Drug Absorption

Question 1

What are the 4 basic factors of drug pharmacokinetics

Answer 1

• Absorption
• Distribution
• Metabolism
• Elimination

Question 2

Define drug absorption

Answer 2

The process of movement of an unchanged drug from the site of administration to the systemic circulation.

Question 3

What might affect a drug crossing cell membranes?

Answer 3

• Ionisation
• Lipid Solubility
• Structure

Question 4

Factors that affect absorption from the GI tract

Answer 4

• Motility
• Food
• Illness

Question 5

Benefits of IV

Answer 5

• 100% bio-availability

- Avoids first pass metabolism

Question 6

Benefits of topical

Answer 6

• Able to achieve local or systemic effects
• Can achieve sustained, controlled doses of the drug
• Avoids first pass metabolism

Question 7

Benefits of inhalation

Answer 7

• Drug delivered straight to site of action
• Rapid effect
• Available in small doses
• Little systemic absorption
• Reduced adverse effects

Question 8

Factors which affect bio-availability

Answer 8

• Formulation
• Ability to pass physiological barriers
• GI effects (motility, food, illness)
• First pass metabolism

Question 9

Describe Buccal drug delivery

Answer 9

Putting a pill or tablet under the lip

Question 10

Describe Sublingual drug delivery

Answer 10

Drug being deposited under the tongue

Question 11

Describe Oral drug delivery

Answer 11

Swallowing medicine

Question 12

Describe Rectal drug delivery

Answer 12

Up the butt

Question 13

List some mechanisms of renal drug excretion.

Answer 13

Glomerular filtration
Active tubular secretion
Passive tubular reabsorption

Question 14

Give an account of Glomerular Filtration.

Answer 14

Excess fluid and waste is excreted out of circulation by the glomerulus and directed into the tubules in the kidneys.

Question 15

Give an account of active tubular secretion.

Answer 15

Some drugs are actively secreted into the proximal tubules of the kidneys. This is the primary method of excretion for protein bound cationic and anionic drugs.

Question 16

Give an account of passive tubular reabsorption.

Answer 16

As filtrate moves down the tubules it becomes more concentrated, as does the drug(s) which may be dissolved in it. This means the body is able to passively reabsorb drugs from the tubules.