Definitions

Question 1

Pharmacology

Answer 1

The study of the effect of drugs on the function of living systems

Question 2

Pharmacodynamics

Answer 2

The effects of the drug on the body

Question 3

Pharmacokinetics

Answer 3

Effects of the body on the drug, comes in 4 steps

1) Absorption
2) Distribution
3) Metabolism
4) Excretion

Question 4

Drug

Answer 4

Biologically active compount other than a nutrient or essential dietary ingredient, consumed with the intent to produce a change in the body

Question 5

Medicine

Answer 5

A chemical preparation which usually contains one or more durgs administered with the purpose of producing a therapeutic effect. Usually contain other substances to make them easier to use

Question 6

Transgenic Models

Answer 6

Models that show changes in genetics that ace a random gene inserted into its DNA ie A normal rat with a rat that has been modified

Question 7

Bioavailability

Answer 7

The fraction of administered dose that reaches the systemic circulation
- Incomplete bioavailability can be due to:
+ Incomplete absorption
+ 1st pass metabolism, where the drug passes through the system completely

Question 8

Enteral administration

Answer 8

Where drugs are absorbed by GI tract
Administration routes includes:
- Oral
- Sublingual
- Rectal
- Inhalation

Question 9

Topical administration

Answer 9

Where drugs are applied directly on
Administration routes includes:
- Skin
- Epithelial surfaces
- Mucosal

Question 10

Parenteral administration

Answer 10

Non-oral methods of drug administration ie injections
Administration routes includes:
- Subcutaneous
- Intramuscular
- Intravenous
- Intrathecal

Question 11

The apparent volume of distribution (Vd)

Answer 11

Defined as the volume of fluid required to contain the toal amount of the drug in the body at the same concentration as that present in the body

Vd = D/Cp

Vd = Volume of Distribution
D = The total amount of drug in body
Cp = Blood concentration

Vd cannot be less that the physiological volume of intravascular plasma (approx. 3L)
Can be further divided by body weight to normalise

Question 12

Prodrugs

Answer 12

Where metabolism takes the parent compound + makes it metabolically active pharmacologically

Question 13

1st Pass Metabolism

Answer 13

When metabolism begins before drugs reach general circulation/drug target

Question 14

receptor Occupation Theory

Answer 14

Generally, the drug with the higher affinity is more specfiic for that receptor

Question 15

Dissociation Constant Equation

Answer 15

Dissociation Constant = Rate of dissociation/Rate of association

Question 16

Association constant

Answer 16

Association Constant = Rate of association/Rate of dissociation

Question 17

Ki

Answer 17

Defines as the concentration of competing ligand required to displace 50% of the specific binding of the radiolignad + gives an estimate of affinity in assays

Question 18

EC50 (Half Maximal Effective Concentration)

Answer 18

The concentration of a drug that causes 1/2 the maximal effect produced by a particular drug, not a measure of efficacy, a measure of potency of an agonist, but not a measure of affinity. Also gives infoIC50 about drug selectivity

Question 19

IC50 (Half Maximal Inhibitory Concentration)

Answer 19

Concentration of antagonist required to block agonist response, dependent on assay conditions used. Approximates affinity of competitive reversible antagonists, but doesn’t tell the mechanism of the antagonist

Question 20

Dose ratio

Answer 20

Dose ratio = EC50 + Antagonist/EC50 control

EC50 control is just the agonist concentration

Question 21

The Schild Plot

Answer 21

Tells if the an antagonist is competitive and if so, an estimate of its affinity

Question 22

Phase 1 reactions

Answer 22

• Such possible reactions are to change the drug molecule structure including
  + Oxidation
  + Reduction
  + Hydrolysis

Question 23

Phase 2 reactions

Answer 23

• Involves formation of covalent bonds
• Results in water-soluble conjugates for excretion
• Products of phase 2 are predominantly inactive however in some cases activity is retained

Question 24

1st pass metabolism

Answer 24

• Where metabolism begins before the drug reaches general circuit/drug target
• Can be caused by:
  + Liver
  + Lung
  + Intestinal lumen
  + Intestinal wall