Alan M. Tennenberg

High-dose, short-course levofloxacin for community-acquired pneumonia: a new treatment paradigm.

Levofloxacin demonstrates concentration-dependent bactericidal activity most closely related to the pharmacodynamic parameters of the ratio of area under the concentration-time curve (AUC) to minimum inhibitory concentration (MIC) and the ratio of peak plasma concentration (C(max)) to MIC. Increasing the dose of levofloxacin to 750 mg exploits these parameters by increasing peak drug concentrations, allowing for a shorter course of treatment without diminishing therapeutic benefit. This was demonstrated in a multicenter, randomized, double-blind investigation that compared levofloxacin dosages of 750 mg per day for 5 days with 500 mg per day for 10 days for the treatment of mild to severe community-acquired pneumonia (CAP). In the clinically evaluable population, the clinical success rates were 92.4% (183 of 198 persons) for the 750-mg group and 91.1% (175 of 192 persons) for the 500-mg group (95% confidence interval, -7.0 to 4.4). Microbiologic eradication rates were 93.2% and 92.4% in the 750-mg and 500-mg groups, respectively. These data demonstrate that 750 mg of levofloxacin per day for 5 days is at least as effective as 500 mg per day for 10 days for treatment of mild-to-severe CAP.

Levofloxacin compared with imipenem/cilastatin followed by ciprofloxacin in adult patients with nosocomial pneumonia: a multicenter, prospective, randomized, open-label study.

BACKGROUND Therapy of nosocomial pneumonia is usually empiric and includes > or = 1 broad-spectrum antimicrobial agent. When considering the use of fluoroquinolones in these difficult-to-treat infections--in which drug delivery to the site of infection may be impaired or organisms with higher minimum inhibitory concentrations may be present--an agent should be chosen whose pharmacodynamics ensure maximal drug exposure. Use of the 750-mg dose of levofloxacin should enhance therapeutic benefit in patients with nosocomial pneumonia. OBJECTIVE The goal of this study was to compare the efficacy and safety of levofloxacin 750 mg and imipenem/cilastatin followed by ciprofloxacin in adult patients with nosocomial pneumonia. METHODS This was a multicenter, prospective, randomized, open-label trial conducted in North America. Patients were randomly assigned to 1 of 2 treatment arms: levofloxacin 750 mg QD given i.v. and then orally for 7 to 15 days or imipenem/cilastatin 500 mg to 1 g i.v. every 6 to 8 hours, followed by oral ciprofloxacin 750 mg every 12 hours for 7 to 15 days. Adjunctive antibacterial therapy was mandatory in patients with documented or suspected Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus infection. The primary predefined outcome measure was the clinical response (cure, improvement, failure, or unable to evaluate) in microbiologically evaluable patients 3 to 15 days after the end of therapy. RESULTS The study enrolled 438 adult patients (315 men, 123 women; mean [SD] age, 55.7 [20.04] years). Two hundred twenty patients received levofloxacin, and 218 received the comparator regimen. Demographic and baseline clinical characteristics were similar in the intent-to-treat and clinically evaluable populations. In patients evaluable for microbiologic efficacy, clinical success (cure or improvement) was achieved in 58.1% (54/93) of patients who received levofloxacin, compared with 60.6% (57/94) of patients who received the comparator regimen (95% CI, -12.0 to 17.2). Similar clinical results were seen in patients evaluable for clinical efficacy and in the intent-to-treat population. In the 187 patients evaluable for microbiologic efficacy, eradication was achieved in 66.7% (62/93) of patients receiving levofloxacin and 60.6% (57/94) of patients receiving the comparator regimen (95% CI, -20.3 to 8.3). CONCLUSION In this study, levofloxacin was at least as effective and was as well tolerated as imipenem/cilastatin followed by ciprofloxacin in adult patients with nosocomial pneumonia, as demonstrated by comparable clinical and microbiologic success rates.

A Multicenter, Open-Label, Randomized Comparison of Levofloxacin and Azithromycin Plus Ceftriaxone in Hospitalized Adults with Moderate to Severe Community-Acquired Pneumonia

BACKGROUND Changing etiologic patterns and the growing problem of antimicrobial resistance, particularly an increase in macrolide-resistant pneumococcal bacteremia, are causing physicians to adopt new approaches to the treatment of community-acquired pneumonia (CAP). OBJECTIVE The relative efficacy and tolerability of levofloxacin monotherapy and azithromycin and ceftriaxone combination therapy were assessed in hospitalized adults with moderate to severe CAP. METHODS This Phase IV, multicenter, open-label, randomized trial compared 2 treatment regimens: (1) levofloxacin 500 mg PO or IV q24h, and (2) azithromycin 500 mg IV q24h for > or = 2 days plus ceftriaxone 1 g IV q24h for 2 days, followed by an optional transition to azithromycin 500 mg PO q24h at the investigators discretion. The total duration of therapy was to be a minimum of 10 days in both treatment groups. Ceftriaxone was included in the initial azithromycin regimen to ensure coverage against pneumococcal bacteremia. RESULTS Of 236 patients in the intent-to-treat population, completion or withdrawal information was available for 110 patients in the levofloxacin group and 114 in the azithromycin group. Baseline demographic and disease characteristics were comparable between groups. At the end of treatment, the clinical success rate (cured + improved) in clinically evaluable patients was 94.1% in the levofloxacin group and 92.3% in the azithromycin group. The respective posttherapy microbiologic eradication rates were 89.5% and 92.3%. Levofloxacin was as well tolerated as azithromycin, with an incidence of drug-related adverse events (AEs) for all body systems of 5.3% and 9.3%, respectively. None of the drug-related AEs were considered serious [corrected]. CONCLUSIONS In this study in hospitalized patients with moderate to severe CAP, levofloxacin monotherapy was at least as effective as a combination regimen of azithromycin and ceftriaxone in providing coverage against the current causative pathogens in CAP. In addition, levofloxacin was as well tolerated as the combination of azithromycin and ceftriaxone.

