MICROBIOLOGY- Principles of antibiotic therapy

Question 2

Where is the largest percentage antibiotics prescribed

Answer 2

In general practice (71%)

Question 3

What percentage of total antibiotic consumption is carried out in dental practices?

Answer 3

3%

Question 4

Has there been an increase or decrease in antibiotic prescriptions in dental practices?

Answer 4

There has been a 19.5% decrease

Question 5

What is antimicrobial stewardship?

Answer 5

It is an overarching term for systems and processes to optimise the use of antimicrobials and thereby improve patient outcomes and reduce antimicrobial resistance

Question 6

State the 3 basic principles of antibiotic use

Answer 6

The antibiotic prescribed should be:

1. Clinically effective
2. Safe
3. Cost effective

Question 7

When can antimicrobial agents be given?

Answer 7

1. To treat infection

2. To prevent infection (prophylaxis)

Question 8

When deciding if you need to prescribe antibiotics what questions do we need to ask?

Answer 8

1. Is an infection present?
2. Is the diagnosis clear?
3. Is an antibiotic indicated? Will it improve the infection?
4. What are the likely causative organisms
5. Have appropriate specimens been collected before starting therapy
6. Which is the best antibiotic
7. Is a combination of antibiotics indicated
8. What is the most appropriate route of administration
9. Dose?
10. Is antibiotic resistance likely
11. Patient consideration

Question 9

Antibiotic treatment can be D_______ or E_________

Answer 9

Directed or empirical

Question 10

What is empirical antibiotic treatment

Answer 10

When you prescribe antibiotics based on your knowledge of the likely pathogens that may be causing the infection (Educated guess work)

Question 11

What is direct antibiotic treatment

Answer 11

When you know exactly which pathogens are causing the infection and give antibiotics to fight them

Question 12

What can we use to sample which pathogens are causing an infection?

Answer 12

1. Pus
2. Bone
3. Blood cultures
4. CSF (cerebrospinal fluid)
5. Gram stain of fluid from normal sterile sites

Question 13

When is combination antibiotic therapy indicated?

Answer 13

1. Febrile lwukpaenic
2. Infections with multiple organisms
3. Limiting/preventing emergence of resistance

Question 14

What are the problems associated with combination antibiotic therapy

Answer 14

1. Increased risk of toxicity, allergy and colonisation with resistant organism
2. Antagonism
3. Increased cost

Question 15

What is pharmacokinetics?

Answer 15

It explores what the body does to a drug

Question 16

What factors determine the most effective route of administration for a drug?

Answer 16

1. How the body handles a drug influences how it can be administered
2. Indication for the drug
3. Severity of infection
4. Safe swallow
5. Concurrent medication

Question 17

List some pharmacodynamic considerations we take when deciding drug dosage

Answer 17

1. Concentration

2. Time

Question 18

Why is drug dosage important

Answer 18

1. To reduce side effects, superinfection and minimise cost

2. To make sure antibiotic will actually help

Question 19

What do we need to consider when setting a drug dosage?

Answer 19

1. Specific dosed for neonates, children and adults
2. Organism consideration
3. Site of infection

Question 20

What is elimination half life?

Answer 20

The time taken for plasma concentration to reduce by 50%

Question 21

Why is the elimination half life of a drug important

Answer 21

As it influences dosing intervals (how often the drug needs to be given)

Question 22

When choosing an antibiotic do we prefer broad spectrum or narrow spectrum?

Answer 22

We aim to give the narrowest spectrum antimicrobial active against the causative organism

Question 23

Name the 2 types of antibiotic resistances

Answer 23

1. Acquired resistance

2. Selection of resistant organisms

Question 24

Give examples of how bacteria can become resistant

Answer 24

1. Decreased permeability
2. Absent antigen or target for the antibiotic
3. Mutation leading to the antibiotics target changing
4. Enzymatic degradation of the antibiotic
5. Some bacteria can efflux the drug effectively

Question 25

What patient considerations do we need to take before prescribing antibiotics

Answer 25

1. Pregnancy and lactation
2. Other medical problems
3. Renal failure
4. Liver failure

Question 26

When should you start antibiotic treatment

Answer 26

ONLY if there is clinical evidence of a bacterial infection

Question 27

What does AMR stand for?

Answer 27

Antimicrobial resistance

Question 28

What does AMS stand for?

Answer 28

Antimicrobial stewardship

Question 29

When should you review the effectiveness of the antibiotic you’ve prescribed?

Answer 29

48 hours
Modify
Review again at 72 hours

Question 30

What is prophylaxis?

Answer 30

When antibiotics are given to prevent infection following a procedure

Question 31

Describe the antibiotics that are used in a prophylaxis way

Answer 31

Single dose with a spectrum to cover the most likely pathogens