Integrated results of 2 phase 3 studies comparing tigecycline and levofloxacin in community-acquired pneumonia

Clinical use of tigecycline may contribute to the widespread dissemination of carbapenem-resistant hypervirulent Klebsiella pneumoniae strains

The emergence of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) poses grave threats to human health. These strains increased dramatically in clinical settings in China in the past few years but not in other parts of the world. Four isogenic K. pneumoniae strains, including classical K. pneumoniae, carbapenem-resistant K. pneumoniae (CRKP), hypervirulent K. pneumoniae (hvKP) and CR-hvKP, were created and subjected to phenotypic characterization, competition assays, mouse sepsis model and rat colonization tests to investigate the mechanisms underlying the widespread nature of CR-hvKP in China. Acquisition of virulence plasmid led to reduced fitness and abolishment of colonization in the gastrointestinal tract, which may explain why hvKP is not clinically prevalent after its emergence for a long time. However, tigecycline treatment facilitated the colonization of hvKP and CR-hvKP and reduced the population of Lactobacillus spp. in animal gut microbiome. Feeding with Lactobacillus spp. could significantly reduce the colonization of hvKP and CR-hvKP in the animal gastrointestinal tract. Our data implied that the clinical use of tigecycline to treat carbapenem-resistant K. pneumoniae infections facilitated the high spread of CR-hvKP in clinical settings in China and demonstrated that Lactobacillus spp. was a potential candidate for anticolonization strategy against CR-hvKP.

Third-Generation Tetracyclines: Current Knowledge and Therapeutic Potential

Tetracyclines constitute a unique class of antibiotic agents, widely prescribed for both community and hospital infections due to their broad spectrum of activity. Acting by disrupting protein synthesis through tight binding to the 30S ribosomal subunit, their interference is typically reversible, rendering them bacteriostatic in action. Resistance to tetracyclines has primarily been associated with changes in pump efflux or ribosomal protection mechanisms. To address this challenge, tetracycline molecules have been chemically modified, resulting in the development of third-generation tetracyclines. These novel tetracyclines offer significant advantages in treating infections, whether used alone or in combination therapies, especially in hospital settings. Beyond their conventional antimicrobial properties, research has highlighted their potential non-antibiotic properties, including their impact on immunomodulation and malignancy. This review will focus on third-generation tetracyclines, namely tigecycline, eravacycline, and omadacycline. We will delve into their mechanisms of action and resistance, while also evaluating their pros and cons over time. Additionally, we will explore their therapeutic potential, analyzing their primary indications of prescription, potential future uses, and non-antibiotic features. This review aims to provide valuable insights into the clinical applications of third-generation tetracyclines, thereby enhancing understanding and guiding optimal clinical use.

Safety and effectiveness of tigecycline combination therapy in renal transplant patients with infection due to carbapenem-resistant gram-negative bacteria

Background

Carbapenem-resistant gram-negative bacterial (CRGNB) infections are increasing among kidney transplant recipients, and effective therapeutic options are limited. This study aimed to investigate the efficacy and adverse events associated with combination therapy tigecycline in renal transplant patients with CRGNB infections.

Methods

This study retrospectively analyzed 40 Chinese patients with confirmed or suspected CRGNB infections who received tigecycline therapy. The patients' case features and clinical and microbiological data were analyzed.

Results

A total of 40 renal transplant recipients received tigecycline therapy for a median duration of 9 (range, 3-25) days. CRGNB isolates were obtained from the organ preservation solution of the donor kidney in 28 patients, with confirmed transmission in 4 patients. Infections were detected in the bloodstream, urinary tract, sputum, and wound. The most prevalent isolates were Klebsiella pneumoniae (75%, 30/40), Acinetobacter baumannii (15%, 6/40), and Escherichia coli (10%, 4/40). A clinical response was observed in 32 (80%) patients. The 28-day all-cause mortality rate was 7.5% (3/40), while the one-year all-cause mortality rate was 2.5% (1/40). While one patient died owing to severe pancreatitis, no serious adverse events related to tigecycline therapy were reported. However, multiple indices of liver function and pancreatitis precursors increased after treatment with tigecycline compared to before treatment.

Conclusion

Tigecycline therapy appears to be well tolerated in renal transplant recipients with multidrug-resistant bacterial infections. Nevertheless, attention should be paid to adverse reactions related to tigecycline therapy, especially gastrointestinal reactions, and the related laboratory tests should be closely monitored.

Tigecycline treatment causes a decrease in peripheral blood platelet

Tigecycline with broad-spectrum activity against pathogens has advantages in the treatment of severe infections in clinical. Accompany with the huge increase of tigecycline usage, more side effects began to arouse people's attention. The aim of this study was to assess the impact of tigecycline treatment on peripheral blood platelet in patients with severe infections. We retrospectively retrieved demographic and laboratory data in 24 cases of tigecycline-treated patients with severe infections. 18 patients (75%) who were administered tigecycline experienced a decrease in platelet count. The ages of platelet decrease group are significant older than normal group. In the platelet decreased group, the platelet count was significant decreased after 3 days tigecycline treatment. 9 patients' platelet count recovered in 5 days after tigecycline treatment withdraw. Platelet decrease in patient after tigecycline treatment, which can be reversed after tigecycline discontinuation. Tigecycline-induced platelet decrease is associated with age.

Safety of Tigecycline in Patients on Antithrombotic Therapy: A Single-Center Retrospective Study

INTRODUCTION

The aims of the study were to investigate the risk factors of tigecycline-induced hypofibrinogenemia and to evaluate the safety of tigecycline with concomitant antithrombotic drugs.

