Determining the optimal antibiotic duration for skin and soft tissue infections.

PURPOSE OF REVIEW

Optimal duration of therapy in SSTIs - a heterogeneous group of infections - remains unknown. The advances in knowledge of antibiotic duration of treatment in selected SSTIs that can impact clinical practice and published in the last 18 months are reviewed.

RECENT FINDINGS

Recent evidence indicates that few patients receive guideline concordant empiric antibiotics and appropriate duration in the United States, although this likely can be extrapolated to other countries. One of the most commonly identified opportunities to improve antibiotic stewardship is duration of therapy more than 10 days. The long-standing debate regarding the significance of abscess size and its impact on clinical response to antibiotics, following proper drainage, is increasingly shifting towards the conclusion that abscess size is not directly associated with cure.In obese patients with SSTI, there is no benefit to longer antibiotic durations for SSTIs in patients with obesity, and it appears that longer antibiotic duration of therapy was associated with increased treatment failure. In diabetic foot infections (DFO), two randomized studies suggest that in the presence of osteomyelitis, the total duration of antibiotic therapy for patients treated nonsurgically does not need to be more than 6 weeks. In a prospective, randomized, noninferiority, pilot trial, patients with DFO who underwent surgical debridement and received either a 3-week or 6-week course of antibiotic therapy had similar outcomes and antibiotic-related adverse events. In patients with necrotizing soft tissue infections, successive observational studies clearly suggest that short duration of antibiotic treatment after NSTI source control is as well tolerated and effective as a longer course. It appears that 48 h would be enough. The possibility of fixed versus individualized approaches to therapy for common bacterial infections, including SSTIs merits to be considered seriously. Fully individualized therapy may be an ideal approach to maximize the benefits and minimize the harms of antimicrobials. Much more work is needed before this strategy becomes feasible.

SUMMARY

There is increasing evidence that shorter duration of treatment is better in different types of SSTIs. Paradoxically, evaluation of real-life clinical practice indicates that long treatments continue to be commonly given to this population.