Pharmacokinetics, Safety, and Tolerability of Single-Dose Intravenous Moxifloxacin in Pediatric Patients: Dose Optimization in a Phase 1 Study

The pharmacokinetics, safety, and tolerability of a single dose of moxifloxacin were characterized in 31 pediatric patients already receiving antibiotics for a suspected or proven infection in an open-label phase 1 study. A dosing strategy for each age cohort (Cohort 1: ≥6 years to ≤14 years; Cohort 2: ≥2 years to <6 years; Cohort 3: >3 month to <2 years) was developed using physiology-based pharmacokinetic modeling combined with a stepwise dosing scheme to obtain a similar exposure to adults receiving 400 mg of moxifloxacin. Doses, adjusted to body weight and age, were gradually escalated from 5 mg/kg in Cohort 1 to 10 mg/kg in Cohort 3 based on interim analysis of the pharmacokinetic and safety data. Plasma and urine samples before and after the 60-minute infusion were collected for the analysis of moxifloxacin and its metabolites using a validated high-pressure liquid chromatography assay with tandem mass spectrometry. Moxifloxacin and metabolite concentrations in plasma were within the ranges observed in adults; however, clearance of all analytes was lower in pediatric patients compared with adults. Population pharmacokinetic analyses using the achieved exposure levels in the 3 age cohorts (with known body weight and clearance) predicted similar efficacy and safety profiles to adults. Moxifloxacin was well tolerated in all pediatric age cohorts. Adverse events related to moxifloxacin were mild or moderate in intensity and showed no correlation with increased weight-adjusted doses. Our findings guided the selection of age-appropriate clinical doses for a subsequent phase 3 clinical trial in pediatric patients with complicated intra-abdominal infections.

Moxifloxacin in Pediatric Patients With Complicated Intra-abdominal Infections: Results of the MOXIPEDIA Randomized Controlled Study

BACKGROUND

This study was designed to evaluate primarily the safety and also the efficacy of moxifloxacin (MXF) in children with complicated intra-abdominal infections (cIAIs).

METHODS

In this multicenter, randomized, double-blind, controlled study, 451 pediatric patients aged 3 months to 17 years with cIAIs were treated with intravenous/oral MXF (N = 301) or comparator (COMP, intravenous ertapenem followed by oral amoxicillin/clavulanate; N = 150) for 5 to 14 days. Doses of MXF were selected based on the results of a Phase 1 study in pediatric patients (NCT01049022). The primary endpoint was safety, with particular focus on cardiac and musculoskeletal safety; clinical and bacteriologic efficacy at test of cure was also investigated.

RESULTS

The proportion of patients with adverse events (AEs) was comparable between the 2 treatment arms (MXF: 58.1% and COMP: 54.7%). The incidence of drug-related AEs was higher in the MXF arm than in the COMP arm (14.3% and 6.7%, respectively). No cases of QTc interval prolongation-related morbidity or mortality were observed. The proportion of patients with musculoskeletal AEs was comparable between treatment arms; no drug-related events were reported. Clinical cure rates were 84.6% and 95.5% in the MXF and COMP arms, respectively, in patients with confirmed pathogen(s) at baseline.

CONCLUSIONS

MXF treatment was well tolerated in children with cIAIs. However, a lower clinical cure rate was observed with MXF treatment compared with COMP. This study does not support a recommendation of MXF for children with cIAIs when alternative more efficacious antibiotics with better safety profile are available.

Unmet needs in the management of intra-abdominal infections

INTRODUCTION

Intra-abdominal infections remain a leading cause of death, morbidity and resource use in surgical wards and intensive care units. The growing complexity of their management has led to new paradigms and unresolved issues in anti-infective therapy described in the current review. Areas covered: We analyzed the literature, recent guidelines, and expert opinions published over the last decade. Expert commentary: Prospective randomized trials are difficult to perform and observational studies or database analyses should be encouraged. Epidemiologic and microbiologic reports should be promoted, especially in developing/resource-limited countries and in specific subpopulations such as children, older people and patients with underlying diseases. The diagnostic process, including imaging procedures, could be improved. The value of biomarkers for diagnosis, monitoring and discontinuation of therapy should be clarified and improved. New microbiologic techniques are needed to speed up the diagnostic process and to improve the adequacy of anti-infective therapy. Very little progress has been made in the detection of clinical failures. Many aspects of anti-infective management, both for bacteria and fungi, remain unresolved, such as the high inoculum, the type of microorganisms to be treated, the timing of therapy, the value of de-escalation, drug monitoring and duration of therapy. New antibiotics are expected.