METHODS

We performed a retrospective analysis of patients who received tigecycline for more than 3 days between January 2015 and June 2019. Clinical and laboratory data were collected including fibrinogen concertation, tigecycline dose, duration of treatment, disease severity, complete blood count, indicators of infection, liver and renal function. Risk factors of hypofibrinogenemia were analyzed by univariate and multivariate analysis. To evaluate the safety of tigecycline and concomitant antithrombotic drugs, bleeding events were assessed by comparing the decline in hemoglobin and the amount of red blood cell transfusion in patients with antithrombotic drugs and those without.

RESULTS

This study included a total of 68 cases, 20 of which experienced hypofibrinogenemia while receiving tigecycline treatment. Duration of treatment, cefoperazone/sulbactam combination therapy, and fibrinogen levels prior to initiation of tigecycline were risk factors associated with tigecycline-induced hypofibrinogenemia. There were 26 recorded bleeding incidents, 25 of which happened before the start of tigecycline. Antithrombotic and non-antithrombotic patients did not differ in their hemoglobin decline or need for red blood cell transfusions while taking tigecycline.

CONCLUSION

A longer treatment duration, cefoperazone/sulbactam combination therapy, and a lower level of fibrinogen before tigecycline were associated with an increased risk of tigecycline-induced hypofibrinogenemia. A combination of antithrombotic drugs and tigecycline did not aggravate the bleeding events during tigecycline treatment.

Acute pancreatitis caused by tigecycline: A case report and literature review

RATIONALE

There is evidence that tigecycline has broad-spectrum antibiotic activity against a variety of complicated infections. However, adverse effects are inevitable, including gastrointestinal side effects such as nausea, vomiting, and diarrhea; in 2006, acute pancreatitis was also brought into the side-effect list after postmarketing surveillance. Here, we present a case of tigecycline-induced acute pancreatitis.

PATIENT CONCERNS

An 87-year-old female patient with urinary tract infection received an intravenous drip of tigecycline for 6 days, after which she developed abdominal distension, vomiting, abdominal pain, and abdominal rigidity.

DIAGNOSIS

The patient was suspected to have tigecycline-induced acute pancreatitis.

INTERVENTIONS

Tigecycline was discontinued immediately, and the patient received a series of immediate treatments including an indwelling gastric tube for continuous gastrointestinal decompression and inhibition of gastric acid and pancreatic enzyme secretion.

OUTCOMES

Following initial interventions, we observed that the patient's symptoms improved significantly, and abdominal distension, vomiting, abdominal pain, and abdominal rigidity were slightly relieved. After 5 days of follow-up, blood lipase and amylase levels decreased to normal levels. Unfortunately, the patient developed convulsions during the use of multiple antibiotics after 1 week and then died of septic shock and acute liver failure.

LESSONS

Acute pancreatitis caused by tigecycline is rare. However, in the application of antibiotics, the possibility of adverse effects must be considered, and antibiotics should be used reasonably. If the patient has relevant symptoms, it is necessary to stop using tigecycline immediately, carry out symptomatic treatment, and change to other types of antibiotics for antibacterial treatment.

The Development of Third-Generation Tetracycline Antibiotics and New Perspectives

The tetracycline antibiotic class has acquired new valuable members due to the optimisation of the chemical structure. The first modern tetracycline introduced into therapy was tigecycline, followed by omadacycline, eravacycline, and sarecycline (the third generation). Structural and physicochemical key elements which led to the discovery of modern tetracyclines are approached. Thus, several chemical subgroups are distinguished, such as glycylcyclines, aminomethylcyclines, and fluorocyclines, which have excellent development potential. The antibacterial spectrum comprises several resistant bacteria, including those resistant to old tetracyclines. Sarecycline, a narrow-spectrum tetracycline, is notable for being very effective against Cutinebacterium acnes. The mechanism of antibacterial action from the perspective of the new compound is approached. Several severe bacterial infections are treated with tigecycline, omadacycline, and eravacycline (with parenteral or oral formulations). In addition, sarecycline is very useful in treating acne vulgaris. Tetracyclines also have other non-antibiotic properties that require in-depth studies, such as the anti-inflammatory effect effect of sarecycline. The main side effects of modern tetracyclines are described in accordance with published clinical studies. Undoubtedly, this class of antibiotics continues to arouse the interest of researchers. As a result, new derivatives are developed and studied primarily for the antibiotic effect and other biological effects.

Safety and Efficacy of Tigecycline in Intensive Care Unit Patients Based on Therapeutic Drug Monitoring

OBJECTIVE

Tigecycline exerts significant beneficial effects against drug-resistant bacterial infections. The largely empirical medications used in clinical practice are often associated with wide individual differences in efficacy and safety. We investigated the associations between the pharmacokinetics of tigecycline and its efficacy and safety in intensive care unit (ICU) patients, with the aim of facilitating clinical applications of tigecycline.

METHODS

ICU patients who were prescribed tigecycline in a hospital setting were prospectively included. Factors related to the clinical efficacy and safety of tigecycline were assessed by univariate and multivariate analyses.

