MICROBIOLOGY- Principles of antibiotic therapy Flashcards
Where is the largest percentage antibiotics prescribed
In general practice (71%)
What percentage of total antibiotic consumption is carried out in dental practices?
3%
Has there been an increase or decrease in antibiotic prescriptions in dental practices?
There has been a 19.5% decrease
What is antimicrobial stewardship?
It is an overarching term for systems and processes to optimise the use of antimicrobials and thereby improve patient outcomes and reduce antimicrobial resistance
State the 3 basic principles of antibiotic use
The antibiotic prescribed should be:
- Clinically effective
- Safe
- Cost effective
When can antimicrobial agents be given?
- To treat infection
2. To prevent infection (prophylaxis)
When deciding if you need to prescribe antibiotics what questions do we need to ask?
- Is an infection present?
- Is the diagnosis clear?
- Is an antibiotic indicated? Will it improve the infection?
- What are the likely causative organisms
- Have appropriate specimens been collected before starting therapy
- Which is the best antibiotic
- Is a combination of antibiotics indicated
- What is the most appropriate route of administration
- Dose?
- Is antibiotic resistance likely
- Patient consideration
Antibiotic treatment can be D_______ or E_________
Directed or empirical
What is empirical antibiotic treatment
When you prescribe antibiotics based on your knowledge of the likely pathogens that may be causing the infection (Educated guess work)
What is direct antibiotic treatment
When you know exactly which pathogens are causing the infection and give antibiotics to fight them
What can we use to sample which pathogens are causing an infection?
- Pus
- Bone
- Blood cultures
- CSF (cerebrospinal fluid)
- Gram stain of fluid from normal sterile sites
When is combination antibiotic therapy indicated?
- Febrile lwukpaenic
- Infections with multiple organisms
- Limiting/preventing emergence of resistance
What are the problems associated with combination antibiotic therapy
- Increased risk of toxicity, allergy and colonisation with resistant organism
- Antagonism
- Increased cost
What is pharmacokinetics?
It explores what the body does to a drug
What factors determine the most effective route of administration for a drug?
- How the body handles a drug influences how it can be administered
- Indication for the drug
- Severity of infection
- Safe swallow
- Concurrent medication
List some pharmacodynamic considerations we take when deciding drug dosage
- Concentration
2. Time
Why is drug dosage important
- To reduce side effects, superinfection and minimise cost
2. To make sure antibiotic will actually help
What do we need to consider when setting a drug dosage?
- Specific dosed for neonates, children and adults
- Organism consideration
- Site of infection
What is elimination half life?
The time taken for plasma concentration to reduce by 50%
Why is the elimination half life of a drug important
As it influences dosing intervals (how often the drug needs to be given)
When choosing an antibiotic do we prefer broad spectrum or narrow spectrum?
We aim to give the narrowest spectrum antimicrobial active against the causative organism
Name the 2 types of antibiotic resistances
- Acquired resistance
2. Selection of resistant organisms
Give examples of how bacteria can become resistant
- Decreased permeability
- Absent antigen or target for the antibiotic
- Mutation leading to the antibiotics target changing
- Enzymatic degradation of the antibiotic
- Some bacteria can efflux the drug effectively
What patient considerations do we need to take before prescribing antibiotics
- Pregnancy and lactation
- Other medical problems
- Renal failure
- Liver failure
When should you start antibiotic treatment
ONLY if there is clinical evidence of a bacterial infection
What does AMR stand for?
Antimicrobial resistance
What does AMS stand for?
Antimicrobial stewardship
When should you review the effectiveness of the antibiotic you’ve prescribed?
48 hours
Modify
Review again at 72 hours
What is prophylaxis?
When antibiotics are given to prevent infection following a procedure
Describe the antibiotics that are used in a prophylaxis way
Single dose with a spectrum to cover the most likely pathogens