Prediction of Pharmacokinetics and Penetration of Moxifloxacin in Human with Intra-Abdominal Infection Based on Extrapolated PBPK Model

The aim of this study is to develop a physiologically based pharmacokinetic (PBPK) model in intra-abdominal infected rats, and extrapolate it to human to predict moxifloxacin pharmacokinetics profiles in various tissues in intra-abdominal infected human. 12 male rats with intra-abdominal infections, induced by Escherichia coli, received a single dose of 40 mg/kg body weight of moxifloxacin. Blood plasma was collected at 5, 10, 20, 30, 60, 120, 240, 480, 1440 min after drug injection. A PBPK model was developed in rats and extrapolated to human using GastroPlus software. The predictions were assessed by comparing predictions and observations. In the plasma concentration versus time profile of moxifloxcinin rats, C_max was 11.151 µg/mL at 5 min after the intravenous injection and t_1/2 was 2.936 h. Plasma concentration and kinetics in human were predicted and compared with observed datas. Moxifloxacin penetrated and accumulated with high concentrations in redmarrow, lung, skin, heart, liver, kidney, spleen, muscle tissues in human with intra-abdominal infection. The predicted tissue to plasma concentration ratios in abdominal viscera were between 1.1 and 2.2. When rat plasma concentrations were known, extrapolation of a PBPK model was a method to predict drug pharmacokinetics and penetration in human. Moxifloxacin has a good penetration into liver, kidney, spleen, as well as other tissues in intra-abdominal infected human. Close monitoring are necessary when using moxifloxacin due to its high concentration distribution. This pathological model extrapolation may provide reference to the PK/PD study of antibacterial agents.

Efficacy and safety of moxifloxacin in hospitalized patients with secondary peritonitis: pooled analysis of four randomized phase III trials

BACKGROUND

Secondary peritonitis is an advanced form of complicated intra-abdominal infection (cIAI) requiring hospitalization, surgical source control, and empiric antibiotic therapy against causative aerobic and anaerobic bacteria.

METHODS

This pooled analysis of four prospective, active-controlled randomized clinical trials compared the efficacy and safety of moxifloxacin with that of comparator antibiotics in patients with confirmed secondary peritonitis. The primary efficacy endpoint was clinical success rate at test-of-cure (TOC) between day 10 and 45 post-therapy in the per-protocol (PP) population. Safety and clinical efficacy were assessed also in the intent-to-treat population (ITT). Bacteriological success was assessed at TOC in the microbiologically-valid population as a secondary efficacy endpoint.

RESULTS

Overall clinical success rates at TOC were 85.3% (431 of 505 patients) in the moxifloxacin and 88.4% (459 of 519 patients) in the comparator treatment groups (PP population, point estimate for the difference in success rates: -3.0%; 95% CI -7.06%, 1.05%), respectively. Similar clinical success rates between moxifloxacin and comparators were observed by anatomical site of infection, and ranged from 80.6% to 100% for moxifloxacin and from 71.4% to 96.6% for comparators, respectively. Bacteriologic success rates were similar with moxifloxacin (82.4%) and comparators (86.8%), respectively. The proportion of patients experiencing any treatment-emergent adverse events was slightly higher with moxifloxacin (67.3%) versus comparators (59.8%). Rates of drug-related adverse events (20.9% versus 20.0%) and deaths (4.3% versus 3.4%) were similar in moxifloxacin and comparator groups; none of the deaths were drug-related.

CONCLUSIONS

The data suggests that once-daily IV (or IV/PO) moxifloxacin has a comparable efficacy and safety profile to antibiotic regimens approved previously in the subgroup of patients with secondary peritonitis of mild-to-moderate severity.

Severe autogenously fecal peritonitis in Wistar rats with permanent bilateral carotid occlusion. Response to intra peritoneal moxifloxacin combined with dexamethasone

PURPOSE

To evaluate the treatment outcome of severe peritonitis in rats submitted to permanent bilateral carotid occlusion (PBCO).

