Anti-bacterials Flashcards
unproductive cough among the symptoms of pneumonia suggests what about the origin?
Viral or Mycoplasma etiology
2 most likely organisms in HAP (hospital acquired pneumonia)
S. aureus
P. aeruginosa
The main causes of pneumonia infections vary by age. Name the most likely pathogen to cause community acquired pneumonia in these age groups:
- 0-6 weeks
- 6 wks - 18 yrs
- 18-40 yrs
- 40-65 yrs
- > 65 yrs
- 0-6 weeks - Group B Strep (strep agalacticae from mom’s vagina)
- 6 wks-18 yrs = Viruses or Mycoplasma pneumoniae
- Mycoplasm pneumoniae
- 40-65 = Strep pneumoniae, H. flu
- > 65 yrs = Strep pneumoniae
Why does chronic alcohol use predispose you to community acquired pneumonia?
Chronic alcohol use causes decreased saliva production, an important part of mucosal defense.
Other than alcoholics and smokers, people with what condition are pre-disposed to pneumonia?
Diabetics - the disease neutralizes the effects of protective proteins on the lung surface.
60 year old man with COPD, an alcohol problem and a 40 pack year history comes in complaining of cough, chest pain, hemoptysis, watery diarrhea, and confusion. What is the etiology of his disease?
Legionella pneumophila
Legionnaire’s Disease is characterized by pneumonia, fever, GI, and CNS symptoms.
More common in men 50+ who smoke and drink, or have a chronic lung disease.
How do you treat Legionnaire’s?
Azithromycin (3d generation macrolide) or a Respiratory Fluoroquinolone (Levofloxacin)
You have a case of outpatient pneumonia with COPD. What is the first question you ask, and how does that influence the drugs you will give them?
Have they been on steroids or antibiotics in the past 3 months?
NO- 2nd gen Macrolide - Clarithromycin or Doxycycline
YES - Fluoroquinolone
or amoxicillin/clavulanic acid
+/- cephalosporin
Why do you care if the COPD patient has been on steroids or antibiotics?
Messes with their normal flora levels, so you give them different things.
Name the 3 generations of macrolides.
Erythromycin
Clarithromycin
Doxycycline
MOA of Macrolides
50s ribosomal inhibitor - mRNA translation
When you think tetracyclines and the lung, which one would you prescribe and what the MOA of all tetracyclines?
Doxycycline
30s ribosomal inhibitor
MOA of Fluoroquinolones
DNA gyrase inhibitor, preventing DNA replication
What is the respiratory Fluoroquinolone?
Levofloxacin
What combos of penicillins do you prescribe someone with community acquired pneumo?
Amoxicillin + clavulanic acid
Piperacillin + tazobactam (worse infections)
What is the MOA of carbopenems?
Block cell wall cross-linking
it’s a B-lactam
Name the 1-3 generations of cephalosporins and their mechanism.
1 - Cefazolin, cephalexin
2 -Cefuroxime
3 - Ceftriaxone -works on both gram + and -
What are the 4th generation cephalosporins with anti-pseudomonas activity?
CEFIPIME
CEFTAZIDIME
MOA of aminoglycosides.
30s inhibitor
Aminoglycosides and Tetracyclines are the 30s inhibitors
Name some aminoglycosides.
Gentamicin, Neomicin, Streptomycin
FACT: Aminoglycosides are synnergistic with B-lactams. How?
Because B-lactams increase the uptake of aminoglycosides by breaking the cell wall of gram + bugs
MOA of cephalosporins.
Inhibit cell wall cross-linking. B-lactams.
Less susceptible to penicillinases.
Later generations (3rd) Get through the porins of gram negative bacteria to reach their cell wall.
What drugs do you give someone with S. aureus Hospital-acquired pneumonia?
Impenem/Cilastatin
Atrezonam (B-lactam monobactaom)
Ceftazidime or Cefipime (4th gen. cephalosporins)
What is the last resort, for MRSA?
Vancomycin
How is Vancomycin administered?
IV - very poor oral bioavailability