What they are

• Meropenem
• Imipenem-Cilastatin
  • Cilastin/cilastatin: Renal dihydropeptidase inhibitor (stops Imipenem degradation)
• Ertapenem
  • Once daily
• Doripenem
  • Not approved for treating LRTI
  • Cf imipenem/cilastatin: less cure, more mortality
  • TID dosing
• Imipenem-Cilastatin-Relebactam
  • I/C + Class A/C beta-lactamase inhibitor
• Meropenem-Vaborbactam
  • Vaborbactam inhibits KPC carbapenemases → used for KPC organisms.

http://www.microbiologynutsandbolts.co.uk/the-bug-blog/new-sweets-on-the-market-but-will-these-new-flavours-live-up-to-their-vibrant-colours

Spectrum

Easier what they don’t cover

• Intrinsic resistance
  • All carbapenems: (Stay alert Elizabeth)
    • Stenotrophomonas maltophilia
    • Aeromonas spp
    • Elizabethkingia meningoseptica
    • Bacillus cereus
  • Serratia and protea – imipenem R
  • Not great Enterococcus cover
  • No cell wall:
    • Chlamydophila pneumoniae
    • Chlamydophila psittaci
    • Coxiella burnetii
    • Mycoplasma pneumonia
  • No cover of ertAPEnem: Acinetobacter, Pseudomonas, Enterococci
• Acquired resistance
  • Carbapenemases – will discuss next episode, e.g. KPC, NDMs, various OXAs
  • Other non-carbapenemase betalactamases + porin loss e.g. AmpC or ESBL
  • Pseudomonas mechanisms:
    • Upregulated effux – Mero R
    • OprD porin loss – Imipenem R

How to use them

• On advice of ID/Micro