Introduction to pharmacology

Question 1

What is Pharmacology

Answer 1

The science of drugs and their effect on living systems. It is also the science of what is happening to the body and to the drug itself.

Every medication we take alters the chemistry within the body by exerting a biochemical or physiological effect on the cell, tissue organ or organism.

Question 2

Drug Sources

Answer 2

Naturally Occurring:
Plants
Minerals

Derived from Animals:
Hormones

Synthetic:
Man-Made Chemicals
Genetically Engineered Substances

Question 3

Forms and Preparation

Answer 3

Enterals: Substances taken through the GI Tract. e.g. Tablets, Capsules, Suspensions, Elixirs & Syrups

Parenterals:
Substances injected into the body
Inhaled Drugs

Topicals:
Substances applied to the skin or mucous membranes
Ointments & Creams

Question 4

Drug Administration Routes

Answer 4

Intravenous/ Intraosseous
Inhaled / Nebulised
Sublingual
Buccal
Intramuscular
Rectal
Sub-Cutaneous
Oral

Question 5

Drug Administration Routes

Intravenous & Intraosseous

Answer 5

Immediate Distribution
Rapid onset of action
Allows titration to desired effect
Potentially difficult and time-consuming
Rapid onset of side effects or allergic reaction
Not Used by EAC or EMTs

Question 6

Drug Administration Routes

Inhaled

Answer 6

Gases absorbed into the blood through the lungs

Delivered directly to the site of the problem, speeding up the onset of action

Inhaled drugs are absorbed into the bloodstream and can have side effects in other parts of the body

Question 7

Drug Administration Routes

Sublingual

Answer 7

Rapid absorption through the capillary network in the base of the tongue.

Patient has to be cooperative.

Why is GTN not given orally?
Drug is broken down very quickly in the stomach, and therefore not effective if taken orally

Question 8

Drug Administration Routes

Buccal

Answer 8

Absorption via the mucus membrane of the gums and cheeks

Question 9

Drug Administration Routes

Intramuscular

Answer 9

Easy to perform
Good absorption if perfusion is good
Slow onset of action in shock
Can not ‘titrate’ to a desired level – has to be done quickly

Question 10

Drug Administration Routes

Rectal

Answer 10

Absorbed through the rectums blood vessels.

Rectal diazepam:
When an individual is fitting, this is an easier option to administer diazepam over IV.
Can only be given once.

Question 11

Drug Administration Routes

Subcutaneous

Answer 11

Morphine
Only LAS drug that is given via a subcutaneous injection is morphine
- Sickle cell crisis and EOLC
Useful for when medications must beabsorbed into the bloodstream more slowly and steadily

Question 12

Drug Administration Routes

Oral

Answer 12

Allows fast absorption of drugs, provided that there is an adequate blood supply to the GI tract

Drugs can be ‘coated’ to allow more gradual uptake and steady blood levels

Many drugs cause GI upset

Question 13

Terminology: Presentation

Answer 13

The form and strength of the drug

Question 14

Terminology: Therapeutic effects/actions

Answer 14

The way in which the drug works

Question 15

Terminology: Indications

Answer 15

When the drug should be used

Question 16

Terminology: Contra-indications

Answer 16

When administration of the drug might be dangerous

Question 17

Terminology: Cautions

Answer 17

Special circumstances where extra care needs to be taken

Question 18

Terminology: Side Effects

Answer 18

Unpleasant effects that the patient might experience

Question 19

Terminology: Tolerance

Answer 19

Prolonged use of a drug means that higher doses are needed to achieve the same effect

Question 20

Terminology: Dependance

Answer 20

A situation in which the patient is unable to function normally without the drug

Question 21

Pharmacokinetics

Answer 21

What the body does to the drug

Question 22

Pharmacokinetics: Absorption

Answer 22

How the drug enters the blood stream

Question 23

Pharmacokinetics: Distribution

Answer 23

Once in the circulation, drugs are distributed evenly throughout the body

simple diffusion - only if the molecule or ion is lipid soluble

channel mediated

carrier mediated

Active transport - against concentration gradients

Question 24

Pharmacokinetics: Metabolism

Answer 24

How a drug is changed to an inactive compound

Question 25

Pharmacokinetics Elimination

Answer 25

Removal form the body

Question 26

Pharmacodynamics

Answer 26

What the drug does to the body

Increased or decreased cellular activity

Increased or decreased production of hormones and other active substances

Interactions between other drugs or foodstuffs:
Increase effectiveness 
Decrease effectiveness
Side effects 
Toxic effects

Question 27

patient access to medicines

Answer 27

Prescribing: on one to one basis by health care professionals.

Patient Specific Directions: administration to a specific individual.

Patient Group Directions: administration to a group of patients who fit the criteria in PGDs.

Other exemptions: midwives, optometrists - sell, supply and / or administer specific medicines directly to patients -exemptions are still valid and are used in practice.

Question 28

Legal definition of a Patient Group Direction (PGD)

Answer 28

a written instruction for the, supply and / or administration of licensed medicine (or medicines) in an identified clinical situation, signed by a doctor or dentist and a pharmacist.

Question 29

Who Can Use PGDs?

Answer 29

Registered (or equivalent) members of a profession. e.g. Midwives, nurses, pharmacists, optometrists, podiatrists and chiropodists, radiographers, orthoptists, physiotherapists and ambulance paramedics.

Act within code of professional conduct.

Individual practitioners must be named.

Designated person in the organisation to assess competency, qualification and training.