3 Medical Mathematics: Absorption of Drugs Flashcards Preview

Vet Prep > 3 Medical Mathematics: Absorption of Drugs > Flashcards

Flashcards in 3 Medical Mathematics: Absorption of Drugs Deck (13):
0

What is Absorption of drugs?

Is the transfer of the drug from the site of administration to the circulation

1

What are the factors that affect drug absorption?

Factors related to the drug
Factors related to the animal

2

What are the factors that are related to the drug?

molecular size
lipid solubility
degree of ionization
dissolution drug in water
concentration of drug at absorptive site
route of administration

3

Molecular size

The smaller the molecular size, the faster is penetration through the pores

4

Lipid solubility

The greater the lipid solubility, the greater is diffusion

5

Degree of ionization

The higher the ratio between N/I, the faster is diffusion

6

Dissolution of drug in water

Oral absorption of liquid drugs is faster than solid drugs.
Oral absorption of solid drugs depends on their rate of dissolution

7

Concentration of drug at absorptive site

Depends on the dose and concentration.
The higher the concentration the faster is absorption

8

List the Routes of administration of drugs

Sublingual and inhalation have a very rapid absorption.
Intramuscular is slower than sulingual and inhalation.
Subcutaneous is slower than intramuscular.
Oral is usually slower than injection

9

What are the factors related to the animal?

Blood flow
Absorbing surface area
Connective tissue
Species
Individual

10

Blood flow

Absorption of a drug from a particular site is related to blood flow to that site.
Increased blood flow increases drug absorption.
Drugs, physiological factors and disease can modify blood flow.
Heat or massage of intramuscular injection site increases blood flow and absorption.
Sympathetic stimulation increases blood flow to skeletal muscles.
Sympathetic stimulation decreases blood flow to the GI tract and subcutaneous sites
and skin.
Shock and edema decrease blood flow

11

Absorption from the GI tract

The upper part of the small intestine is the main site of absorption for all drugs given orally because of the extensive surface area and rich blood supply.
Therefore, the rate of absorption depends on the rate of gastric emptying.
Drugs and disease can modify the rate of gastric emptying.

12

What factors affect drug absorption from the GI tract?

The rate of absorption of solid drugs depends on their rate of dissolution.
Activity of the gut.
Presence of other substances.
Blood flow.
Species.
Individual.

Decks in Vet Prep Class (47):