Drug Absorption

Question 1

What is the level of concentration of a drug dependent on?

Answer 1

1 - amount of drug administered
2 - how quickly drug is absorbed
3 - how it is distributed from its site of absorption to its site of action
4 - the rate the drug is metabolised
5 - the rate the drug is excreted

Question 2

Regardless of route of administration, where do all drugs have to end up so they can be carried to their site of action?

Answer 2

The blood stream

Question 3

When referring to absorption, how are drugs categorised?

Answer 3

• Lipophilic

- Hydrophylic

Question 4

What is meant by a lipophilic drug?

Answer 4

They have an affinity for fat. Dissolve in fatty contents of stomach or absorbed through GI tract in to bloodstream. Usualy oral meds.

Question 5

What is meant by a hydrophilic drug?

Answer 5

They have an affinity for water. Dissolve in water and diffuse through fluid to get to bloodstream. Usually solutions administered s/c or i/m (goes into ECF before diffusing into bloodstream.

Question 6

How is the absorption of oral medication affected?

Answer 6

• chemical nature of drug will determine how it’s absorbed
• preparation of drug (solid or solution)
• concentration (the higher the concentration the quicker it’s absorbed)
• alteration of gut motility eg. diarrhoea = faster bowel movements
• contents of the stomach may slow rate of absorption
• Formulation (inert ingredients may help or hinder absorption)

Question 7

i/m drug absorption depends on … ?

Answer 7

1 - how often the muscle is used

2 - if you rub the injection site