Choose a drug class to get information about key points ID docs want you to know.
Use the antibiotic spectrum index to identify narrow vs. broader drugs
Group A and B streptococcus, syphilis drug of choice
Neutropenia with prolonged use, allergy
Methicillin susceptible S. aureus produces a beta lactamase most often for this so doesn’t cover this organism and also does not cover for methicillin resistant S. aureus
Best drug for methicillin-susceptible Staphylococcus aureus (MSSA); superior drug than vancomycin for documented MSSA
Neutropenia with prolonged use, allergy, thrombophlebitis
Doesn’t cover enterococcus and methicillin resistant S. aureus (MRSA)
Check local antibiogram for E. coli to amoxicillin and amoxicillin/ clavulanate; E. faecalis, S. pneumoniae, Group A and B streptococcus
Neutropenia with prolonged use, allergy. Amoxicillin/clavalanate is associated with more diarrhea
Amoxicillin alone does NOT cover S. aureus, need beta-lactamase inhibitor!
This class (without beta-lactamase inhibitors) does not cover enteric gram negatives other than a select few
Doesn’t cover methicillin resistant S. aureus
Better anaerobic coverage including gut flora with amoxicillin/clavulanate and ampicillin/sulbactam
beta-lactamase inhibitors (clavulanate, sulbactam, tazobactam) do not cross the blood brain barrier
Pseudomonas, and other routine enteric gram negatives and anaerobes including Bacteroides
Good coverage for anaerobes, enteric gram negatives. Avoid prolonged use if possible, as can cause drug fevers, hepatitis. Piperacillin-tazobactam does not have good central nervous system penetration
activity against MSSA and Group A streptococcus NOT MRSA; some enteric Gram negative rods
NO cephalosporins have activity against Enterococcus or Listeria.
Doesn’t penetrate the central nervous system.
do not cross blood brain barrier, doesn’t penetrate the central nervous system.
Good enteric gram negative coverage; ceftazidime adds Pseudomonoas coverage but in exchange has no S. aureus coverage and likely less S. pneumoniae coverage than ceftriaxone).
NO cephalosporins have activity against Enterococcus or Listeria
Ceftriaxone can cause biliary sludging in neonates and can react with calcium in TPN formulations causing a solid precipitant in neonates
ceftriaxone: dose dependent central nervous system penetration
Cefoxitin and Cefotetan cover anaerobes. Activity for MSSA and Group A Stretptococcus and a bit more E. coli and Klebsiella species than first generation cephalosporins
NO cephalosporins have activity against Enterococcus or Listeria: resistance is via. Cefoxitin and Cefotetan cover anaerobes
Typically will cover enteric gram negatives but in addition acceptable for Enterobacter spp, Citrobacter and Serratia spp; typically does including Pseudomonas coverage, but retains MSSA coverage. No anaerobic coverage!
No anaerobic coverage; good central nervous system penetration
Does cover for MRSA skin/soft tissue infections and pneumonia.
Think of ceftriaxone + vancomycin in one
Does not have significant anaerobic coverage
Gram negative aerobic bacteria only. Basically nothing else
Less cross-allergy with other b-lactam. No gram positive coverage and no anaerobic coverage
Gram + and negative organisms, anaerobes, very broad but often overused
Use sparingly! Drug of choice for an extended spectrum beta lactamase (ESBL) producing gram negative in the bloodstream.
dose dependent central nervous system penetration
Aerobic gram negatives (including some pseudomonas). Sometimes used in Tuberculosis treatment
Main role in therapy is for urinary tract infection, neonatal sepsis, and adjunct therapy for MDRO Gram negative rod infections
Not good for treating an abscess
Oto and nephrotoxic
poor central nervous system penetration, poor lung penetration
excellent urinary tract penetration
Gram + aerobic cocci, anaerobic organisms
Oral anaerobes
no Enterococcus, no gram negatives
High rates of C. difficile in the adult population, less in kids.
irrelevant central nervous system and urinary tract penetration
Gram positive bacteria
Drug of choice for MRSA sepsis
Plasmid mediated gene (van A) carried by Enterococcus species confers vancomycin resistance
*Less bactericidal than b-lactams
dose dependent central nervous system penetration, poor lung penetration (potentially treatment limiting in pneumonia)
Mycoplasma, Chlamydophila, Legionella, Bordatella, GAS, H. pylori, and some and some gram negative.
Not good for **azithro with more gram negative activity (h. pylori, salmonella, shigella)
Some strains of staphylococci (MSSA, MRSA), streptococci, Nocardia
Drug of choice for Stenotrophomonas
Useful oral option for ESBL-producing Gram negative bacteria
salmonella/shigella.
*Causes hypersensitivity reactions, occasionally agranulocytosis and/or thrombocytopenia
Rickettsia, Chlamydia, Ehrlichia, B. burgdorferi, mycoplasma
MSSA/MRSA
many gram negative organisms
Decreased permeability
*Generally not used (unless needed) in those under 8
MTB, S. aureus, N. meningitidis, H. influenzae, Legionella, Pseudomonas
Only needs one step to develop resistance; don’t use it alone!
Anaerobic bacteria and some protozoa (Entamoeba histolytica, Trichomonas, Giardia)
Peripheral neuropathy, GI complaints, metallic taste
Don’t use with EtOH
Gram negative organisms, including Pseudomonas (only PO option), less activity against gram + organisms; new gen more S. pneumoniae coverage
Mutations of DNA gyrase
Only po treatment of pseudomonas
Arthralgias, achilles heel rupture, peripheral neuropathy
Bacteriostatic: used mainly for prophylactic UTI
Can be used for ESBL-producing Gram negative rods
Can only use for treatment of cystitis, not a pyelonephritis
irrelevant penetration outside of urine
Gram + organisms
drug of choice for VRE, PO option for clinda-resistant MRSA
Liver toxicity, thrombocytopenia, peripheral neuropathy
Resistant gram + organisms, including for SSTI, endocarditis due to MRSA
Once-daily dosing
**elevated CPK
**caution with tobramycin, anticoagulant treatment
no activity in lung tissue, do not use for penumonia
Cryptosporidium parvum and Giardia lamblia
in vitro/ in vivo against C. difficile
3 day treatment
**GI upset main SE
Approved in children!
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