life is 2.5 h. The target is a peak of 6 mg/L and a trough of 0.5 mg/L. Assuming rapid IV doses and first-order elimination, what dosing interval τ lets the level fall from the peak to the trough? Round to one decimal place.