RESULTS

This study included 45 patients, from whom a total of 63 blood samples were collected to determine steady-state trough plasma concentrations (Cmin) of tigecycline. The Cmin of tigecycline was 417.1 ± 263.8 ng/mL (mean ± SD). The multivariate analysis showed that the APACHE II scores [odds ratio (OR) = 0.874, 95% confidence interval (CI) = 0.733-0.901, P = 0.048] were significantly correlated with the efficacy of tigecycline, whereas there was no correlation between Cmin of tigecycline and efficacy. In safety, the risk factors significantly associated with hepatotoxicity were sex (OR = 0.562, 95% CI = 0.191-0.774, P = 0.023), APACHE II score (OR = 1.061, 95% CI = 1.039-1.392, P = 0.045), and Cmin (OR = 1.210, 95% CI = 1.014-1.336, P = 0.008). The optimal cut-off for hepatotoxicity in ICU patients treated with tigecycline was 474.8 ng/mL.

CONCLUSIONS

There was considerable variability in the Cmin of tigecycline among the ICU patients in this study and it is at risk of high exposure in women. Cmin can be a useful predictor of hepatotoxicity with a cut-off of 474.8 ng/mL.

Antimicrobial Resistance in ESKAPE Pathogens

Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.

Antimicrobial Resistance in ESKAPE Pathogens

Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.

Susceptibility of Rickettsia rickettsii to Tigecycline in a Cell Culture Assay and Animal Model for Rocky Mountain Spotted Fever

Rocky Mountain spotted fever (RMSF), caused by Rickettsia rickettsii, is a severe tick-borne infection endemic to the Americas. Oral doxycycline is effective, but during severe life-threatening disease, intravenous therapy is recommended. Unfortunately, intravenous formulations of doxycycline are not always available. Therefore, we aimed to determine the susceptibility of R. rickettsii to an alternative parenteral agent, tigecycline, in vitro and in vivo. To determine the minimum inhibitory concentration of tigecycline, R. rickettsii-inoculated Vero cells were incubated with medium containing tigecycline. At various time points, monolayers were collected and R. rickettsii was quantified via real-time polymerase chain reaction (PCR). The growth of R. rickettsii was inhibited in the presence of ≥ 0.5 µg/mL of tigecycline. To determine the effectiveness of tigecycline in vivo, guinea pigs were inoculated with R. rickettsii. Five days after inoculation, they were treated twice daily with subcutaneous tigecycline 3.75 mg/kg or subcutaneous doxycycline 5 mg/kg. Treated animals improved, whereas untreated controls remained ill. Tissues were collected for quantitative PCR-determined bacterial loads on day 8. Median bacterial loads in the tigecycline group were less than those in untreated animals: liver (0 versus 2.9 × 10⁴ copies/mg), lung (0 versus 8.3 × 10³ copies/mg), skin (2.6 × 10² versus 2.2 × 10⁵ copies/mg), spleen (0 versus 1.3 × 10⁴ copies/mg), and testes (0 versus 1.0 × 10⁵ copies/mg, respectively). There were no significant differences in the bacterial loads between doxycycline-treated versus tigecycline-treated guinea pigs. These data indicate that tigecycline is effective against R. rickettsii in cell culture and in an animal model of RMSF.

Methicillin-resistant Staphylococcus aureus: an overview of basic and clinical research

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most successful modern pathogens. The same organism that lives as a commensal and is transmitted in both health-care and community settings is also a leading cause of bacteraemia, endocarditis, skin and soft tissue infections, bone and joint infections and hospital-acquired infections. Genetically diverse, the epidemiology of MRSA is primarily characterized by the serial emergence of epidemic strains. Although its incidence has recently declined in some regions, MRSA still poses a formidable clinical threat, with persistently high morbidity and mortality. Successful treatment remains challenging and requires the evaluation of both novel antimicrobials and adjunctive aspects of care, such as infectious disease consultation, echocardiography and source control. In this Review, we provide an overview of basic and clinical MRSA research and summarize the expansive body of literature on the epidemiology, transmission, genetic diversity, evolution, surveillance and treatment of MRSA.

Busting the Myth of "Static vs Cidal": A Systemic Literature Review

We sought to determine if clinical data validate the dogma that bactericidal antibiotics are more clinically effective than bacteriostatic agents. We performed a systematic literature review of published, randomized, controlled trials (RCTs) that compared a bacteriostatic agent to a bactericidal agent in the treatment of clinical, bacterial infections. Of 56 identified trials published since 1985, 49 found no significant difference in efficacy between bacteriostatic and bactericidal agents. In 6 trials it was found that the bacteriostatic agent was superior to the bactericidal agent in efficacy. Only 1 trial found that the bactericidal agent was superior; in that case, the inferiority of the static agent was explainable by underdosing of the drug based on pharmacokinetic-pharmacodynamic analysis. Thus, virtually all available data from high-quality, RCTs demonstrate no intrinsic superiority of bactericidal compared to bacteriostatic agents. Other drug characteristics such as optimal dosing, pharmacokinetics, and tissue penetration may be more important efficacy drivers.

Successful Treatment of Legionnaires' Disease with Tigecycline in an Immunocompromised Man with a Legion of Antibiotic Allergies

Legionella species are Gram-negative bacilli that are relatively rare causes of community-acquired pneumonia but can be associated with significant morbidity and mortality if unrecognized or improperly treated. Limited data exist regarding the use of tigecycline, a third generation glycylcycline, in the treatment of Legionnaires' disease. We present an immunocompromised patient with Legionnaires' disease and allergies to both fluoroquinolones and macrolides, which are first-line treatment options for Legionnaires' disease. He was successfully treated using tigecycline, a third generation glycylcycline, indicating that tigecycline may serve as a safe and effective alternative therapeuticl option for treatment of Legionnaires’ disease.

