[A comparative review of combination therapy: 2 beta-lactams versus beta-lactam plus aminoglycoside]

We have reviewed the available literature on the controlled use of combinations of beta-lactams in the treatment of fever in neutropenic patients, as compared to that of combinations of beta-lactams and aminoglycosides. We compared overall responses, responses in septicemia and various other infections, according to different pathogens and degree of neutropenia, and we evaluated toxicity. Overall, these results showed that response rates with combinations of two beta-lactams are similar to those obtained with combinations of a beta-lactam and an aminoglycoside for infections in immunocompromised patients with serious underlying diseases. They also suggest that the emergence of resistance of pathogens to beta-lactams has often been coped by the use of newer drugs in infections caused by Enterobacteriaceae, but much less effectively in the case of Pseudomonas aeruginosa infections. There are still other important theoretical reasons for preferring an aminoglycoside-containing combination for empiric therapy in febrile neutropenic patients, and our overall conclusion is that a large-scale study comparing beta-lactam combinations to the traditional beta-lactam plus aminoglycoside regimens is mandatory.