Cell Wall Active Antibiotics Flashcards
Beta-Lactams
Penicillins, Cephalosporins, Monobactams, Carbapenems, BL-inhibitor combinations
MOA: Inhibition of transpeptidases (penicillin-binding proteins [PBPs])
ADR: Hypersensitivity, Diarrhea (due to C.diff), Neutropenia, thrombocytopenia, hemolytic anemia.
Rare: Neurotoxicity (seizures, myoclonic jerking, twitching, confusion)
Pearls: All can potentially cause hypersensitivity (rash to anaphylaxis). All have potential to cause seizures (high dosing or wrong renal dose adjustment)
Natural Penicillins
β-lactam
Penicillin VK: 250-500mg PO q6-8
Coverage:
Gram (+): Streptococci (S. pneumoniae, S. pyrogenes), Enterococci
Gram (-): N. meningitis
Spirochetes: Treponema pallidum (Syphilis) [DOC]
Anaerobes: mouth anaerobe flora
Uses: susceptible organisms and PKPD permitting sites of infection (narrow spectrum)
Anti-staphylococcal Penicillins
β-lactam
Nafcillin 1-2g IV q4-6h
Oxacillin 1-2g IV q4-6h
Dicloxacillin PO
Coverage:
Gram (+): Natural PCN coverage with improved MSSA activity
Uses: MSSA (methicillin-sensitive S. aureus)
ADR: Higher risk of acute interstitial nephritis (AIN)
Nafcillin: thrombophlebitis and sodium load in cHF
Do NOT require renal dose adjustment.
Aminopenicillins
β-lactam
Ampicillin IV
Amoxicillin 250-500mg PO q8h
Gram (-): Nautral PCN coverage with improved Enterococcus activity
Gram (-): H. influenzae, E.coli, Proteus, Klebsiella (PEK) Salmonella, Shigella
Uses: susceptible organisms, meningitis, sinusitis, otitis media, E. faecalis (+-) gentamicin
Penicillin BLIC (beta lactamase inhibitor combinations)
β-lactam
Augmentin (Amoxicilin-Clavulanic acid)
Unasyn (Ampicillin-Sulbactam)
Zosyn (Pipercillin-Tazobactam): 2.25-4.5g IV q6h
Coverage:
G(+): MSSA, Streptococci
G(-): broad spectrum, Enterobacteriaceae, H. influenzae, Moraxella, Anaerobes
Pseudomonas Aeruginosa coverage: Zosyn and Augmentin
ADR: sodium load in CHF (Ticarcillin, Piperacillin, Nafcillin)
1st Gen Cephalosporin
β-lactam
Cephalexin (Keflex): 250-500mg PO q6h
Cefazolin 1-2g IV q8h
Coverage:
G(+): MSSA, Streptococci
G(-): Proteus, E. coli, Klebsiella (PEK), resistance emerging
Uses: soft/skin tissue infection, surgical prophylaxis
2nd Gen Cephalosporin
β-lactam
Cefuroxime
Cefoxitin
Cefotetan
Coverage:
G(+): similar to 1st gen
Gram(-): PEK + (H.influenzae, Enterobacter, Nisseria)
HEN Anaerobes: Bacteroides (cefotetan, cefoxitin)
Uses: upper respiratory infections, skin/soft tissue, surgical prophylaxis
3rd Gen Cephalosporin
β-lactam
extended spectrum
Ceftazidime
Cefdinir
Cefixime
Ceftriaxone (Rocephin): 1-2g IV q12-24h
Coverage:
G(+): compared to 1st gen
↓ MSSA, ↑ Streptoccus
G(-): HEN, PEK + Citrobacter, Salmonella, Shigella, Serratia
Pseudomonas: Ceftazidime
Uses: Community and hospital acquired infections, meningitis
4th Gen Cephalosporin
β-lactam
extended specturm
Cefepime (Maxipime): 1-2g IV q8-12h
Coverage:
G(+): MSSA, Streptococci
G(-): 3rd generation + Pseudomonas
Uses: broad spectrum, empiric therapy for many hospital acquired infections
5th Gen Cephalosporin
β-lactam
extended spectrum
Ceftaroline (Teflaro)
Coverage:
G(+): Streptococcus, MRSA
G(-): some coverage (lost pseudomonas), Citrobacter
Uses: MRSA pneumonia, mixed MRSA skin/soft tissue
Cephalosporin BLIC (beta lactamase inhibitor combination)
β-latam
extended spectrum
Zerbaxa (Ceftolozane-Tazobactam)
Avycaz (Ceftazidime-Avibactam
Zerbaxa: target MDRO (KPCs)
Siderophores
Cefiderocol (Fetroja, IV)
β-lactam
extended spectrum
Designed to have activity against MDR Pseudomonas and A. baumannii
Cephalosporin ADR/Pearls
ADR: Hypersensitivity (cross-sensitivity with penicillins is low [later generations < early generations]) If IgG/M reaction to PCN, can give cephalosporin with caution. If IgE anaphylaxis do NOT give cephalosporin)
GI: N/V, abdominal pain, potential C. diff
Ceftriaxone: biliary sludging in neonates, not recommended in neonates (<28 days)
Most have 1-4 hours half life, except Ceftriaxone (8h) can give 24h dosing
Monobactams
β-lactam
Aztreonam IV
Coverage:
G(-): Enterobacteriaceae, Pseudomonas
Uses: UTI, pneumonia, bacteremia, PCN-allergic patients
ADR: little to no cross-sensitivity to other BLs except Ceftazidime
Carbapenems
β-lactam
Broad spectrum of activity
Imipenem-cilastatin
Ertapenem
Meropenem
Doripenem
Mero-Vaborbactam (Vabomere) used for CRE (carbapenem-resistant Enterococcus)
Imipenem-Cilstatin-Relebactam (Recarbrio) used for CRE
Coverage:
G(+): Staphylococci, Streptococci, Enterococci (not VRE)
G(-): Enterobacteriaceae, Pseudomonas and A. baumannii (except Ertapenem)
Anaerobic: B. fragilis, above diaphragm anaerobes
Uses: polymicrobial infections, identified/suspected ESBL producers, used empirically for severe infections.
ADR: Imipenem can cause seizures at very high doses or wrong renal adjustments
Pearls: Imipenem is inactivated by dehydropeptidase I enzyme in the kidneys (can lead to nephrotoxic metabolites). Cilastatin inhibits the enzyme (utilized with Imipenem)