Treatment of infections caused by multidrug-resistant Gram-negative bacteria: report of the British Society for Antimicrobial Chemotherapy/Healthcare Infection Society/British Infection Association Joint Working Party

The Working Party makes more than 100 tabulated recommendations in antimicrobial prescribing for the treatment of infections caused by multidrug-resistant (MDR) Gram-negative bacteria (GNB) and suggest further research, and algorithms for hospital and community antimicrobial usage in urinary infection. The international definition of MDR is complex, unsatisfactory and hinders the setting and monitoring of improvement programmes. We give a new definition of multiresistance. The background information on the mechanisms, global spread and UK prevalence of antibiotic prescribing and resistance has been systematically reviewed. The treatment options available in hospitals using intravenous antibiotics and in primary care using oral agents have been reviewed, ending with a consideration of antibiotic stewardship and recommendations. The guidance has been derived from current peer-reviewed publications and expert opinion with open consultation. Methods for systematic review were NICE compliant and in accordance with the SIGN 50 Handbook; critical appraisal was applied using AGREE II. Published guidelines were used as part of the evidence base and to support expert consensus. The guidance includes recommendations for stakeholders (including prescribers) and antibiotic-specific recommendations. The clinical efficacy of different agents is critically reviewed. We found there are very few good-quality comparative randomized clinical trials to support treatment regimens, particularly for licensed older agents. Susceptibility testing of MDR GNB causing infection to guide treatment needs critical enhancements. Meropenem- or imipenem-resistant Enterobacteriaceae should have their carbapenem MICs tested urgently, and any carbapenemase class should be identified: mandatory reporting of these isolates from all anatomical sites and specimens would improve risk assessments. Broth microdilution methods should be adopted for colistin susceptibility testing. Antimicrobial stewardship programmes should be instituted in all care settings, based on resistance rates and audit of compliance with guidelines, but should be augmented by improved surveillance of outcome in Gram-negative bacteraemia, and feedback to prescribers. Local and national surveillance of antibiotic use, resistance and outcomes should be supported and antibiotic prescribing guidelines should be informed by these data. The diagnosis and treatment of both presumptive and confirmed cases of infection by GNB should be improved. This guidance, with infection control to arrest increases in MDR, should be used to improve the outcome of infections with such strains. Anticipated users include medical, scientific, nursing, antimicrobial pharmacy and paramedical staff where they can be adapted for local use.

Tigecycline-induced acute pancreatitis in a renal transplant patient: a case report and literature review

Background

The purpose of this case report is to increase the awareness of tigecycline-induced pancreatitis specifically in renal transplant patients predisposed to the condition.

Case presentation

A 48-year-old woman developed a donor-derived infection after kidney transplantation, resulting in a ruptured graft renal artery, followed by peritoneal drainage, blood and urine culture infections. Due to multiple drug resistance Acinetobacter baumannii cultured from the preservation fluid and blood, she was treated with tigecycline at the 8th post-transplant day combined with other antibiotics. After 15 days of tigecycline treatment, she was observed with recurrent fever and abdominal distension with a rise in pancreatic enzymes. CT scans showed acute pancreatitis with grade D on Balthazar score, no necrosis visible without contrast injection. These facts were sufficient to hint that pancreatitis was slowly becoming prominent. After withdrawal of tigecycline, CT scans showed that exudation around the pancreas were relieved, and blood amylase returned to the normal range in a week.

Conclusions

Clinicians should pay attention to clinical signs and symptoms and the level of serum pancreatic enzymes in order to monitor the development of pancreatitis. If necessary, abdominal CT scans should be performed regularly when given tigecycline.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3103-z) contains supplementary material, which is available to authorized users.

Comparison of Omadacycline and Tigecycline Pharmacokinetics in the Plasma, Epithelial Lining Fluid, and Alveolar Cells of Healthy Adult Subjects

The steady-state concentrations of omadacycline and tigecycline in the plasma, epithelial lining fluid (ELF), and alveolar cells (AC) of 58 healthy adult subjects were obtained. Subjects were administered either omadacycline at 100 mg intravenously (i.v.) every 12 h for two doses followed by 100 mg i.v. every 24 h for three doses or tigecycline at an initial dose of 100 mg i.v. followed by 50 mg i.v. every 12 h for six doses. A bronchoscopy and bronchoalveolar lavage were performed once in each subject following the start of the fifth dose of omadacycline at 0.5, 1, 2, 4, 8, 12, or 24 h and after the start of the seventh dose of tigecycline at 2, 4, 6, or 12 h. The value of the area under the concentration-time curve (AUC) from time zero to 24 h postdosing (AUC_0–24) (based on mean concentrations) in ELF and the ratio of the ELF to total plasma omadacycline concentration based on AUC_0–24 values were 17.23 mg · h/liter and 1.47, respectively. The AUC_0–24 value in AC was 302.46 mg · h/liter, and the ratio of the AC to total plasma omadacycline concentration was 25.8. In comparison, the values of the AUC from time zero to 12 h postdosing (AUC_0–12) based on the mean concentrations of tigecycline in ELF and AC were 3.16 and 38.50 mg · h/liter, respectively. The ratio of the ELF and AC to total plasma concentrations of tigecycline based on AUC_0–12 values were 1.71 and 20.8, respectively. The pharmacokinetic advantages of higher and sustained concentrations of omadacycline compared to those of tigecycline in plasma, ELF, and AC suggest that omadacycline is a promising antibacterial agent for the treatment of lower respiratory tract bacterial infections caused by susceptible pathogens.

