PHARMACOLOGY - Overview

Question 1

Define pharmacokinetics

Answer 1

The study of how an organism affects the drug

Question 2

Define pharmacodynamics

Answer 2

The study of how a drug affects the organisms including the desired effect, side effects and toxic effects

Question 3

What does ADME stand for?

Answer 3

• Absorption
• Distribution
• Metabolism
• Excretion

Question 4

How does the physiochemical nature of a drug affect its absorption and distribution?

Answer 4

The solubility and ionisation status of a drug impacts its absorption and distribution

Question 5

Describe how drug solubility impacts its absorption and distribution

Answer 5

• Water soluble drugs can dissolve in cellular fluid
• Lipid soluble drugs can move through the lipid membrane

Question 6

Describe how the ionisation status of a drug can impact its absorption and distribution

Answer 6

• Weak acid drugs are unionised in acidic solutions
• Weak base drugs are unionised in alkaline solutions

this is important as charges/ionised molecules cannot pass through lipid membranes

Question 7

List three methods of drug translocation

Answer 7

• Bulk flow transfer
• Diffusional transfer
• Plasma protein binding

Question 8

What is the advantage of bulk flow drug transfer?

Answer 8

The drug moves on mass wherever the blood moves, allowing for rapid and wide distribution of the drug around the body

Question 9

What are the advantages and disadvantages of diffusional drug transfer?

Answer 9

• Slow, more complex and the drug can be blocked by cellular barriers
• More specific effect

Question 10

Drugs can be translocated via carrier mediated transfer (a form of diffusional transfer). List the different types of carrier proteins that would be involved in this process

Answer 10

• Organic cation transporters: transporyt positive molecules/ions
• Organic anion transporters: transport negative molecules/ions
• P-glycoproteins

Question 11

Which parts of the body have a particularly high concentration of carrier proteins?

Answer 11

• Blood-brain barrier
• Gastrointestinal epithelium
• Renal tubules

Question 12

Describe a negative effect associated with very lipid soluble drugs

Answer 12

Very lipid soluble drugs can sometimes build up in lipid stores which can be problematic due to the accumulation of the drug in the body

Question 13

What is the blood-brain barrier?

Answer 13

A continuous layer of epithelial cells joined by tight junctions to restrict the movement of systemic drugs in and out of the brain

Question 14

What are agonists?

Answer 14

Molecules which bind to and stimulate a receptor

Question 15

What are antagonists?

Answer 15

Molecules which bind to a receptor and block agonist action

Question 16

List the methods of enteral drug administration

Answer 16

• Oral
• Rectal

Question 17

List the methods of parenteral drug administration

Answer 17

• Sublingual
• Inhalation
• Injection

Question 18

List the methods of topical drug administration

Answer 18

• Directly onto the skin
• Directly onto mucous membranes

Question 19

Drugs used for parasite specific control have selective toxicity. Define selective toxicity

Answer 19

Selective toxicity is the property of s toxic agent to harm/eradicate one species without effecting the host species