Efficacy of 750-mg, 5-day levofloxacin in the treatment of community-acquired pneumonia caused by atypical pathogens

SUMMARY Background: Current recommended durations for treatment of atypical community-acquired pneumonia (CAP) range from 10 to 21 days. However, antibiotics such as the fluoroquinolones may allow for effective, short-course regimens. Objective: This study evaluated the efficacy of 750 mg levofloxacin for 5 days compared to a 500-mg, 10-day levofloxacin regimen for the treatment of atypical CAP. Methods: A randomized, active-controlled, double-blind, multicenter study was conducted within the United States. Of the 528 patients enrolled in the study, 149 were diagnosed with CAP due to Legionella pneumophila, Chlamydia pneumoniae, or Mycoplasma pneumoniae. Patients’ baseline symptoms were re-evaluated on Day 3 of therapy. Clinical efficacy and resolution of CAP symptoms were evaluated at the posttherapy visit (7–14 days after the last dose of active drug). Results: This report represents a subgroup analysis of a previous clinical study. Among the 123 clinically evaluable patients diagnosed with atypical CAP (26 patients were unevaluable), the clinical success rates were 95.5% (63 of 66 patients) for the 750-mg group and 96.5% (55 of 57 patients) for the 500-mg group (95% CI for success rate of the 500-mg group minus that of the 750-mg group, –6.8 to 8.8). At the poststudy evaluation (31–38 days after treatment began), relapse occurred in ≤ 2% of patients in either treatment group. Among patients diagnosed with atypical CAP, the 750-mg therapy resulted in more rapid symptom resolution, with a significantly greater proportion of patients experiencing resolution of fever by Day 3 of therapy ( p = 0.031). Conclusion: The 750-mg, 5-day course of levofloxacin was at least as effective as the 500-mg, 10-day regimen for atypical CAP. Additionally, the 750-mg, short-course levofloxacin therapy may reduce total antimicrobial drug usage and more rapidly relieve pneumonia symptoms.

A multicenter, randomized, double-blind, retrospective comparison of 5- and 10-day regimens of levofloxacin in a subgroup of patients aged ≥65 years with community-acquired pneumonia

OBJECTIVE This subgroup analysis sought to determine the efficacy and tolerability of a 5-day regimen of levofloxacin 750 mg/d compared with a 10-day regimen of levofloxacin 500 mg/d in the treatment of community-acquired pneumonia (CAP) in elderly patients (aged > or =65 years). METHODS This subgroup analysis was based on the outcomes in patients aged > or =65 years from a randomized, double-blind, controlled trial conducted at 70 US centers. Patients in Pneumonia Severity Index (PSI) class I/II and III/IV were randomized to receive levofloxacin 750 mg/d for 5 days or levofloxacin 500 mg/d for 10 days. Study investigators assessed clinical and microbiologic outcomes 7 to 14 days after administration of the last dose of medication and collected adverse events for 30 days after the last dose. RESULTS This analysis included 177 elderly patients, 80 receiving levofloxacin 750 mg/d for 5 days and 97 receiving levofloxacin 500 mg/d for 10 days. Although most demographic and baseline clinical characteristics were comparable between the 2 groups, the group that received levofloxacin 500 mg/d was older than the group that received levofloxacin 750 mg/d (median age, 76.0 vs 72.5 years, respectively; P = 0.029) and had a higher mean PSI score (90.7 vs 83.1; P = 0.017). Despite the halved duration of therapy, unadjusted clinical success rates were comparable between the 2 groups (89.0% and 91.9% in the 750- and 500-mg arms, respectively; 95% CI, -7.1 to 12.7). Microbiologic eradication rates were 90.3% (28/31) in the 750-mg arm and 87.5% (14/16) in the 500-mg arm (P = NS). Multivariate analysis adjusting for baseline PSI score indicated that treatment assignment was not statistically associated with clinical success (adjusted odds ratio for clinical success with 500-mg dose, 1.92; 95% CI, 0.62 to 5.99). The incidence of treatment-emergent adverse events did not differ between the 2 study treatments. The most common adverse events in both groups were insomnia, constipation, and headache. CONCLUSIONS This subgroup analysis found that levofloxacin 750 mg/d for 5 days was well tolerated in the treatment of CAP in elderly patients. Undajusted and adjusted rates of clinical success were statistically similar between levofloxacin 750 mg/d for 5 days and levofloxacin 500 mg/d for 10 days.