The efficacy and safety of tigecycline for the treatment of bloodstream infections: a systematic review and meta-analysis

Patients with bloodstream infections (BSI) are associated with high mortality rates. Due to tigecycline has shown excellent in vitro activity against most pathogens, tigecycline is selected as one of the candidate drugs for the treatment of multidrug-resistant organisms infections. The purpose of this study was to evaluate the effectiveness and safety of the use of tigecycline for the treatment of patients with BSI. The PubMed and Embase databases were systematically searched, to identify published studies, and we searched clinical trial registries to identify completed unpublished studies, the results of which were obtained through the manufacturer. The primary outcome was mortality, and the secondary outcomes were the rate of clinical cure and microbiological success. 24 controlled studies were included in this systematic review. All-cause mortality was lower with tigecycline than with control antibiotic agents, but the difference was not significant (OR 0.85, [95% confidence interval (CI) 0.31-2.33; P = 0.745]). Clinical cure was significantly higher with tigecycline groups (OR 1.76, [95% CI 1.26-2.45; P = 0.001]). Eradication efficiency did not differ between tigecycline and control regimens, but the sample size for these comparisons was small. Subgroup analyses showed good clinical cure result in bacteremia patients with CAP. Tigecycline monotherapy was associated with a OR of 2.73 (95% CI 1.53-4.87) for mortality compared with tigecycline combination therapy (6 studies; 250 patients), without heterogeneity. Five studies reporting on 398 patients with Klebsiella pneumoniae carbapenemase-producing K. pneumoniae BSI showed significantly lower mortality in the tigecycline arm than in the control arm. The combined treatment with tigecycline may be considered the optimal option for severely ill patients with BSI.

Prescription Patterns for Tigecycline in Severely Ill Patients for Non-FDA Approved Indications in a Developing Country: A Compromised Outcome

Introduction: With the rise in antibiotic resistance, tigecycline has been used frequently in off-label indications, based on its in-vitro activity against multidrug-resistant organisms. In this study, our aim was to assess its use in approved and unapproved indications.

Materials and Methods: This is a retrospective chart review evaluating a 2-year experience of tigecycline use for > 72 h in 153 adult patients inside and outside critical care unit from January 2012 to December 2013 in a Lebanese tertiary-care hospital.

Results: Tigecycline was mostly used in off-label indications (81%) and prescribed inside the critical care area, where the number of tigecycline cycles was 16/1,000 patient days. Clinical success was achieved in 43.4% of the patients. In the critically ill group, it was significantly higher in patients with a SOFA score <7 using multivariate analysis (Odds Ratio (OR) = 12.51 [4.29–36.51], P < 0.0001). Microbiological success was achieved in 43.3% of patients. Yet, the univariate and adjusted multivariate models failed to show a significant difference in this outcome between patients inside vs. outside critical care area, those with SOFA score <7 vs. ≥ 7, and in FDA-approved vs. off-label indications. Total mortality reached ~45%. It was significantly higher in critically ill patients with SOFA score ≥7 (OR = 5.17 [2.43–11.01], P < 0.0001) and in off-label indications (OR = 4.00 [1.30–12.31], P = 0.01) using an adjusted multivariate model. Gram-negative bacteria represented the majority of the clinical isolates (81%) and Acinetobacter baumannii predominated (28%). Carbapenem resistance was present in 85% of the recovered Acinetobacter, yet, more than two third of the carbapenem-resistant Acinetobacter species were still susceptible to tigecycline.

Conclusion: In our series, tigecycline has been mostly used in off-label indications, specifically in severely ill patients. The outcome of such infections was not inferior to that of FDA-approved indications, especially inside critical care area. The use of this last resort antibiotic in complicated clinical scenarios with baseline microbiological epidemiology predominated by extensively-drug resistant pathogens ought to be organized.

Efficacy of tigecycline for secondary Acinetobacter bacteremia and factors associated with treatment failure

We describe the clinical outcome of 17 patients with secondary Acinetobacter bacteremia whose isolates had a tigecycline MIC of ≤2 mg/liter and who received tigecycline within 2 days of bacteremia onset. The 14-day mortality rate of the tigecycline cohort was 41.2% (7/17), which was significantly higher than that of those receiving other appropriate antimicrobial agents (13.8%, 9/65; P = 0.018). However, the percentages of end-stage renal disease and congestive heart failure were higher in the tigecycline cohort. The efficacy of tigecycline was contingent upon the illness severity and bacterial species. Tigecycline should be applied cautiously for treatment of Acinetobacter bacteremia.

Tigecycline : a critical safety review

INTRODUCTION

The emergence of multidrug-resistant (MDR) infections has been extensively observed worldwide and has become a priority issue over past decade. Tigecycline , a broad spectrum antibiotic covering against many MDR organisms, has been widely used. However, recent meta-analysis studies have raised a concern for its efficacy and safety. Reviewing tigecycline safety data would enhance the appropriate use of this medication.

AREAS COVERED

This article reviews the safety profile of tigecycline, including its side effects and drug interactions.

EXPERT OPINION

The increased mortality associated with tigecycline is not yet well understood. Based on current evidence, alternative options must be prioritized over tigecycline if available. When tigecycline use is warranted, vigilant observation to identify any breakthrough infections and careful monitoring of progression of the original infection are highly recommended. Considering a second agent (either for synergism or enhancing coverage) may be required.

