Carbapenems (kursiv)

• Imipenem is always given with cilastatin, which inhibits human dehydropeptidase I (a renal tubular enzyme that breaks down imipenem).

• Meropenem is stable to dehydropeptidase I.

• Last-resort drugs (used only in life-threatening infections or after other antibiotics have failed) because of the significant adverse effects

• Broad-spectrum antibiotics with intrinsic beta-lactamase resistance

  • Gram-positive cocci (except for MRSA and Enterococcus faecalis and Enterococcus faecium, which are intrinsically resistant)

  • Gram-negative rods, including Pseudomonas aeruginosa (except ertapenem which has limited activity against Pseudomonas)

  • Anaerobes

• Secondary fungal infections

• CNS toxicity: can lower seizure threshold at high serum concentrations

  • Highest risk: imipenem

  • Lowest risk: meropenem

• Gastrointestinal upset

• Rash

• Thrombophlebitis

inactivation by carbapenemase

• A type of β-lactamase

• Produced by carbapenemase-producing Enterobacteriaceae (e.g., E. coli, K. pneumoniae, K. aerogenes)