Drug Metabolism Quiz Flashcards
Consider a medication that is eliminated by the cYP 450 microsomal enzyme system. Replace xxx and yyy with the word enhances or the word reduces for your answer.
A CYP 450 inhibitor xxx the activity of drugs that are substrates. A CYP 450 inducer yyy the activity of drugs that are substrates.
xxx = enhances
yyy = reduces
Which opioid does not have to go through the CYP 450 enzyme system?
Codeine
Fentanyl
Methadone
Morphine
Morphine
Identify the incorrect answer:
a) Hydrophilic medications are cleared by the kidney.
b) Hydrophobic medications are cleared by hepatic and extra hepatic microsomal enzymes.
c) The hepatic and extra hepatic microsomal enzymes are responsible for Phase I, or complex, metabolism.
d) Since phenobarbital has a very lengthy half life we know that it must be directly eliminated by the kidney.
d) Would be correct if it said eliminated by the liver/extra hepatic/complex metabolism
Which response is correct:
a) Oxidation refers to the insertion of one atom of oxygen into an organic substrate while the other oxygen atom is reduced to water
b) Oxidation tends to make a compound less water soluble and hence prevent excretion by the kidney
c) The microsomal enzyme system acts on medications that cost more than 450 pounds per dose
d) Hepatic clearance ALWAYS results in an inactive compound
a
T or F: Oseltamivir, a neuraminidase inhibitor, is most effective when administered within 48 hours of influenza symptoms
True
In this example for medication X a dose of 1200 mg was taken at 9 AM this morning. Assume that all of the drug was completely absorbed. The half life of this drug is 12 hours. The drug is taken once a day and the next dose will be taken at 9 AM tomorrow. What dose should be taken on the second day so that the amount in the body after oral absorption is 1200 mg?
900 mg
Consider the Histamine type 1 antagonists discussed in class (diphenhydramine, hydroxyzine, cetirizine). The most potent and most selective of these three is ___________.
Cetirizine