METHODS

Sixteen Wistar rats (mean age of 8.5 months) with PBCO underwent autogenously fecal peritonitis, and were treated with moxifloxacin combined with dexamethasone, and followed-up for 45 days. Ten rats (mean age five months) without PBCO were used as a control group. The variables were expressed by their mean and standard error of the mean (SEM). p<0.05 was used for rejecting the null hypothesis. The study was approved by the Ethics Committee.

RESULTS

There was a significant increase (p=0.0002) in the mortality and morbidity in older rats that underwent PBCO (study group). However, even among the survival rats presenting with severe residual abscesses both in the abdomen and thorax cavities, they present an almost normal life.

CONCLUSIONS

The treatment of severe autogenously fecal peritonitis with intraperitoneal moxifloxacin combined with dexamethasone was very effective in young rats without permanent bilateral carotid occlusion. The treatment reached reasonable results in older rats with PBCO, even considering residual abscesses on abdomen and thorax. Older age was the greater risk factor for the outcome of the treatment of severe peritonitis. Sepsis remains a challenging situation, especially in elderly.

Gender analysis of moxifloxacin clinical trials

PURPOSE

To determine the inclusion of women and the sex-stratification of results in moxifloxacin Clinical Trials (CTs), and to establish whether these CTs considered issues that specifically affect women, such as pregnancy and use of hormonal therapies. Previous publications about women's inclusion in CTs have not specifically studied therapeutic drugs. Although this type of drug is taken by men and women at a similar rate, adverse effects occur more frequently in the latter.

METHODS

We reviewed 158 published moxifloxacin trials on humans, retrieved from MedLine and the Cochrane Library (1998-2010), to determine whether they complied with the gender recommendations published by U.S. Food and Drug Administration Guideline.

RESULTS

Of a total of 80,417 subjects included in the moxifloxacin CTs, only 33.7% were women in phase I, in contrast to phase II, where women accounted for 45%, phase III, where they represented 38.3% and phase IV, where 51.3% were women. About 40.9% (n=52) of trials were stratified by sex and 15.3% (n=13) and 9% (n=7) provided data by sex on efficacy and adverse effects, respectively. We found little information about the influence of issues that specifically affect women. Only 3 of the 59 journals that published the moxifloxacin CTs stated that authors should stratify their results by sex.

CONCLUSIONS

Women are under-represented in the published moxifloxacin trials, and this trend is more marked in phase I, as they comprise a higher proportion in the other phases. Data by sex on efficacy and adverse effects are scarce in moxifloxacin trials. These facts, together with the lack of data on women-specific issues, suggest that the therapeutic drug moxifloxacin is only a partially evidence-based medicine.

Penetration of moxifloxacin into liver tissue

Moxifloxacin is considered for treatment of pyogenic liver abscesses as well as antibiotic prophylaxis in the case of hepatobiliary interventions. The aim of this study was to provide data on the pharmacokinetic (PK) profile of moxifloxacin in serum and liver tissue of patients undergoing liver resection due to primary or secondary tumours of the liver. Patients scheduled for liver resection (n=34) received moxifloxacin 400 mg at randomised time intervals prior to surgery. Blood and healthy liver tissue were sampled 1.5-26 h after administration of moxifloxacin. Immediately after centrifugation, plasma was separated, frozen and stored until analysis. In a subgroup of 19 patients, additional plasma specimens were obtained after 2, 4, 8, 12, 24, 36 and 48 h to assess the PK profile. PK parameters of moxifloxacin were calculated applying a two-compartment model. Median (interquartile range) PK parameters were as follows: peak concentration at the end of moxifloxacin infusion (C(max)), 6.0 mg/L (4.8-7.1 mg/L); area under the concentration-time curve extrapolated to infinity (AUC(0-∞)), 51.1 mgh/L (40.3-57.7 mgh/L); elimination half-life, 13.2h (11.0-14.1 h); volume of distribution at steady state (V(ss)), 138.7 L (102.7-168.5 L); and total body clearance (CL), 7.8 L/h (6.9-9.9L/h). Mean tissue concentrations were 9.13 mg/kg after 1.6-2.4 h, 7.62 mg/kg after 2.6-4.9h, 7.48 mg/kg after 5.6-10.0 h and 6.24 mg/kg after 22.9-26.5 h. Mean tissue:serum ratios were 2.9, 3.4, 5.0 and 12.3, respectively. The lowest tissue concentration found in the study at any time point was 2.8 mg/kg. In conclusion, moxifloxacin rapidly penetrates into the liver tissue where its concentration remains high following intravenous administration. Therefore, intravenously applied moxifloxacin might be used for the treatment of bacterial liver infections such as pyogenic liver abscess as well as in pre-operative prophylaxis.