Treatment of Gram-positive infections in critically ill patients

Gram-positive bacteria to include methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible Staphylococcus aureus (MSSA), and enterococci, to include vancomycin-resistant enterococci (VRE), display a remarkable array of resistance and virulence factors, which have contributed to their prominent role in infections of the critically ill. Over the last three decades infections with these pathogens has increased as has their overall resistance to available antimicrobial agents. This has led to the development of a number of new antibiotics for the treatment of Gram-positive bacteria. At present, it is important that clinicians recognize the changing resistance patterns and epidemiology of Gram-positive bacteria as these factors may impact patient outcomes. The increasing range of these pathogens, such as the emergence of community-associated MRSA clones, emphasizes that all specialties of physicians treating infections should have a good understanding of the infections caused by Gram-positive bacteria in their area of practice. When initiating empiric antibiotics, it is of vital importance that this therapy be timely and appropriate, as delays in treatment are associated with adverse outcomes. Although vancomycin has traditionally been considered a first-line therapy for serious MRSA infections, multiple concerns with this agent have opened the door for alternative agents demonstrating efficacy in this role. Similarly, the expansion of VRE as a pathogen in the ICU setting has required the development of agents targeting this important pathogen.

Regional and global antimicrobial susceptibility among isolates of Streptococcus pneumoniae and Haemophilus influenzae collected as part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) from 2009 to 2012 and comparison with previous years of T.E.S.T. (2004-2008)

BACKGROUND

We report here on 14438 Streptococcus pneumoniae and 14770 Haemophilus influenzae isolates collected from 560 centres globally between 2004 and 2012 as a part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.).

METHODS

MIC testing was performed using broth microdilution methods as described by the Clinical and Laboratory Standards Institute (CLSI) using CLSI-approved breakpoints; US Food and Drug Administration breakpoints were used for tigecycline as CLSI breakpoints are not available.

RESULTS

At least 99% of S. pneumoniae isolates globally were susceptible to levofloxacin, linezolid, tigecycline or vancomycin. Penicillin resistance was observed among 14.8% of S. pneumoniae and was highest in Asia/Pacific Rim (30.1%) and Africa (27.6%); 23.4% of S. pneumoniae isolates were penicillin-intermediate, which were most common in Africa (37.6%). Minocycline susceptibility among S. pneumoniae decreased by 20% between 2004-2008 and 2009-2012. High (>98.5%) susceptibility was reported among H. influenzae to all antimicrobial agents on the T.E.S.T. panel excluding ampicillin, to which only 78.3% were susceptible. β-lactamase production was observed among 20.2% of H. influenzae isolates; 1.5% of isolates were β-lactamase negative, ampicillin-resistant.

CONCLUSIONS

S. pneumoniae remained highly susceptible to levofloxacin, linezolid, tigecycline and vancomycin while H. influenzae was susceptible to most antimicrobial agents in the testing panel (excluding ampicillin).

Tigecycline use in critically ill patients: a multicentre prospective observational study in the intensive care setting

PURPOSE

This prospective observational study aimed at describing prescription patterns of tigecycline and patient outcomes in 26 French intensive care units (ICU).

METHODS

Data of consecutive cases of adult patients treated with tigecycline were collected from the initiation until 7 days after the end of treatment. Response to treatment was classified as success, failure or undetermined and analyses were presented according to severity (SOFA score <7 or ≥7). Survival was recorded at 28 days.

RESULTS

A total of 156 patients were included (64% male, age 60 ± 15 years). At inclusion, 53% had a SOFA score ≥7; 93% had received prior anti-infective agents. Tigecycline was given as first-line treatment in 47% of patients, mostly in combination (67%), for intra-abdominal (IAI 56%), skin and soft tissue (SSTI 19%) or other infections. A total of 76% of the treated infections were hospital-acquired. Bacteraemia was reported in 12% of patients. Median treatment duration was 9 days. Tigecycline was prematurely stopped in 42% patients. The global success rate was 60% at the end of treatment, and significantly higher with treatment duration more than 9 days (76 vs. 47%, P < 0.001). Success rate was 65% for patients alive at the end of treatment. Success rates tended to decrease with illness severity, immunosuppression, bacteraemia and obesity. Survival rate at day 28 was 85% in the whole cohort and significantly higher in the less severely ill patients (P < 0.001).

CONCLUSIONS

Tigecycline success rates appear comparable to those reported in clinical studies in ICU with severe infections. Tigecycline could be an alternative in ICU patients.

Quantitative analysis and pharmacokinetics study of tigecycline in human serum using a validated sensitive liquid chromatography with tandem mass spectrometry method

Tigecycline, a novel intravenously administered glycylcycline antibiotic, currently plays a key role in the management of complicated multiorganism infections. However, current liquid chromatography with tandem mass spectrometry methods briefly describe parameters and the only reported internal standard was sometimes difficult to obtain. In our study, an updated liquid chromatography with tandem mass spectrometry method for the quantitative analysis of tigecycline in human serum was developed. Sample preparation involved precipitation with 20% trichloroacetic acid. Chromatographic separation of tigecycline and tetracycline (internal standard) was achieved on a Hypersil GOLD C18 column using gradient elution. The selected reaction monitoring transitions were performed at m/z 586.1→513.2 for tigecycline and m/z 445.1→410.2 for tetracycline. The assay was linear over the concentration range of 5-2000 ng/mL. The intra- and interday precisions at three concentration levels (10, 100, and 1600 ng/mL) were <15% and their accuracies were within the range of 95.1-106.1%. The mean recovery ranged from 94.3 to 105.6% and the matrix effect from 92.1 to 97.6%. Tigecycline was stable under all tested conditions. This validated method was successfully applied to a pharmacokinetic study in critically ill patients. The data demonstrated that our method allows quantification of tigecycline in serum in a quick and reliable manner for widespread application.

