Barriers To Drug Absorption

Question 1

For absorption drug has to….

Answer 1

Question 2

What are the 4 barriers to drug absorption

Answer 2

Lumen
Unstirred water layer
Gastrointestinal membrane transcellular
Pre systemic metabolism

Question 3

The environment of the lumen that affects the absorption includes what

Answer 3

Gastrointestinal pH
Luminal enzymes
Food
Disease state and physiological disorders

Question 4

Explain the gastrointestinal pH in the lumen

Answer 4

Question 5

Explain the mechanism of how pH affects drug absorption

Answer 5

Question 6

Explain the luminal enzymes

Answer 6

Question 7

How do luminal enzymes affect the absorption of the drug

Answer 7

Question 8

List the mechanism of how food affects drug absorption

Answer 8

Complication of drugs with components of the diet
Competition between food components and drugs for specialized absorption mechanisms
Alteration of pH
Alteration of gastric emptying
Increased viscosity of gastrointestinal contents
Food-induced changes in blood flow

Question 9

Explain Complication of drugs with components of the diet as one of the mechanisms of how food affects drug absorption

Answer 9

Question 10

Explain competition between food components and drugs for specialized absorption as one of the mechanisms of how food affects drug absorption

Answer 10

Question 11

Explain alteration of pH as one of the mechanisms of how food affects drug absorption

Answer 11

Question 12

Explain alteration of gastric emptying as one of the mechanisms of how food affects drug absorption

Answer 12

Question 13

Explain increased viscosity of gastrointestinal contents as one of the mechanisms of how food affects drug absorption

Answer 13

Question 14

Explain food induced changes in blood flow as one of the mechanisms of how food affects drug absorption

Answer 14

Question 15

List the disease states and physiological disorders that affect the drug absorption

Answer 15

Local diseases
Gastric surgery
Gastrectomy
AIDS

Question 16

Explain how local diseases can affect drug absorption

Answer 16

Question 17

Explain how gastric surgery affects drug absorption

Answer 17

Question 18

Explain how gastrectomy effects drug absorption

Answer 18

Question 19

Explain how AIDS affect the drug absorption

Answer 19

Question 20

What comes after the lumen barrier

Answer 20

Mucus and unstirred water layer

Question 21

What can hinder drug diffusion

Answer 21

Question 22

What is unstirred water layer composed of

Answer 22

A more or less stagnant layer of water, mucus, and glycocalyx attached to intestinal wall

Question 23

How is unstirred water layer created

Answer 23

Incomplete mixing of the luminal contents near the intestinal mucosal surface

Question 24

How does the mucus and the unstirred layer affect the drug

Answer 24

Question 25

In gastrointestinal membrane the drug is affected by what

Answer 25

Structure of the membrane
Mechanisms if transport across the membrane

Question 26

Explain pre-systemic metabolism

Answer 26

Question 27

Presystemic metabolism includes what

Answer 27

Gut wall metabolism
Hepatic metabolism

Question 28

Explain how drugs are affected by gut wall metabolism

Answer 28

Question 29

Give example of gut wall metabolism

Answer 29

Question 30

What is the final barrier of oral absorption

Answer 30

Liver

Question 31

Explain how the drugs are affected by hepatic metabolism

Answer 31

Question 32

How can the first pass metabolism be avoided

Answer 32