Pharmacology

Question 1

What is tachyphylaxis?

Answer 1

Rapidly decreasing response to a drug after administration of only a few doses

Question 2

Most drugs are characterized by:

Answer 2

Molecular weight (MW) of 350 or less,
ensuring movement of unbound drug between endothelial cells despite the presence of protein filters in the endothelial gaps. (Except BBB)

Question 3

Most drugs in the body move by:

Answer 3

Passive diffusion

Question 4

What is partition coefficient?

Answer 4

Experimental measure of relative lipid solubility as influenced by the chemical structure of the drug.

Question 5

Drug pKa

Answer 5

the pH at which the drug is 50% ionized and 50% nonionized; ratio 1:1

Question 6

Diseases associated with fluid retention or obesity are likely to (increase/decrease) the Vd of many drugs, and thus (increase/decrease)x plasma drug concentration.

Answer 6

Increase

Decrease

Question 7

In general terms, what is phase I metabolism?

Answer 7

Phase I metabolism chemically changes the drug so that it is more water soluble and thus more susceptible to phase II metabolism

Question 8

In general terms, what is phase II metabolism?

Answer 8

Phase II metabolism generally renders the drug sufficiently water soluble to be renally excreted

Question 9

Phase I reactions include:

Answer 9

Oxidation
Hydrolysis
Reduction

Question 10

What is another name for phase II metabolism?

Answer 10

Conjugation

Question 11

What is the mechanism of action of doxycycline?

Answer 11

Binds to the 30S ribosomal unit during protein synthesis - Bacteriostatic

Question 12

What is the mechanism of action of cisapride?

Answer 12

5HT-4 agonist

Question 13

What is the MOA of ondansetron?

Answer 13

5HT-3 antagonist (central and peripheral actions)

Question 14

What is the MOA of gabapentin?

Answer 14

Inhibits voltage-gated Ca++ channels

Question 15

What is the MOA of cyclosporin? What does it decrease?

Answer 15

Inhibits calcineurin:

-Decreases IL-2 production

Question 16

What is the mechanism of action of enrofloxacin?

Answer 16

DNA girase inhibitor

Question 17

What is the mechanism of action of slentrol?

Answer 17

Weight loss drug - Microsomal triglyceride transfer protein (MTTP or MTP) inhibitor.

Works on enterocytes to prevent transfer of lipids into bloodstream

Question 18

What is the location of nephrotoxicity of gentamicin?

Answer 18

Proximal tubule

Question 19

What is the mechanism of action of aspirin?

Answer 19

Irreversible cox inhibition

Question 20

What drugs decrease CSF production?

Answer 20

Omeprazole, pred, mannitol, acetazolamide

Question 21

What is a side-effect of misoprostol?

Answer 21

Abortion in people

Question 22

What antibiotics penetrate the prostate?

Answer 22

TMS, chloramphenicol, enrofloxacin

Question 23

What drug can result in hypothyroidism?

Answer 23

TMS

Question 24

What are the interactions between enrofloxacin and theophylline?

Answer 24

In dogs, enrofloxacin leads to higher theophylline concentrations by about 30-50%

So if you give together - need to decrease dose of theophylline

Question 25

If you give theophylline and enrofloxacin together, which drug do you need to dose-reduce?

Answer 25

Theophylline

Question 26

MOA of mirtazapine

Answer 26

a-2 antagonist

Also inhibits 5-HT2, 5-HT-3, and H1 receptors.

Question 27

What is the MOA of maropitant (Cerenia)

Answer 27

NK-1 antagonist

Question 28

What is Cmax?

Answer 28

Cmax is the highest (peak) plasma drug concentration that is reached after a given dose.

Question 29

What is Tmax?

Answer 29

Tmax is the time at which the peak plasma drug concentrations are reached