Kinder Abx Flashcards
Common Infectious Agents: Outpatient
Streptococcus pneumoniae Mycoplasma pneumoniae Haemophilus influenzae Chlamydophila pneumoniae Respiratory viruses
Common Infectious Agents: Inpatient (non-ICU)
S. pneumoniae M. pneumoniae C. pneumoniae H. influenzae Legionella spp Aspiration Respiratory viruses
Common Infectious Agents: Inpatient (ICU)
S. pneumoniae Staphylococcus aureus Legionella spp Gram-negative bacilli H. influenzae
Infecting Organisms & Disease States
Underlying bronchopulmonary disease:
H. influenzae
Moraxella catarrhalis
+ S. aureus during an influenza outbreak
Chronic oral steroids or severe underlying bronchopulmonary disease, alcoholism, frequent antibiotic use:
Enterobacteriaceae
Pseudomonas aeruginosa
Classic aspiration pleuropulmonary syndrome in alcohol/drug overdose or in seizures with gingival disease or esophageal motility disorders:
Anaerobes
Drug-resistant S. pneumoniae Risk Factors
Age < 2 years or > 65 years B-lactam use within previous 3 months Alcoholism Immunosuppressive illness or therapy Exposure to child at day care
Antimicrobial Coverage for Outpatient, Previously Healthy Pts
Macrolide PO (azithromycin, clarithromycin) Doxycycline PO
Antimicrobial Coverage for Outpatient, At Risk for DRSP
Respiratory fluoroquinolone PO (levofloxacin, moxifloxacin, gemifloxacin)
B-lactam PO [high dose amoxicillin or amoxicillin-clavulanate preferred (alternates: ceftriaxone, cefuroxime)] PLUS a macrolide PO
Antimicrobial Coverage for Outpatient, Regions with high rate (> 25%) of macrolide resistant S. pneumoniae
Consider alternatives
Antimicrobial Coverage for Inpatient, non-ICU
Respiratory FQ IV or PO (levofloxacin, moxifloxacin)
B-lactam IV (ceftriaxone, cefotaxime, or ampicillin preferred) PLUS macrolide IV (azithromycin)
Antimicrobial Coverage for Inpatient, ICU
B-lactam IV (ceftriaxone, cefotaxime, or ampicillin/sulbactam preferred) PLUS azithromycin IV OR a respiratory FQ (levofloxacin, moxifloxacin)
Modified Empiric Regimen for Pseudomonas risks
Structural lung disease (bronchiectasis)
Repeated COPD exacerbations
Frequent corticosteroid and/or antibiotic use
Prior antibiotic therapy
Pseudomonas Risks Treatments
Anti-pseudomonal B-lactam IV (piperacillin-tazobactam, cefepime, imipenem, meropenem) PLUS either ciprofloxacin or levofloxacin Or B-lactam PLUS: An aminoglycoside (gentamicin) AND azithromycin An aminoglycoside AND anti-pseudomonal fluoroquinolone
CA-MRSA risks
End-stage renal disease (dialysis)
Injection drug abuse
Prior influenza
Prior antibiotic use (especially FQ)
CA-MRSA Treatments
Add vancomycin IV or linezolid
Panton-Valentine leucocidin necrotizing pneumonia: add clindamycin or use linezolid
Pseudomonas as MDR
Resistance caused by multiple efflux pumps
Decreased expression of outer membrane porin channel
Increasing resistance to: piperacillin, ceftazidime, cefepime, imipenem, meropenem, aminoglycosides, fluoroquinolones
Other MDRs
Klebsiella intrinsically resistant to ampicillin and can acquire resistance to cephalosporins and aztreonam ESBL production
Enterobacter high frequency of developing resistance to cephalosporins during treatment
These bacteria may carry plasmid mediated AmpC-type enzymes (ESBL) which are carbapenem susceptible but CONCERNED about resistance
May become resistant by loss of an outer membrane porin
MRSA & DRSP
MRSA
> 50% of ICU infections caused by S. aureus methicillin resistant
PBPs with reduced affinity for B-lactams
Concern for linezolid resistance but still rare
DRSP
Altered PBP
ALL MDR strains in US currently susceptible to vancomycin and linezolid
Empiric Therapy – Early Onset
Potential pathogens:
S. pneumoniae
H. influenzae
MSSA
Sensitive gram-negative: E. coli, K. pneumoniae, Enterobacter spp, Proteus spp, Serratia marcescens
Treatment:
Ceftiaxone OR FQ (levofloxacin, moxifloxacin, ciprofloxacin) OR ampicillin/sulbactam OR ertapenem
Empiric Therapy – Late Onset
Potential pathogens (MDR): P. aeruginosa K. pneumoniae (ESBL+) Acinetobacter MRSA Treatment: Antipseudomonal cephalosporin (cefepime, ceftazidime) OR antipseudomonal carbapenem (imipenem, meropenem) OR B-lactam/B-lactamase inhibitor (piperacillin-tazobactam) PLUS Antipseudomonal FQ (ciprofloxacin, levofloxacin) OR aminoglycoside (amikacin, gentamicin, tobramycin) PLUS Linezolid OR vancomycin
Streptococcus pneumoniae
Non-resistant
Penicillin G, amoxicillin
Resistant
Chosen on basis of susceptibility: cefotaxime, ceftriaxone, levofloxacin, moxifloxacin, vancomycin, linezolid
Haemophilus influenzae
Non-B-lactamase producing
Amoxicillin
B-lactamase producing
2nd or 3rd generation cephalosporin, amoxicillin/cluvulanate
Mycoplasma pneumoniae
Macrolide (azithromycin, clarithromycin), tetracycline (doxycycline)
Chlamydophila pneumoniae
Macrolide (azithromycin, clarithromycin), tetracycline (doxycycline)
Chlamydophila psittaci
Doxycycline