The purpose of this review is to assess the relative strengths and weaknesses of individual members of the
carbapenem class of
antibiotics. Clinical trials and review articles were identified from a Medline search (1979 - July 2006), in addition to, reference citations from identified publications, abstracts from the Interscience Conferences on
Antimicrobial Agents and
Chemotherapy and the 12th International Congress on
Infectious Disease, and package inserts. Articles in English were reviewed, with emphasis on those containing efficacy or safety data.
Carbapenems bind to critical
penicillin-binding proteins, disrupting the growth and structural integrity of bacterial cell walls. They provide enhanced anaerobic and Gram-negative coverage as compared with other
beta-lactams and their stability against extended-spectrum
beta-lactamases (ESBLs) makes them an effective treatment option. The most common adverse effects are infusion-site complications and gastrointestinal distress.
Ertapenem has limited efficacy against non-fermenting, Gram-negative bacteria, restricting its use to
community-acquired infections.
Imipenem is slightly more effective against Gram-positive organisms and
meropenem slightly more effective against Gram-negative organisms. However, both have broad-spectrum activity, including non-fermenting, Gram-negative bacteria. Among non-fermenting, Gram-negatives, resistance to
imipenem in particular is increasing.
Doripenem is in late-stage clinical development and combines the broad-spectrum coverage of
imipenem and
meropenem, and more potent activity against Pseudomonas aeruginosa. Due to the increasing challenges represented by ESBLs and multi-
drug resistant organisms, the
carbapenems are assuming a greater role in the treatment of serious
infections.
Imipenem and
meropenem are presently available and have been shown to be effective against
nosocomial infections.
Doripenem is an investigational
carbapenem that has completed Phase III clinical trials and that has the potential to improve on this efficacy and minimize the emergence of resistance to the
carbapenem class.