Carbapenems.

Carbapenems are broad-spectrum beta-lactam antibiotics that cover an absolute majority of all bacterial pathogens that possess a cell wall. The only clinically important exceptions are X. maltophilia, E. faecium, and some strains of methicillin-resistant staphylococci and penicillin-resistant pneumococci. So far, after several years of clinical use of imipenemcilastatin, emergence of resistance has been a problem mainly restricted to P. aeruginosa. The pharmacokinetics of carbapenems, especially imipenem, are complicated by the renal metabolism, necessitating the imipenem-cilastatin combination. This is not required for meropenem. The safety profile of carbapenems is favorable. With imipenem-cilastatin, nausea constitutes a practical problem in that administration times may have to be prolonged. The risk for neurologic reactions with imipenem-cilastatin has become a factor reducing the possibilities to use high doses. For all indications except bacterial meningitis, the now approved maximal dose of 4 g per day should suffice. In this respect, meropenem has an advantage over imipenem-cilastatin in that it can be used in the treatment of bacterial meningitis without apparent increased risk of seizures. Carbapenems are indicated mainly as empiric monotherapy in serious infections, such as intra-abdominal infections and infections in neutropenic patients. Combinations of carbapenems and other antibiotics should not be used routinely.