Levofloxacin for Treatment of Ventilator-Associated Pneumonia: A Subgroup Analysis from a Randomized Trial

Ventilator-associated pneumonia (VAP) remains a significant challenge in critical care. We conducted a secondary analysis of a multicenter, prospective, randomized trial comparing levofloxacin (750 mg iv q24h) with imipenem-cilastatin (500-1000 mg iv q6-8h) for treatment of nosocomial pneumonia and focused on the subgroup of patients with VAP. The study cohort included 222 patients, with half (111) of the patients assigned to each treatment group. The patients in both groups were similar with respect to age, severity of illness, and duration of mechanical ventilation before the onset of VAP. Among the intention-to-treat population, clinical success was achieved in 58.6% of patients receiving levofloxacin, compared with 63.1% of patients receiving imipenem-cilastatin (P=.49; 95% confidence interval for the difference, -8.77% to 17.79%). Microbiological success and 28-day mortality rates were also comparable. Multivariate analysis demonstrated that assignment to antibiotic treatment (i.e., levofloxacin vs. imipenem-cilastatin) was not predictive of outcomes, thus suggesting that the treatment regimens were equivalent. Both levofloxacin and imipenem-cilastatin regimens were well tolerated and had similar adverse event profiles.

Clinical implications of 750 mg, 5-day levofloxacin for the treatment of community- acquired pneumonia *

SUMMARY Objective: To evaluate the time to symptom resolution and IV-to-PO transition in community-acquired pneumonia (CAP) patients treated with 750 mg or 500 mg levofloxacin. Research Design: A retrospective, subset analysis of a multicenter, randomized, double-blind, controlled trial comparing 750 mg levofloxacin for 5 days to 500 mg levofloxacin for 10 days for the treatment of CAP. Patients and Methods: A total of 528 CAP patients were included. Baseline symptoms were re-evaluated on Day 3 of therapy, and time to IV-to-PO transition was recorded for inpatients. Results: For the overall population, 67.4% of patients receiving 750 mg levofloxacin had resolution of fever by Day 3 of therapy, compared to 54.6% of 500 mg treated patients ( P = 0.006). Patients who started on 750 mg levofloxacin IV ( N = 108) transitioned to PO in an average of 2.68 days while those starting on 500 mg IV ( N = 124) transitioned in 2.95 days ( P = 0.144). The median time for IV-to-PO switch was 2.35 days and 2.75 days for patients receiving 750 mg and 500 mg levofloxacin, respectively ( P = 0.098, log rank test). By Day 3 of therapy, 68% of patients receiving the 750 mg dose had transitioned from IV to PO levofloxacin, compared with 61% of the 500 mg group ( P = 0.280). The safety profiles were comparable for the two regimens. Conclusions: The 750 mg levofloxacin dose resulted in a greater proportion of patients with resolution of CAP symptoms by Day 3 when compared with 500 mg therapy. Consequently, the 750 mg regimen trended toward more rapid transition to PO, potentially resulting in lower overall drug costs. Time to switch from IV to PO was determined by the investigators’ discretion rather than a set protocol. Additionally, length of stay data was not collected in this study, which can significantly impact overall healthcare costs. Further research is required to fully understand the economic impact of the 750 mg, 5-day levofloxacin regimen.

Pneumonia due to Pseudomonas aeruginosa:the levofloxacin clinical trials experience

ABSTRACT Respiratory infections caused by Pseudomonas aeruginosa present significant treatment challenges, including that of overcoming intrinsic and adaptive resistance by these organisms. The fluoroquinolones may provide an effective option for treating these infections. In this analysis, we report on the efficacy of levofloxacin in the treatment of community-acquired pneumonia (CAP) and nosocomial pneumonia caused by P. aeruginosa using information from nine clinical studies supported by Johnson & Johnson Pharmaceutical Research and Development (Raritan, NJ) or Ortho-McNeil Pharmaceutical (Raritan, NJ). From these studies, a total of 36 patients were identified with pneumonia caused by P. aeruginosa and treated with levofloxacin (750 mg or 500 mg). For patients diagnosed with nosocomial pneumonia, levofloxacin treatment achieved a 64.7% (11/17) clinical success rate, compared with 41.2% (7/17) with comparator treatment (imipenem/cilastatin followed by ciprofloxacin) in the microbiologically evaluable population. Eradication rates were 58.8% with levofloxacin treatment vs. 29.4% with comparator (95% CI, -64.2 to 5.4). For levofloxacin-treated CAP patients with P. aeruginosa infections (n = 19), clinical success and microbiological eradication rates in the microbiologically evaluable population were 89.5% and 78.9%, respectively. Several limitations of this analysis exist including that this was a retrospective evaluation that pooled data from multiple studies with varying protocols, the number of patients included was limited, and the nosocomial pneumonia patients used adjunctive therapy with an antipseudomonal β-lactam in most cases. Nonetheless, these findings suggest that levofloxacin may play a role in the treatment of these difficult respiratory infections.