08.19 - Drug Tx of Bacterial Infections (Sweatman) - Questions Flashcards
Unproductive cough in pneumonia suggests
Viral or mycoplasma etiology
Most important factor in successful treatment of pneumonia is
early intervention
2 most common causes of nosocomial pneumonia
S Aureus; P Aueruginosa
Most common cause of pneumonia in DM or Alcoholic
Klebsiella Pneuminae
Most common etiology of pneumonia in 18-40 yo
Mycoplasma Pneumoniae
Tx of Legionnaires
Azithro or Carithromycin
Respiratory Quinolones
Levofloxacin, Cirpofloxacin, Moxifloxacin
Who gets Legionnaires
Men >50; Smokers/Chronic Lung Dz; Immunocompromised
Abx for Outpatient, no modifying factors
Macrolide or Doxycycline
1st gen macrolide? 2nd? 3rd?
Erythromycin, Clarithromycin, Azithromycin
For aminoglycoside, you should think
Gentamicin
Abx for Outpatient, COPD, no steroids or abx in 3 months
2nd gen Macrolide or Doxycycline
MOA for Macrolides
50s ribosomal inhibitor: Blocks translocation
MOA for Tetracyclines
30s ribosomal inhibitor: Blocks protein synthesis
MOA for Fluoroquinolones
DNA Gyrase inhibitor: Prevents DNA replication
MOA for Penicillins
Block cell wall cross-linking
MOA for Carbopenem
Blocks cell wall cross-linking
MOA for Cephalosporins
Inhibit cell wall cross-linking
MOA for Aminoglycosides
30s Ribosomal inhibitor
Resistance mech for Macrolides
Ribosomal methylation and mutation of 23S rRNA; Active efflux
Resistance for Tetracyclines
Decreased entry and increased efflux; Target insensitivity
Resistance for Fluoroquinolones
Mutation of DNA Gyrase; Active efflux
Resistance for Penicillins
Drug inactivation (b-lactamase); Altered PBPs; Decreased permeability of gram positive outer membrane; Active efflux
Resistance for Cephalosporins
Drug inactivation (b-lactamase); Altered PBPs; Decreased permeability of gram positive outer membrane; Active efflux
Resistance for Aminoglycosides
Drug inactivation ; Decreased perm of gram neg outer membrane; Active efflux; Ribosomal methylation
No etiologic agent in ___% of nosocomial pneumonia
50%
3 indicated drugs for most nosocomial pneumonia
Impipenem/Cilastin; Aztreonam; Ceftazidime
When should Vancomycin be used
MRSA
50% of isolates in hospitalized patients with aspiration pneumonia are
Gram negative enteric bacilli
Abx for Aspiration Pneumonia
Clindamycin
MOA of Clindamycin
50S ribosomal inhibitor
MOA of Vancomycin
Binds D-alanyl-D-alanine terminus of the peptide precursor units, inhibiting peptidoglycan polymerase and transpeptidation reactions
Resistance for Vancomycin
Replacement of D-ala by D-lactate
Oral bioavailability in Doxycycline and Fluoroquinolones
High, so easy to administer orally
3 important parameters for defining drug activity
AUC/MIC, Cmax/MIC, T>MIC
Characterize AUC/MIC, Cmax/MIC, T>MIC
Concentration-dependent: AUC/MIC, Cmax/MIC; Time-dependent: T>MIC
Concentration-dependent means that increase in abx conc leads to more
rapid rate of bacterial death
Time-dependent means that reduction in bacterial density is proportional to
time that concentrations exceed MIC
Concentration-dependent drugs are often given
in large doses at long intervals relative to serum half-life
Time-dependent drugs are often given
more frequently, with emphasis on need to maintain serum drug level above MIC for 30-50% of dose interval
Renally eliminated drugs (adjust for renal impairment)
Amoxicillin, Ampicillin, Cefazolin, Cefepime, Ceftazidime, Gentamicin, Imipenem, Levofloxacin, Meropenem, Piperacillin, Vacomycin
Toxicity of Amoxicillin, Ampicillin
Maculopapular Rash
Toxicity of Azithromycin
Jaundice; QT prolong
Toxicity of Cephalosporins
Cross-reactivity with penicillin hypersenstivity
Toxicity of Doxycycline
Teeth; Photo; Decr bone growth
Toxicity of Erythromycin
Same as Az + CYP3A4 inhibitor
Toxicity of Gentamicin
Nephro and Ototoxicity; Neurmuscular paralysis
Toxicity of Imipenem
Pen/ceph hypersensitivity; Seizures
Toxicity of Levofloxacin
Tendon/Cartilage
Toxicity of Linezolid
Bone marrow suppression; MAOi
Toxicity of Meropenem
Pen/ceph hypersensitivity; Seizures
Toxicity of Piperacillin
Decr coagulation
Toxicity of Vancomycin
Nephro and Ototoxicity; Red Man’s Syndrome
Abx with developmental dysfunction toxicity
Doxycycyline
Abx with unusual organ dysfunction toxicity
Gentamicin, Vancomycin, Erythromycin; Imipenem, Meropenem; Levofloxacin
Other classes, besides penicillin, with beta-lactam ring
Cephalosporin, Carbapenem
Abx caution with breastfeeding
Clarithromycin, Linezolid, Metronidazole, Piperacillin, Doxycycline
Teratogenic Abx
Clarithromycin, Doxycycline, Erythromycin, Gentamicin, Levofloxacin, Linezolid, Metronidazole, Trimethroprim
What is paired with Amoxicillin
Clavulonic Acid
What is paired with Piperacillin
Tazobactam
What is paired with Ampicillin
Sulbactam
What is paired with Imipenem
Cilastin
Function of Cilastin
Reversible, competitive inhibitor of DHP-1, which breaks down imipenem to inactive, nephrotoxic metabolites
Reversible, competitive inhibitor of DHP-1, which breaks down imipenem to inactive, nephrotoxic metabolites
Function of Cilastin
Why is Daptomycin not used for pulmonary infections
Inactivated by surfactant
Most episodes of bronchitis in young patients are
Viral
Etiology of bronchitis in most older patients
Bacterial
Most common etiology of bronchitis in smokers
H. Influenzae
4 abx indicated for bronchitis
Amoxicillin, Azithromycin, Clarithromycin, Doxycycline
Lung abcesses resolve with tx within
2 months
Gram positive cocci in lung abscesses are usually ___-aquired
Community
Gram negative bacilli in lung abscesses are usually ____-acquired
Nosocomial
Abx for community acquired lung abscess
Clindamycin
Abx for nosocomial-acquired lung abscess
Metronidazole + Ceftriaxone
Clindamycin is superior to penicillin vs
Bacteroides
For CAP, a ___ or ___ is appropriate 1st choice
Macrolide or Respiratory Quinolone
Alternative option for CAP
Amoxicillin/Clavulanate
Tx for abscesses and aspiration pneumonia should cover
Oral Anaerobes