Short-Duration Therapy for Respiratory Tract Infections

Modeling antibiotic resistance in hospitals: the impact of minimizing treatment duration

Infections caused by antibiotic-resistant pathogens are a global public health problem. Numerous individual- and population-level factors contribute to the emergence and spread of these pathogens. An individual-based model (IBM), formulated as a system of stochastically determined events, was developed to describe the complexities of the transmission dynamics of antibiotic-resistant bacteria. To simplify the interpretation and application of the model's conclusions, a corresponding deterministic model was created, which describes the average behavior of the IBM over a large number of simulations. The integration of these two model systems provides a quantitative analysis of the emergence and spread of antibiotic-resistant bacteria, and demonstrates that early initiation of treatment and minimization of its duration mitigates antibiotic resistance epidemics in hospitals.

How long should we treat community-acquired pneumonia?

PURPOSE OF REVIEW

The studies reviewed in this article suggest that a shorter duration of antibiotic therapy is comparable to standard therapy in the treatment of community-acquired pneumonia and promotes reduction of adverse events, microbial resistance, cost, and improved patient compliance.

RECENT FINDINGS

Community-acquired pneumonia has traditionally been treated with a 7-14-day course of antimicrobial therapy. Since there have been few well controlled trials regarding the optimal duration of therapy, however, there has been no consensus on length of therapy among different organizational guidelines. Several recent studies have demonstrated that shorter course antibiotic regimens are effective in the treatment of community-acquired pneumonia.

SUMMARY

Short-course antibiotic therapy is equivalent to standard length of therapy for clinical cure and bacterial eradication. Minimization of drug exposure, however, reduces selection pressure for resistant strains, strengthens patient compliance, and potentially reduces adverse events such as Clostridium difficile infections.

Gemifloxacin once daily for 5 days versus 7 days for the treatment of community-acquired pneumonia: a randomized, multicentre, double-blind study

OBJECTIVES

Short-course therapy has been advocated for the treatment of community-acquired pneumonia (CAP). We compared the efficacy and safety of 5 and 7 day courses of gemifloxacin for outpatient treatment of mild-moderate CAP.

PATIENTS AND METHODS

In a multicentre, double-blind, parallel group study, patients were randomized to receive 320 mg of oral gemifloxacin once daily for 5 or 7 days. Over 95% of all patients in each cohort had a Fine score of <or=III. The primary efficacy endpoint was clinical cure at follow-up (days 24-30). Secondary outcomes were clinical and bacteriological responses at the end of therapy (days 7-9) and bacteriological and radiological responses at follow-up. Adverse events (AEs) were also monitored.

RESULTS

In a total of 469 per protocol (PP) patients, clinical resolution at follow-up was 95% and 92% for 5 and 7 day treatments, respectively [95% confidence interval (CI) -1.48, 7.42], indicating non-inferiority of 5 day treatment. Clinical resolution at the end of therapy was 96% for both regimens (95% CI -3.85, 3.42). Bacteriological response rates in PP patients at the end of therapy were 94% and 96% for 5 and 7 day groups, respectively (95% CI -8.27, 3.25) and 91% for both groups at follow-up (95% CI -6.89, 7.93). Radiological success in PP patients at follow-up was 98% and 93% in 5 and 7 day groups, respectively (95% CI 0.35, 7.91). Pre-therapy pathogens were identified in 242 (47.3%) patients, most commonly Streptococcus pneumoniae. Frequency of treatment-related AEs was 21% in both cohorts with discontinuation rates of 1.2% and 2% in the 5 and 7 day groups, respectively. A lower incidence of rash was observed in the 5 day cohort (0.4%) versus the 7 day cohort (2.8%) (P=0.04).

CONCLUSIONS

Gemifloxacin once daily for 5 days is not inferior to 7 days in the PP population with respect to clinical, bacteriological and radiological efficacy. Further work is needed, however, to explore whether fewer treatment days would improve patient compliance and reduce the incidence of AEs.