Pharmacokinetics

Question 1

Enteric drugs

Answer 1

administered through the GI tract

Question 2

4 types of enteric drugs

Answer 2

oral, sublingual, buccal and rectal

Question 3

What is an advantage of IV meds?

Answer 3

they circulate fast

100% bioavailability

Question 4

What is an advantage of oral meds?

Answer 4

very safe

cheap

Question 5

Bioavailability

Answer 5

the amount of drug that reaches systemic circulation

Question 6

First pass metabolism

Answer 6

lowers bioavailability of drug

Question 7

4 ways a drug can cross membranes and get into blood

Answer 7

1) Endocytosis
2) Passive diffusion
3) Active transport
4) Pore transport

Question 8

Indirect active transport

Answer 8

antiport and synport

*still requires ATP to move against gradient, just going with or against another molecule

Question 9

main pathway for drug transport

Answer 9

passive diffusion

Question 10

facilitated diffusion

Answer 10

use ATP to directly move substance across membrane

Question 11

What form must drugs be in to work?

Answer 11

non-ionized

Question 12

What happens when pH = pKa

Answer 12

~50% of drugs are in non-ionized form

Question 13

How can you get drugs to be closer to non-ionized form?

Answer 13

put in pH that is similar to their pKa or more extreme

ex: acids will be less ionized in an acidic environment

Question 14

When will bases be less ionized?

Answer 14

in a basic environment

Question 15

What is the pH of the stomach?

Answer 15

3.4

Question 16

When would you want low bioavailability?

Answer 16

if you want an oral drug to target the gut

drug doesn’t need to go to bloodstream

Question 17

Distribution of drugs

Answer 17

determines where they act, where they are eliminated and how long they last in the body

Question 18

What does small Vd mean?

Answer 18

drug stays in plasma

Question 19

Vd < 14 L

Answer 19

you are in plasma

Question 20

Vd 14-49 L

Answer 20

you are in extracellular tissue

Question 21

Vd > 50 L

Answer 21

you are in fat

Question 22

ion trapping

Answer 22

if you place a drug with a certain pKa in an environment where the pH is very different, the drug will become ionized

this can trap the ionized drug in certain environments

Question 23

What happens is all albumin sites are saturated in blood?

Answer 23

the drug will leave the blood and enter the plasma

serum level of drug drops and tissue level rises