CIS - Waller: Pneumonia, etc. Flashcards
Most likely lobar CAP? And most appropriate treatment?
strep pneumo
empiric guidelines for outpatient CAP: azithromycin or doxy (for a previously healthy patient not at risk for drug resistance)
gram stain of mycoplasma?
atypical, no stain
CURB-65 risk factors lead to what?
increased mortality
Confusion
Uremia BUN > 20
Resp rate > 30
low BP under 90/ 60
Age over 65
When do we do sputum cultures?
usually in an in-patient setting; by the time we do it in an outpatient setting it’s usually been taken care of.
when do we use clindamycin?
anaerobic infetions
when do we use trimeth-sulfameth
opportunitic infections of the immunocompromised
when do we use ceftazidime?
serious gram neg infections, and it is anti-pseudomonal
Binds DNA gyrase preventing relaxation of DNA supercoils
fluoroquinolines
Blocks protein synthesis by inhibiting translocation
macrolides
Disrupts cell membrane structure
polymyxins
Prevents initiation of protein synthesis
aminoglycosides
Prevents the attachment of aminoacyl tRNA to acceptor site
tetracyclins
Sputum gram stain shows abundant neutrophils and gram-positive diplococci.
strep pneumo.
Most narrow spectrum drug is penicillin G. Most narrow outpatient would be amoxicillin
how is penicillin G administered?
IV
not good for outpatient setting
penicillin resistant guys are often also resistant to?
macrolides, 1st and 2nd generation cephalosporin
for drug resistant strep pneumo give
fluoroquinolones, 3rd gen ceph, vancomycin, linezolid
Inpatient, Non-Intensive Care Unit Recommendations
Respiratory FQ IV or PO (levofloxacin, moxifloxacin)
-OR-
B-lactam IV (ceftriaxone, cefotaxime, or ampicillin preferred) PLUS macrolide IV (azithromycin)
During antibiotic therapy, which of the following parameters is not routinely monitored? Adverse effects Chest X-ray Fever Oral intake Respiratory rate
chest x-ray
Which of the following antimicrobial regimens does not cover atypical pathogens?
Azithromycin Ceftriaxone Doxycycline Levofloxacin plus ceftriaxone Moxifloxacin
Ceftriaxone
give it with a fluoroquinolone or macrolide in inpatient settings
Most likely gram negative bacilli VAP?
pseudomonas aeruginosa
If there is high risk of MRSA what do you want to make sure is in the treatment?
Vancomycin
Binds the bacterial 50S ribosomal subunit
macrolides
Blocks attachment of aminoacyl-tRNA to the A site
tetracyclines
Causes misreading of mRNA information
aminoglycosides
Inhibits folate synthesis
trimeth/ sulfameth
Inhibits mycolic acid synthesis
isoniazid
what increases warfarin concentration?
trimethoprim sulfamethoxazole
What is the purpose of tazobactam in the antibiotic combination piperacillin/tazobactam?
Inhibits inactivation of piperacillin by B-lactamase-producing bacteria
beta lactam with anaerobic activity?
Ampicillin/ sulbactam
a protein synthesis inhibitor with anaerobic activity
clindamycin
protein synthesis inhibitor with aerobic activity
gentamicin, e.g.
mechanism of -azoles
Inhibition of ergosterol synthesis
linezolid side effect
myelosuprression
unique side effect of voriconazole
visual disturbances: flashes of light
persistent cough following sore throat viral infection, dx?
acute bronchitis
use codeine (cough suppressant) and no antimicrobials.
when do we use antimicrobials in acute exacerbation of bronchitis?
shortness of breath
increased sputum volume OR
purulent sputum
Isoniazid (INH) MOA
MOA: inhibits synthesis of mycolic acids
when is streptomycin given for TB?
severe, life-threatening
It’s only given IV
Ethambutol (EMB) MOA
MOA: disrupts synthesis of arabinoglycan
Inhibits mycobacterial arabinosyl transferases (encoded by embCAB operon)
ADRs:
Retrobulbar neuritis (loss of visual acuity, red-green color blindness)
Rash
Drug fever
most concerning side effect of TB drugs?
hepatotoxicity
look out for elevated serum aminotransferase activity
worry about jaundice, vomiting, nausea, fatigue
biggest TB drug cause of hepatotoxicity?
Pyrazidamide
Pyrazinamide (PZA)
disrupts mycobacterial cell membrane synthesis and transport functions
Macrophage uptake, conversion to pyrazinoic acid (POA-)
Efflux pump to extracellular milieu
POA- protonated to POAH, reenters bacillus
ADRS: hepatotoxicity, GI upset, hyperururicemia (consider leaving it out with gout)
Isoniazid and acetylation
metabolized via phase 2 acetylation
slow acetylators –> accumulation
fast acetylators –> lower concentrations of isoniazid
what vitamin deficiency leads to peripheral neuropathy?
B6
important considerations before choosing an anti-TB regimen for HIV patients?
interactions between anti-retroviral therapy and rifampin; Rifampin is a P450 inducer, thus will decrease concentrations of the antivirals
Rifampin MOA
MOA: inhibits RNA synthesis
Binds B-subunit of DNA-dependent RNA polymerase (rpoB)