Antimicrobial susceptibility of Gram-negative organisms isolated from patients hospitalised with pneumonia in US and European hospitals: results from the SENTRY Antimicrobial Surveillance Program, 2009-2012

Here we evaluated the frequency of occurrence and antimicrobial susceptibility patterns of Gram-negative bacteria isolated from patients hospitalised with pneumonia in medical centres in the USA (n=28) and Europe and the Mediterranean region (EMR) (n=25) in 2009-2012. Susceptibility testing was performed by reference broth microdilution methods. Overall, 12851 isolates were collected (6873/5978 in USA/EMR). The same top 11 organisms were observed in both geographic regions, but in different rank orders, and Gram-negative organisms represented 61.5/76.1% of strains in USA/EMR. Pseudomonas aeruginosa was the most frequently isolated Gram-negative organism in both regions (20.9/20.9% of cases in USA/EMR) and showed reduced susceptibility to most antimicrobials tested, including ceftazidime (79.6/68.7% susceptibility in USA/EMR), meropenem (76.3/65.8%) and piperacillin/tazobactam (72.9/63.9%). Klebsiella spp. was isolated from 9.7/11.6% of cases and showed extended-spectrum β-lactamase (ESBL) phenotype rates of 19.5/35.1% in USA/EMR. Meropenem and amikacin were active against 62.3/78.7% and 60.8/85.2% of ESBL phenotype Klebsiella spp. from USA/EMR, respectively. Enterobacter spp. ranked fourth in the USA (5.9%) and sixth in EMR (5.5%), whereas Escherichia coli ranked fifth in the USA (5.5%) and third in EMR (11.8%). Acinetobacter spp. and Stenotrophomonas maltophilia combined were isolated from 8.0/10.7% of cases in USA/EMR. A significant increase in P. aeruginosa susceptibility to meropenem and a significant decrease in gentamicin susceptibility among Klebsiella spp. were noted in EMR. These results confirm that very few agents remain broadly active against the most frequently isolated Gram-negative organisms from patients with pneumonia in US and EMR medical centres.

Phase 3 study comparing tigecycline and ertapenem in patients with diabetic foot infections with and without osteomyelitis

A phase 3, randomized, double-blind trial was conducted in subjects with diabetic foot infections without osteomyelitis (primary study) or with osteomyelitis (substudy) to determine the efficacy and safety of parenteral (intravenous [iv]) tigecycline (150 mg once-daily) versus 1 g once-daily iv ertapenem ± vancomycin. Among 944 subjects in the primary study who received ≥1 dose of study drug, >85% had type 2 diabetes; ~90% had Perfusion, Extent, Depth/tissue loss, Infection, and Sensation infection grade 2 or 3; and ~20% reported prior antibiotic failure. For the clinically evaluable population at test-of-cure, 77.5% of tigecycline- and 82.5% of ertapenem ± vancomycin-treated subjects were cured. Corresponding rates for the clinical modified intent-to-treat population were 71.4% and 77.9%, respectively. Clinical cure rates in the substudy were low (<36%) for a subset of tigecycline-treated subjects with osteomyelitis. Nausea and vomiting occurred significantly more often after tigecycline treatment (P = 0.003 and P < 0.001, respectively), resulting in significantly higher discontinuation rates in the primary study (nausea P = 0.007, vomiting P < 0.001). In the primary study, tigecycline did not meet criteria for noninferiority compared with ertapenem ± vancomycin in the treatment of subjects with diabetic foot infections.

Frontline antibiotic therapy

The need to use front-line antibiotics wisely has never been greater. Antibiotic resistance and multi-drug resistant infection, driven by antibiotic use, remain major public health and professional concerns. To overcome these infection problems, use of older antibiotics active against multi drug-resistant pathogens is increasing - for example, colistin, fosfomycin, pivmecillinam, pristinamycin, temocillin and oral tetracyclines. The number of new antibacterials reaching clinical practice has reduced significantly in the last 20 years, most being focused on therapy of Gram-positive infection - eg linezolid, daptomycin, telavancin and ceftaroline. Recent guidance on antibiotic stewardship in NHS trusts in England is likely to provide a backdrop to antibiotic use in hospitals in the next 5 years.

Tigecycline versus levofloxacin in hospitalized patients with community-acquired pneumonia: an analysis of risk factors

INTRODUCTION

This study was conducted to evaluate the efficacy of tigecycline (TGC) versus levofloxacin (LEV) in hospitalized patients with community-acquired pneumonia (CAP) using pooled data and to perform exploratory analyses of risk factors associated with poor outcome.

MATERIALS AND METHODOLOGY

Pooled analyses of 2 phase 3 studies in patients randomized to intravenous (IV) TGC (100 mg, then 50 mg q12h) or IV LEV (500 mg q24h or q12h). Clinical responses at test of cure visit for the clinically evaluable (CE) and clinical modified intention to treat populations were assessed for patients with risk factors including aged ≥65 years, prior antibiotic failure, bacteremia, multilobar disease, chronic obstructive pulmonary disease, alcohol abuse, altered mental status, hypoxemia, renal insufficiency, diabetes mellitus, white blood cell count >30 x 10(9)/L or <4 x 10(9)/L, CURB-65 score ≥2, Fine score category of III to V and at least 2 clinical instability criteria on physical examination.

RESULTS

In the CE population of 574 patients, overall cure rates were similar: TGC (253/282, 89.7%); LEV (252/292, 86.3%). For all but one risk factor, cure rates for TGC were similar to or higher than those for LEV. For individual risk factors, the greatest difference between treatment groups was observed in patients with diabetes mellitus (difference of 22.9 for TGC versus LEV; 95% confidence interval, 4.8 - 39.9).

