8.4 Pharmacological Management of Respiratory Infection Flashcards
What was the mortality rate of TB before anti-TB treatment
~50% (!)
Did increased duration of antibiotic therapy decrease or increase relapse rates of TB?
Decrease
Should you ever use a single antibiotic when treating tuberculosis?
No; this could lead to resistance
Should you ever add a single antibiotic to a failing TB regimen?
No; this could lead to resistance
Are tuberculosis drugs free in Australia?
Yes
What is DOT in TB treatment? Why is it important?
- DOT (directed observed therapy) is when a trained healthcare worker or someone else (not family member) watches the patient swallow each dose of their drugs
- This prevents antibiotic resistance, relapse, and improves mortality rates
What are the two phases of pharamcological TB treatment?
- Intensive phase (bactericidal)
- Continuation phase (sterilisation)
What occurs during the intensive (bactericidal) phase of TB treatment? How long does it last?
- Kills of actively dividing TB population
- Lasts for at least 2 months
What occurs during the continuation phase (sterilisation) of TB treatment? How long does it last?
- Semi-dormant/dormant persistor cells are formed during the intensive phase; this phase kills them
- Lasts for at least 4 months
What is the most potent drug used during the bactericidal phase of TB treatment?
Isoniazid
What is the most potent drug used during the sterilisation phase of TB treatment?
Rifampicin
List some important ways of ensuring treatment completion during tuberculosis
- DOT
- Developing a partnership with the patient
- Monitoring for side effects
- Patient support measures
Under what circumstances should we especially consider DOT for TB treatment?
- All infectious
- Drug resistant cases
- Cultural/language issues
- Elderly/mental health issues etc.
Is TB treatment short or long in duration? How does this impact the probability of developing antibiotic resistance?
- Long in duration
- Provides many opportunities for interruption (acquired resistance)
How can healthcare providers directly CAUSE antibiotic resistance to TB
By ‘breaking the rules’ (using/substituting one drug). Bad idea.
What patient factors can cause drug resistant TB?
- Malabsorption
- Non-adherence
What is the main source of drug-resistant TB?
Transmission from others
Approach to treatment of drug-resistant TB
- Start with 4-5 drugs of proven susceptibility (that they haven’t been given before)
- Keep testing until it works
How do the drugs used in drug-resistant TB differ from those in regular TB?
- More toxic
- More expensive ($100k vs $400)
Does drug resistant TB require a mulidisciplinary approach of treatment?
Yes
How many susceptible drugs should you use at once during TB treatment of regular, susceptible TB?
3-4
Describe the radiological presentation of lobar pneumonia
Consolidation of a single lung lobe
Describe the radiological presentation of bronchopneumonia
Patchy; involving one or several lobes
Describe the radiological presentation of interstitial pneumonia
Interstitial inflammation histologically and radiologically
Describe the radiological presentation of miliary pneumonia
Millet seed like opacities (Tb)
Describe the investigations you could do in a patient with suspected pneumonia
- CXR +/- CT chest
- Blood culture
- Sputum microscopy and culture
- Viral PCR
- Pleural fluid aspirate and culture
Why is it important to determine the aetiology of community acquired pneumnonia?
- Public health reporting/epidemiology
- Providing directed therapy
- Adjusting when initial empiric therapy is unsuccessful
List some test findings that provide a definite aetiology of pneumonia
- Isolation of bacterial pathogens from blood or pleural fluid
- Isolation of legionella from respiratory secretions (it’s not usually there)
- Legionella antigen in urine
Can the aetiology of pneumonia be found in a majority of cases?
No, over half cannot.
Should you delay antibiotic treatment in order to gather specimens for pneumonia diagnosis? Why not/why?
- No, you would not
- This can have very bad outcomes
A patient has no signs of lung consolidation on x-ray, but is coughing and spluttering. Do you give antibiotics? Why/why not?
- No you don’t
- They probably have a virus
- Don’t give antibiotics unnecessarily
In pnuemonia treatment, do we generally prefer antibiotics with a wide or thin therapeutic window (initially)?
Wide
In a patient with severe pneumonia, do we prefer bactericidal or bacteriostatic antibiotics?
Bactericidal
If you know which bacteria is causing a patient’s pneumonia, should you use broad spectrum or thinner spectrum antibiotics?
Thin; Charlie-Munger strategy
How soon after clinical improvement of pneumonia should you switch to oral antibiotics?
ASAP
Which has a broader spectrum: amoxycillin or penicillin?
Amoxycillin
Is penicillin mostly able to kill gram-positive or gram-negative bacteria?
Gram positive
What is a common antibiotic than can be used instead of penicillin if they are allergic?
Cephalosporins
Is cephalosporin used as a first-line antibiotic? Why/why not?
- No
- It can cause side effects including resistance and infection
Macrolides suffix
-mycin
What type of antibiotics could you use if you suspected that a patient had “atypical” tuberculosis?
- Macrolides
- Tetracyclin
Macrolides side effects
- GI side-effects
- Hepatitis (erythomycin)
Tetracycline suffix
-cycline
What % of pneumonia-causing bacteria are fully penicillin susceptible? What % need a higher dose, and what % are fully resistant?
Fully susceptible: 80%
Higher dose: 19%
Fully resistant: 1%
Are antibiotics more likely to negatively impact pregnant women in early or late pregnancy?
Late
What immunisations should be considered for pneumonia patients?
- Influenza
- COVID-19
- Pneumococcal
What is pneumococcal disease?
Any disease caused by strep pneumoniae
