[Antimicrobial combination therapy]

Abstract

Anti-microbial combination therapy is a very frequently used therapeutic approach although clinical data from prospective randomized trials thus fulfilling the criteria of evidence based medicine are very rare. Rationales for the use of combination therapy are thus empirical treatment of polymicrobial infections, infections in critical ill or in immuno-compromised patients, prevention of the emerge of antibiotic resistances, utilization of a potential synergism of antibiotics directed against a certain bacterial strain, or simply despair. Prospective studies have demonstrated a superiority of combination therapy over single drug regimen in enterococcal endocarditis, and infections with gram negative rods including pseudomonas sp., but in the latter condition only if the patient is severely immuno-compromised. There is clinical indication that combination therapy may be beneficial in infections with staphylococci sp., however, well designed studies supporting this experience are largely absent. Nonetheless, antimicrobial combination therapy also harbors some risks for patients which can be referred to potential antagonism between antibiotics, accumulation of side effects, or stimulation of resistance pathways in bacteria by one drug leading to destabilization of the other one. Thus, the insightful use of combination therapy is warranted and well designed, prospective studies are urgently needed to evaluate the true benefit of combination therapy for the treatment of different infections and specific micro-organisms.