UTI CUE CARDS

Question 1

What is the Abx Creed? (MINDME)

Answer 1

> Microbiology guides therapy (where possible)
Indications should be evidence based
Narrowest Spectrum Required
Dosage appropriate to site and type of infection
Minimise duration of therapy
Ensure monotherapy in most situations

Question 2

What are the benefits of Abx?

How can the benefits be achieved?

Answer 2

> Benefit: Eradicate causative organism to cure illness

> Can be achieved by: appropriate drug choice, patient compliance with completing the abx course (choose abx that covers organism)

Question 3

What risks are associated with antibiotic use?

How can these risks be minimised?

Answer 3

> Abx spectrum related: disruption of natural flora (diarrhoea [mild], thrush [oral, vaginal], c. difficile overgrowth) and resistance - can be minimised by choosing abx for the appropriate indication, duration and drug choice (spectrum)

> Drug class specific: e.g. allergic reactions, nephrotoxicity, photosensitivity - can be minimised by appropriate drug choice and counselling on recognition/management

Question 4

How can infections be diagnosed?

Answer 4

> Signs and symptoms: dependent upon site and severity of infection (local vs. systemic)

> Laboratory Tests: microbial culture (swabs, urine, stool), organism specific tests (PCR, breath tests), WBC counts

Question 5

What are the Types of Therapy Used to Manage Infections?

Answer 5

Directed Therapy and Empirical Therapy

Question 6

What is Abx choice based on in Directed Therapy and what rules should Abx choice follow?

Answer 6

> Abx choice: demonstrated microbial cause and its abx sensitivities

> Should be: narrowest spectrum drug to which the organism is sensitive

Question 7

What is Abx choice based on in Empirical Therapy and what rules should Abx choice follow?

Answer 7

> Abx choice: most likely and/or important potential pathogen(s) and their likely abx sensitivities

> Should be: narrowest spectrum drug to treat most likely pathogen

Question 8

What factors are taken into account when treating using Empirical Therapy?

Answer 8

> Initial site of infection - common organisms for that site? can it be caused by normal flora overgrowing or moving to sterile area?

> ‘Foreign’ organisms?

> Factors that might change types of organisms present: comorbidities, immunosuppressed, anatomical abnormalities, patient location (e.g. overseas, hospital)

Question 9

What are the risks of Empirical Therapy if:

Spectrum Too Broad:
Spectrum Too Narrow:
Infection due to other organism:

Answer 9

> Spectrum Too Broad: Side effects from disturbing natural flora, promotes resistance
Spectrum Too Narrow: Therapy failure
Infection due to other organism: Therapy failure

Question 10

What are the Different Classifications of UTI and what parts of the body do they infect?

Answer 10

> Cystitis: infection involving bladder
Pyelonephritis: infection involving kidney
Urosepsis: infection of UT that results in serious systemic side effects

Question 11

What are the Types of Tests used to diagnose a UTI?

Why are these tests important?

Answer 11

> Urine Dipstick
Urine Microscopy and Culture (provides information on causative organism, abx sensitivities)

> Important to treat right organism

Question 12

How do UTIs occur?

Answer 12

> Bacteria can migrate from GI tract or groin, causes infection

Question 13

What are the most likely causative organisms of UTIs?

Answer 13

> Gram negative organisms: e. coli, pseudomonas

> Gram positive organisms: staph. saprophyticus, enterococcus

Question 14

What’s the difference between uncomplicated and complicated UTIs?

Answer 14

> Uncomplicated UTIs: adult non-pregnant women, no function or anatomical abnormalities of UT

> Complicated UTIs: associated with UT anatomical or functional abnormalities (e.g. diabetes, men, children)

Question 15

What is an Infection?

Answer 15

> Bacterial, viral, fungal
> Induces white cell response
> May induce fever
> Local effects
> May lead to sepsis

Question 16

What is Bacteraemia?

Answer 16

> Type of infection
Presence of bacteria in blood
Usually secondary infection
May lead to sepsis

Question 17

What are the Mechanisms that exist for penicillin allergies?

Answer 17

Immediate (<1 hr after administration) or Delayed (>72hrs after commencing treatment)

Question 18

Mechanisms that exist for penicillin allergies: Immediate - What the Symptoms? What are they mediated by?

Answer 18

> Symptoms: Anaphylaxis, bronchospasm, angioedema

> Mediated by IgE: cross reactivity may occur

Question 19

Mechanisms that exist for penicillin allergies: Delayed - What the Symptoms? What are they mediated by?

Answer 19

> Symptoms: Maculopapular cutaneous eruption (mild)

> Mediated by IgG and T cells: cross reactivity rare

Question 20

Explain the potential for cross-reactivity between penicillins and cephalosporins in immediate hypersensitivity and in delayed reactions

Answer 20

> Immediate Hypersensitivity: IgE may recognise beta-lactam core part of structure - some patients may cross react

> Delayed Reaction: Immune recognition is R-side chains. Selection of an appropriate abx with a different R group results in a very low risk of cross-reactivity

Question 21

Describe the Mechanism of Drug Allergies

Answer 21

1. Drug has to bind to protein (drug-protein conjugate) - this is what is recognised by immune system
2. Then it can be recognised by an IgE, T cell or IgG
3. End up with immune activation, cell/tissue damage and then hypersensitivity

Question 22

What is the Mechanism of Aminoglycoside Nephrotoxicity?

Why should we allow for a drug-free period?

Answer 22

> Involves filtration at the glomerulus, followed by receptor mediated uptake into lysosomes

> If excessive doses are administered, the lysosomal storage becomes overwhelmed and the lysosomes rupture which leads to cell death

> Allowing a drug free period ensures that the lysosomal storage doesn’t become overwhelmed

Question 23

How are aminoglycosides dosed to avoid overwhelming of lysosomal storage?

What do we do for patients with poor kidney function?

Answer 23

> Renal uptake is saturable, so high peak concentrations don’t result in overwhelming of lysosomal storage

> High peak concentrations result in increased efficacy

> Commonly dosed once daily aiming for a high peak to ensure efficacy and a low trough to prevent toxicity

> Patients with poor renal function; may need to give at intervals > 24 hrs or should be treated with a different drug

Question 24

When does the benefit of prophylaxis outweigh the risks?

Answer 24

> Patient’s natural defence against infection is weakened (e.g. immunosuppressed, surgery)

> Patient been in contact with contagious person with serious infection (e.g. meningococcal disease, HIV exposure)

> Patients with recurrent infections with known or suspected pathogens (e.g. recurrent UTI)

Question 25

Recurrent UTIs can be either?

How are recurrent UTIs managed?

Answer 25

> Can be either relapse (same organism usually within 2 weeks of completing course) or re-infection (same organism with a symptom free period of at least 1 month in between - may be different organism)

> Management: treat current infection with a longer abx course or prophylaxis

Question 26

When would you consider prophylaxis?

Answer 26

> Two or more appropriately treated infections in 6 months

> Three or more appropriately treated infections in a 12 month period

Question 27

What are non-abx management option? (of UTI [recurrent])

Answer 27

> Intra-vaginal oestrogen in post menopausal women

> Methenamine

Question 28

How do urine alkalinising agents (ural) help with UTIs?

Answer 28

> Relieves symptom of burning on urination
Doesn’t cure
Do not combine with fluoroquinolones (can precipitate in the kidney at high pH)

Question 29

What also helps antimicrobial therapy of UTI?

Answer 29

High fluid intake and complete bladder emptying assist antimicrobial therapy of UTI

Question 30

How does cranberry help in UTIs?

Answer 30

Prevent E.coli adhesion to uroepithelium