Moxifloxacin monotherapy for treatment of complicated intra-abdominal infections: a meta-analysis of randomised controlled trials

To evaluate the efficacy and safety of moxifloxacin monotherapy for treatment of complicated intra-abdominal infections. PubMed, EMBASE, Science Direct, ClinicalTrials.gov and Cochrane Central Register of Controlled Trials were searched to retrieve randomised controlled trials (RCTs) compared moxifloxacin monotherapy with other antibiotics in the treatment of complicated intra-abdominal infections from January 1999 to July 2011. A meta-analysis of all included randomised controlled trials was performed. Four randomised controlled trials including a total of 2444 patients with complicated intra-abdominal infections were included for meta-analysis. The results of the meta-analysis indicated that the moxifloxacin was associated with similar clinical cure rate (four RCTs, 1934 patients, OR = 0.80, 95% CI: 0.61, 1.04, p = 0.09), bacteriological success rates (four RCTs, 1484 patients, OR = 0.79, 95% CI: 0.59, 1.05, p = 0.11) and mortality (four RCTs, 2227 patients, OR = 0.91, 95% CI: 0.45, 1.83, p = 0.79) compared with the control group. The overall incidence of adverse events of moxifloxacin was significantly higher than that in the control group (three RCTs, 1367 patients, OR = 1.33, 95% CI: 1.07, 1.63, p = 0.008), although the incidence of drug-related adverse events (three RCTs, 1601 patients, OR = 1.13, 95% CI: 0.69, 1.85, p = 0.63) and serious adverse events (three RCTs, 1815 patients, OR = 1.23, 95% CI: 0.59, 2.60, p = 0.58) were similar between the compared treatment groups. Moxifloxacin is an effective and relatively safe option for the treatment of patients with intra-abdominal infections. Moxifloxacin monotherapy has similar efficacy to combination therapy.

Role of moxifloxacin for the treatment of community-acquired [corrected] complicated intra-abdominal infections in Taiwan

Complicated intra-abdominal infections (cIAIs) are common yet serious infections that can potentially lead to substantial morbidity and morbidity. As an essential adjunct to source control, the goals of antimicrobial therapy are to promote patient recovery, reduce recurrence risk, and prevent antimicrobial resistance. The current international guidelines on the empirical treatment of community-acquired complicated IAIs were published by the Infectious Diseases Society of America (IDSA) and Surgical Infections Society (SIS) in 2010. These guidelines all recommend the use of a fluoroquinolone (ciprofloxacin or levofloxacin) plus metronidazole for mild-to-moderate- and high-severity cases. Moxifloxacin monotherapy is recommended by the current IDSA/SIS guidelines for the treatment of mild-to-moderate complicated IAIs. Moxifloxacin has demonstrated a broad spectrum coverage of both aerobic and anaerobic pathogens, good tissue penetration into the gastrointestinal tract, and a good tolerability profile. Clinical data have demonstrated that moxifloxacin is at least as effective as other standard therapeutic regimens recommended by current clinical guidelines. Due to the high rates of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and fluoroquinolone-resistant Enterobacteriaceae among isolates causing community-acquired IAIs in Asia, any fluoroquinolones (including moxifloxacin) are not recommended as drugs of choice for the empirical treatment of community-acquired IAIs, particularly in countries (China, India, Thailand, and Vietnam) with fluoroquinolone resistance rates among Escherichia coli isolates of >20%. Given the low rates of fluoroquinolone-resistant (<20%) and extended-spectrum β-lactamase (ESBL)-producing (<10%) Enterobacteriaceae isolates associated community-acquired IAIs in Taiwan, it appears that moxifloxacin is considered an appropriate first-line therapy for patients with community-acquired complicated IAIs in this country.

