In this video we will solve 7 typical questions, related to the volume of distribution calculation. Questions & timecode navigation are below. Enjoy!

00:00 - JAP is a 67-year-old male and retired metalworker, was admitted to the hospital due to decompensated heart failure. The patient present with a history of progressive dyspnea, triggered by less than ordinary activities, lower-extremity edema, and abdominal enlargement. He is started on digoxin for his congestive heart failure (CHF). The initial dose was 0.3 mg. The C0, obtained by extrapolation of the elimination phase, is determined to be 0.15 mg/L.
Based on provided above data, what is the patient's apparent volume of distribution?
A. 0.5 L
B. 0.045 L
C. 0.25 L
D. 2 L
E. 4 L
F. 6 L

01:10 - A 42-year-old male patient with body weight 70 kg was diagnosed with severe infection involving Pseudomonas aeruginosa and MRSA (Methicillin-resistant S. aureus). He received 2000 mg of appropriate antibacterial agent as a continuous IV infusion (loading dose). The peak plasma concentration of administered antibiotic was measured as 28.5 mg/L.
Which of the following is the apparent volume of distribution of antimicrobial agent:A. 1 L/kg.
B. 2 L/kg.
C. 0.013 L/kg.
D. 43 200L/kg.
E. 1824 L/kg.
F. 75 L/kg.

03:44 - Ms. James, a 68-year-old woman with right-side lobular pneumonia, was given an antibacterial agent vancomycin, 150 mg, via intravenous infusion. After 20 minutes of infusion, the plasma concentration was measured and was found to be 3 mg/L.
Assuming that there were no elimination of the antibacterial agent in 20 minutes, what is the apparent volume of distribution of vancomycin?
A. 3 L/min
B. 3 L
C. 50 L
D. 7 L
E. 0.1 mg/min
F. 25 L

04:46 - The graph shows some data concerning a new drug F. We administering an IV dose (5 mg/kg) of the drug to a 70-kg patient. After allowing time for redistribution and equilibration of the drug in various body compartments, we measure plasma concentrations at various times.
Which value comes closest to the apparent Vd for this drug?
A. 0.62 L
B. 19 L
C. 50 L
D. 110 L
E. 350 L

09:24 - A 10-mg dose of a newly developed medication that follows first-order elimination kinetics was injected via IV route to healthy subjects during phase I clinical trial. The volume of distribution (Vd) of the drug turned out to be 80 L.
Which of the following would have been the volume of distribution of the drug (in liters) if the administered dose were 20 mg?
A. 100 L
B. 50 L
C. 80 L
D. 200 L
E. 160 L

11:24 - A one investigational study is conducted to assess pharmacokinetic parameters of a new antimicrobial medication in normal individuals. The clearance and half-life of the new drug are determined to be 7.0 L/hour and 10 hours, respectively.
Which of the following is the best estimate of the volume of distribution for this drug?
A. 1.5 L
B. 4.9 L
C. 18 L
D. 49 L
E. 100 L
F. 350 L

13:17 - A new medication is under study in phase 1 clinical trials. It is found that this molecule is avidly taken up by extravascular tissues & interstitial fluid so that the final total amount in the extravascular compartment at steady state level is 100 times greater the amount remaining in the blood plasma.
Assuming if patient has 8 L of blood and 4 L of plasma, what is the probable volume of distribution in this individual?
A. Insufficient data to calculate
B. 8 L
C. 14.14 L
D. 100 L
E. 404 L

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