1. A drug was present in the plasma shortly after IV administration at a concentration of 300 µg/ml. Eight hours later, the plasma concentration was determined at 75 µg/ml. Assuming first order kinetics, the half-life of the drug is approximately:
    1. 30 minutes
    2. 60 minutes
    3. 2 hours
    4. 4 hours
    5. 6 hours
  2. A drug is administered intravenously in a dose of 200 mg to an 80 kg male patient. After 4 hours the plasma concentration was 1.5 mg/ml. Assume that the apparent volume of distribution is 10% of body weight. The total amount of drug in body fluids at 4 hours is approximately:
    1. 15 mg
    2. 30 mg
    3. 60 mg
    4. 90 mg
    5. 120 mg
  3. A single dose of a drug is given to an 85 kg female patient. The drug is known to have an apparent volume of distribution of 20% of body weight and elimination half-life of 2 hours. The total body clearance of this drug is:
    1. 20 ml/min
    2. 50 ml/min
    3. 100 ml/min
    4. 170 ml/min
    5. 340 ml/min
  4. Drug X is administered via constant infusion at a rate of 150 µg/min. The half life of drug X is 15 hours, the elimination constant (ke) is 0.046/hr, the volume of distribution is 40 L. What is the steady state concentration?
    1. 0.082 µg/ml
    2. 4.89 µg/ml
    3. 4.89 mg/ml
    4. 9.8 µg/ml
    5. 0.0489
  5. In order to attain a steady-state concentration of 25 µg/ml, at what infusion rate must drug X be administered via constant infusion if the half-life of drug X is 15 hours, the elimination constant (ke) is 0.046/hr, and the volume of distribution is 40 L?
    1. 25 µg/min
    2. 300 µg/min
    3. 600 µg/min
    4. 760 µg/min
    5. 0.019 µg/min
  6. Use the graph below to calculate some key pharmacokinetic parameters. The dose is 200 mg. Calculate Ke, Clp, T1/2 , and Vd. State if drug Q is bound to plasma proteins.
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