Tissue penetration of moxifloxacin into human gallbladder wall in patients with biliary tract infections

OBJECTIVES

Moxifloxacin, the newest fourth-generation fluoroquinolone, has a broad spectrum of antibacterial activity covering both Gram-positive and Gram-negative aerobic and anaerobic bacteria and is therefore very well suited for the treatment of biliary tract infections. The present study aimed to determine the penetration of moxifloxacin into gallbladder tissue to evaluate its antibiotic potential in this indication.

PATIENTS AND METHODS

Hospitalized patients with acute cholecystitis received a single, 1 h infusion of 400 mg of moxifloxacin before cholecystectomy. Serum and gallbladder wall tissue samples were collected during surgery, and the moxifloxacin concentrations were measured by HPLC.

RESULTS

Sixteen patients (eight men and eight women) were included between January 2007 and April 2008. The time between start of infusion and gallbladder removal ranged from 50 min to 21 h 10 min. The serum concentration at the time of cholecystectomy was between 0.39 and 4.37 mg/L, and the tissue concentration between 1.73 and 17.08 mg/kg. The tissue-to-serum concentration ratio ranged from 1.72 to 6.33.

CONCLUSIONS

The results show that moxifloxacin penetrates well into gallbladder tissue and is therefore a therapeutic option for biliary tract infection. The highest concentrations in serum and gallbladder tissue were measured shortly after the end of a 1 h infusion. As perioperative prophylaxis, moxifloxacin should therefore be administered 30-60 min before the first surgical incision.

Moxifloxacin is non-inferior to combination therapy with ceftriaxone plus metronidazole in patients with community-origin complicated intra-abdominal infections

Management of community-origin complicated intra-abdominal infections (cIAIs) requires surgical intervention and antimicrobial therapy. This multinational, randomised, double-blind clinical trial carried out in Asia compared the efficacy and safety of moxifloxacin monotherapy and ceftriaxone/metronidazole combination therapy in adults with confirmed or suspected cIAI. Patients received surgical intervention and either intravenous (i.v.) moxifloxacin 400 mg once daily or i.v. ceftriaxone 2 g once daily plus i.v. metronidazole 500 mg twice daily. A total of 364 patients were randomised [intent-to-treat (ITT), moxifloxacin N=180, comparator N=181; per-protocol (PP), moxifloxacin N=174, comparator N=171]. The most common cIAI diagnosis was complicated appendicitis. Moxifloxacin was non-inferior to ceftriaxone/metronidazole in terms of clinical response at test-of-cure in the PP population [clinical cure, 90.2% for moxifloxacin vs. 96.5% for ceftriaxone/metronidazole; 95% confidence interval (CI) of the difference -11.7 to -1.7] and in the ITT population (87.2% for moxifloxacin vs. 91.2% for ceftriaxone/metronidazole; 95% CI -10.7 to 1.9). Bacteriological cure rates in the microbiologically evaluable population support the clinical results (89.4% for moxifloxacin vs. 95.9% for ceftriaxone/metronidazole; 95% CI -13.3 to -0.6). The incidence of treatment-emergent adverse events was similar for both treatment groups (moxifloxacin 31.7% vs. comparator 24.3%). These results confirm previous findings that moxifloxacin plus adequate source control is an appropriate treatment of cIAI.

Moxifloxacin for the treatment of patients with complicated intra-abdominal infections (the AIDA Study)

This prospective, randomized, open, international, multicenter study of adults with complicated intra-abdominal infections (cIAI) compared the efficacy and safety of sequential intravenous (i.v.) to oral (p.o.) moxifloxacin 400 mg once daily, with that of i.v. ceftriaxone 2 g once daily, plus metronidazole 500 mg three times daily, followed by p.o. amoxicillin/clavulanate 625 mg three times daily. The primary efficacy variable was clinical cure at test of cure (TOC) (day 28-42 after study entry) in the per protocol (PP) population. Of 595 patients in the study, 511 patients were valid for PP analysis (246 moxifloxacin, 265 ceftriaxone/metronidazole). Sequential moxifloxacin was noninferior to the comparator regimen--clinical cure rates at TOC were 80.9% versus 82.3% (moxifloxacin versus ceftriaxone/metronidazole; 95% CI -8.9, 4.2%). The incidence of adverse events was comparable between the two treatment groups. Therefore, sequential moxifloxacin monotherapy is as effective and safe as combination therapy with i.v. ceftriaxone plus i.v. metronidazole followed by oral amoxicillin/clavulanate for the treatment of cIAI.