Efficacy of antimicrobial agent treatment in relation to treatment regimen: experimental models and clinical evaluation.

The effect of the duration of treatment on clinical and bacteriological efficacy is generally poorly evaluated for antimicrobial agents. Infection model studies have to a large extent concentrated on endocarditis. In clinical trials systematic and well controlled studies are abundant in the field of urinary tract infections and streptococcal tonsillopharyngitis, but almost non-existent in other types of infections. Paradoxically, most of the infections studied by experimental models are uncommon in man and evaluation of optimal treatment periods for these by clinical trial is therefore difficult. In the evaluation of new antimicrobial agents, closer collaboration of experimental model and clinical trial investigators is required to design models of infections and clinical trials to evaluate optimal duration of treatment.