Pharmacrystal

www.pharmacrystalniper.blogspot.com

www.pharmacrystalniper.blogspot.com

11

Pharmacokinetic Principles: Absorption

1) Bioavailability (F) is the fraction or percentage of administered drug that reaches the
systemic circulation via a given route as compared to what route?
       a) Oral
       b) IV (intravenous)
       c) IO (intraosseous)
       d) CSF (cerebrospinal fluid)
       e) Whatever route attains the target drug concentration in plasma (CT)
2) What organ is responsible for metabolism in the “first pass effect”?
       a) Brain
       b) Heart
       c) Kidney
       d) Liver
       e) Spleen
3.1) A patient is in the hospital and is stable on digoxin 0.175 mg IV qd (daily). How
much digoxin in mg. would you need to give your patient orally, given that the
bioavailability for oral digoxin tablets is 0.7?
       a) (0.175 * 0.7) / (1.0) = 0.1225 mg
       b) (0.175 * 1) / (0.7) = 0.25 mg
       c) (0.175 + 0.7) / (1.0) = 0.875 mg
       d) (0.175 + 1) / (0.7) = 1.67 mg
       e) No change is necessary
3.2) Given a graph of plasma drug concentration versus time, what part of the graph
would be used to calculate bioavailability for a PO (oral) drug administration?
       a) Maximum concentration
       b) Steady concentration
       c) Derivative of the curve (slope)
       d) Integral of the curve (area underneath)
       e) The curve is not used to calculate bioavailability
4.1) Which of the following routes of administration has a bioavailability of about 80-
100%, is usually very slow absorbing, and has prolonged duration of action?
       a) IV (intravenous)
       b) IM (intramuscular)
       c) SQ (subcutaneous)
       d) Rectal
       e) Transdermal
4.2) Which of the following routers of administration is the most convenient, although
may have a bioavailability anywhere from 5-100%?
       a) PO (oral)
       b) IV (intravenous)
       c) IM (intramuscular)
       d) SQ (subcutaneous)
       e) Transdermal
4.3) Which of the following enteral administration routes has the largest first-pass effect?
       a) SL (sublingual)
       b) Buccal
       c) Rectal
       d) Oral
4.4) Epithelial cells are connected by ____, which are tough to cross and materials often
must pass through the cells. Endothelial cells of blood vessels are connected by ____,
which proteins cannot cross but smaller drugs (MW 200-500) can.
       a) Macular gap junctions; Tight junctions