Bacterial Infections of the Lung Flashcards
Pneumonia is infection of what part of the RT?
lower (respiratory bronchioles, alveoli)
What are the symptoms of pneumonia?
- FEVER, cough, and sputum production
- Dyspnea
- Chest infiltrates
THE most important factor in successful pneumonia treatment is what?
EARLY intervention, cultures from blood and sputum to
identify the infective organism can be obtained after beginning broad, empiric treatment
What is the most likely cause of community acquired pneumonia (CAP) in patients 0-6 weeks of age?
Group B strep or E. Coli
What is the most likely cause of community acquired pneumonia (CAP) in patients 6 weeks to 18 years of age?
Viruses, Mycoplasma pneumoniae, Chlamydia pneumoniae,
What is the most likely cause of community acquired pneumonia (CAP) in patients 18-40 years of age?
Mycoplasma pneumoniae, Strep pneumo
What is the most likely cause of community acquired pneumonia (CAP) in patients 40-65 years of age?
Strep pneumo, Haemophilus influenzae, anaerobes and viruses,
What is the most likely cause of community acquired pneumonia (CAP) in patients over 65 years of age?
Strep pneumo, viruses, anaerobes
What is the most likely cause of nosocomial pneumonia?
Staph aureus or Pseudomonas aeruginosa
Alcohol use attenuates lung function. How?
Chronic alcohol drinkers have decreased
saliva production, an important component of mucosal defense.
Diabetes also increases the risk of pneumonia. How?
Possibly because the disorder neutralizes the effects of protective proteins on the surface of
the lungs.
What is the most likely cause of pneumonia in diabetics or alcoholics?
Klebsiella
Immunodeficient patients are at risk of infection from what organisms?
- CMV
- Aspergillus and Pneumocystis
Describe Legionalle Pneumophilia
a gram negative aerobe that thrives in aquatic environment and loves water between 25-42 C
What patient population is most at risk for pneumonia caused by legionella (Legionnaires Disease)?
- Men over 50
- Smokers or those with COPD
- Immunocompromised
What is commonly used to treat legionnaires pneumonia?
- erythromycin
- azithromycin
- “respiratory” quinolone”
These drugs have good dosing characteristics and the advantage of easily
achieving good conc. in pulmonary tissues.
What are some ‘respiratory’ quinolones?
-levofloxacin, cipro, or moxifloxacin
What is a major possible DD interaction in patients taking macrolides?
rifampin
What is the DOC for outpatient CAPs with no modifying factors?
any macrolide or doxycycline
What is the DOC for outpatient CAPs with COPD who HAVE taken steroids or antibiotics in the past 3 months ?
Fluoroquinolone or amox/clav or clarithromycin +- cephalosporin
same for a nursing home patient
What is the DOC for outpatient CAPs with COPD who HAVE NOT taken steroids or antibiotics in the past 3 months ?
clarithromycin or doxycycline
What is the DOC for hospital ward CAPs?
fluroquinoline or amox/clav or clarithro/azithromycin +- cephalosporin
What is the DOC for ICU CAPs?
3rd gen cephalosporin +- macrolide or piperacillin/tazo or fluoroquinolone
What is the DOC for ICU CAPs with a risk of P. aeruginosa?
ciprofloxacin + B-lactam OR
macrolide + (amino, ceftazidime, cefepime, meropenem, or piper/taz)
In nocosomial pneumonia, vanco is reserved for what?
MRSA
Gram+ cocci being the cause of nocosomial pneumonia is more common in what patients?
- ICU
- DM
- Head trauma
What are the DOC for nocosomial pneumonia?
- Imipenem/Cilastin
- Aztreonam
- Ceftazidime (Cefepime)
- Vanco (poor bioavailability, give IV)
What is aspiration pneumonia?
When aspiration of gastric acid, a foreign body or normal oropharyngeal secretions give rise to pneumonia
When are oropharyngeal secretions most likely to cause aspiration pneumonia?
in reduced consciousness and long term intubation
Most of the causative organisms for aspiration pneumonia are ____
gram negative enteric bacilli (50%), then anaerobes and S. aureus
What is the DOC for aspiration pneumonia?
clindamycin or ampicillin/sulbactam
How does clindamycin work?
50s ribosomal inhibitor blocking translocation
What are some situations in which PO administration would not be best?
- presence of food or other chelating drugs in GI
- Hypotension shunts blood away from GI
What does ‘concentration dependence’ mean in terms of drugs?
bacterial death is proportional to conc (i.e. fluoroquinolone or aminoglycosides), whereas time-dependent antibiotics are dependent on duration in serum (B-lactams)
How are conc dependent drugs given?
these are often given in large doses (relative to the MIC) at long intervals relative to the serum half life for the agent.
How are time dependent antibiotics given?
usually dosed more frequently, with an emphasis
on the need to maintain the serum drug level above the MIC for 30-50% of the dose
interval.
Which drugs are not predominantly renally eliminated?
- azithromycin/erythromycin
- ceftriaxone
- clindamycin
- doxycycline
- linezolid
What are some AEs of doxycycline?
- teeth discolorization
- photosensitivity
- stunted bone growth
What are some AEs of vance?
nephro and ototoxicity and Red Man’s syndrome
What are some AEs of levofloxacin?
-tendon rupture in adults and cartilage damage in young children
What are some AEs of erythromycin?
- CYP3A4/Pgp inhibitor
- Jaundice
- QT prolongation
What are some AEs of gentamicin?
nephro and ototoxicity and neuromuscular paralysis
What are some AEs of linezolid?
- bone marrow suppression
- non-specific MAO inhibitor
What is the rational of adding clavulanic acid to amoxicillin, tazobactam to piperacillin, and sulbactam to ampicillin?
the are irreversible inhibitors of bacterial beta-lactamases
Why is cilastin given with Imipenem?
it is a reversible, competitive inhibitor of renal dehydroepeptidase-1 (DHP-1), which breaks down Imipenem to NEPHROtoxic metabolites
Why is Daptomycin not used to treat pneumonia even though it has greater activity than vance vs. some gram positive organisms?
The drug activity is directly inhibited by the presence of pulmonary surfactants.
What are the most common causes of bronchitis in young patients?
viral
What is the most common causes of bronchitis in smokers?
H. influenzae
What is the most common causes of bronchitis in elderly patients with comorbidites?
bacterial (mycoplasma pneumoniae, Strep pneumo, H. influenzae)
DOC for bronchitis?
- amoxi/clav
- azithro/clarithro
- doxycycline
DOC for resistant bronchitis?
Cipro
How is lung abscess treated?
Treatment initially involves IV drug therapy with transition to an 2 month oral regimen after a couple of weeks.
DOC for lung abscess?
Although penicillin has been considered as the drug of choice, clindamycin has proven superior, primarily because of the emergence of penicillin-resistant Bacteroides.
Other drug choices for lung abscess?
Metronidazole should not be used alone due to incomplete coverage, but may be used with a third generation cephalosporin for nocosomial infection
