531 - Exam 1 Q&A’s Latest Complete
Solution
Drug - ANS ✔✔ - a substance intended for use in the diagnosis, cure, mitigation, treatment,
or prevention of disease and a substance, other than food, intended to affect the structure or
any function of the body
T/F most drugs are strong acids or strong bases - ANS ✔✔ - F - most drugs are weak acids or
weak bases
What are the four things that the body does to a drug? - ANS ✔✔ - 1. Absorbs it
2. Distributes it (think about it - most drugs don't have MOA in the stomach or GI tract, the
body distributes to where it acts)
3. Bio transforms or metabolizes it
4. Eliminates it
Cimetidine inhibits CYP40 enzyme activities that are involved in the biotransformation of
certain benzos such as diazepam (valium) what effects would co-administration of
cimetidine have on diazepam?
A. decrease the clearance of diazepam
B. increase the plasma levels of diazepam
C. increase the Ka of diazepam
D. A and B
E. A, B, and C - ANS ✔✔ - D
Valium is therefore hanging around longer
Clearance is decreased because it can't reach the enzyme that metabolizes it
There is no effect on the association constant
, Rush - Advanced Pharmacology - NSG
531 - Exam 1 Q&A’s Latest Complete
Solution
Pharmacokinetics - ANS ✔✔ - what the body does to the drug
Describe absorption - ANS ✔✔ - drugs that are given orally have to get out of the gut and into
circulation
In order to do that the drugs have to pass through cell membranes
This means there has to be some form of solubility for the drug to pass through the cell
membrane
Cell membranes are made of lipids
Therefore drugs have to have some form of lipid solubility
What are cell membranes made of? - ANS ✔✔ - phospholipid bilayer
What is the only route of drug that does not have to pass through the cell membrane? - ANS
✔✔ - IV push - because it goes directly into circulation
What are the four mechanisms of transport across the cell membrane? - ANS ✔✔ - 1. Simple
diffusion
2. channel-mediated
3. carrier-mediated
4. Active Transport
Simple diffusion - what has to be true? - ANS ✔✔ - -drug has to be lipid soluble
-there has to be a concentration gradient present
-If a drug is high in fat solubility it is not going to be very water soluble - these two properties
balance each other out
, Rush - Advanced Pharmacology - NSG
531 - Exam 1 Q&A’s Latest Complete
Solution
If a drug is high in lipid solubility and it is able to be transported by simple diffusion, what
will happen once it crosses the cell membrane? - ANS ✔✔ - it may meet an aqueous solution
and because it is not highly water soluble it will need to bind to a carrier protein to be
transported throughout the circulation
What are the channels in Channel mediated transport - ANS ✔✔ - channels are two groups
of proteins on each side that create a pore in the cell membrane
How does channel mediated transport work? - ANS ✔✔ - there are two groups of proteins
on each side that create a pore in the cell membrane
There is water within the pore/channel that the water soluble drug can go through and the
protein walls of the channel create a barrier from the lipid bilayer
How carrier does mediated transport work? - ANS ✔✔ - -there is a carrier protein embedded
in the surface of the cell membrane that fits the drug that is trying to pass
-you have to have a complementary fit between the protein and the drug
-if it fits then it binds causing a conformation change
-the orientation of the protein flips over so that the open side of the protein is now on the
opposite side and the drug is transported to the other side of the cell membrane
-again a concentration gradient is needed
Conformational change - ANS ✔✔ - a change in how something is oriented
I.e. carrier-mediated transport where the protein accepts the drug, then flips, orienting the
open side of the protein to the opposite side of the cell membrane