CONCLUSIONS

TGC achieved cure rates similar to those of LEV in hospitalized patients with CAP. For patients with risk factors, TGC provided generally favorable clinical outcomes.

Emergency management of community-acquired bacterial pneumonia: what is new since the 2007 Infectious Diseases Society of America/American Thoracic Society guidelines

Community-acquired pneumonia (CAP) is a major health problem in the United States and is associated with substantial morbidity, mortality, and health care costs. Patients with CAP commonly present to emergency departments where physicians must make critical decisions regarding diagnosis and management of pneumonia in a timely fashion, with emphasis on efficient and cost-effective diagnostic choices, consideration of emerging antimicrobial resistance, timely initiation of antibiotics, and appropriate site-of-care decisions. In light of the burden that pneumonia places on health care systems and the emergency department in particular, this article reviews significant developments in the management of CAP in the United States 5 years since the publication of the 2007 Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of CAP in adults, focusing on recent studies and recommendations for managing CAP, the primary bacterial pathogens responsible for CAP, and trends in resistance, new diagnostic technologies, and newer antimicrobials approved for the treatment of CAP. These new data and additional guidelines pertaining to the treatment of CAP further our knowledge and understanding of this challenging infection. Furthermore, appreciation of the availability of new diagnostic testing and therapeutic options will help meet the demand for improved management of CAP.

Randomized phase 2 trial to evaluate the clinical efficacy of two high-dosage tigecycline regimens versus imipenem-cilastatin for treatment of hospital-acquired pneumonia

In a previous phase 3 study, the cure rates that occurred in patients with hospital-acquired pneumonia treated with tigecycline at the approved dose were lower than those seen with patients treated with imipenem and cilastatin (imipenem/cilastatin). We hypothesized that a higher dose of tigecycline is necessary in patients with hospital-acquired pneumonia. This phase 2 study compared the safety and efficacy of two higher doses of tigecycline with imipenem/cilastatin in subjects with hospital-acquired pneumonia. Subjects with hospital-acquired pneumonia were randomized to receive one of two doses of tigecycline (150 mg followed by 75 mg every 12 h or 200 mg followed by 100 mg every 12 h) or 1 g of imipenem/cilastatin every 8 h. Empirical adjunctive therapy was administered for initial coverage of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa infection, depending on the randomization regimen. Clinical response, defined as cure, failure of treatment, or indeterminate outcome, was assessed 10 to 21 days after the last day of therapy. In the clinically evaluable population, clinical cure with tigecycline 100 mg (17/20, 85.0%) was numerically higher than with tigecycline 75 mg (16/23, 69.6%) and imipenem/cilastatin (18/24, 75.0%). No new safety signals with the high-dose tigecycline were identified. A numerically higher clinical response was observed with the 100-mg dose of tigecycline. This supports our hypothesis that a higher area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC ratio) may be necessary to achieve clinical cure in patients with hospital-acquired pneumonia. Further studies are necessary. (The ClinicalTrials.gov identifier for this clinical trial is NCT00707239.).

Tigecycline: an update

Tigecycline is a broad-spectrum antibiotic with activity against difficult-to-treat pathogens such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp., Acinetobacter baumannii, and Gram-negative bacterial strains that produce extended-spectrum β-lactamases. Minimal organ toxicity and lack of dosage adjustment in most patients are important considerations for tigecycline use. Tigecycline has been shown to be as effective and safe as standard antimicrobial therapy for treatment of adults with complicated intra-abdominal infections, complicated skin and skin structure infections, and community-acquired bacterial pneumonia. The clearest applications of tigecycline are for on-label indications. Whether tigecycline should be utilized as therapy for other infections including hospital-acquired infections with a high likelihood of multidrug-resistant pathogens is a complex issue that requires ongoing assessment. This article offers an updated overview of tigecycline clinical studies, current microbial resistance patterns, pharmacokinetic/pharmacodynamic investigations, and safety analyses.

An update for community-acquired bacterial pneumonia pharmacotherapy: what's new and where does it fit?

In 2007, 1.2 million people in the United States were hospitalized with pneumonia, and more than 52 000 died from the disease. Community-acquired bacterial pneumonia (CABP) can be caused by a variety of organisms as a result of patient factors such as comorbidities, epidemiologic conditions, or the setting in which the infection was contracted. Treatment of CABP differs depending on the types of bacteria that are suspected. In the last several years, due to the concern regarding multidrug-resistant organisms (MDROs), 2 new antibiotics have been developed and approved for use in CABP. Ceftaroline fosamil (Teflaro) was approved by the US Food and Drug Administration (FDA) in October 2010 and tigecycline (Tygacil) in March 2009. In clinical trials, both agents have been shown to be efficacious and are generally well tolerated. Although these agents have received approval as therapy for CABP, it is the responsibility of physicians and pharmacists to prudently use these antimicrobials where they are truly needed. Until these agents show superiority over conventional therapy for selected patient populations, given the wide variety of pharmacotherapy that can prove efficacious for pneumonia, the new agents should be reserved for patients who have known risk factors for MDROs. Further studies are warranted for these agents in the setting of CABP.

Therapy of 1,025 severely ill patients with complicated infections in a German multicenter study: safety profile and efficacy of tigecycline in different treatment modalities

This large prospective non-interventional study investigated the effects of tigecycline either as single agent or in combination with other antimicrobial agents in 1,025 patients treated in clinical routine at German hospitals. Sixty-five percent of the patients had APACHE II scores > 15, indicating high overall disease severity. Complicated intra-abdominal infections (cIAI) or complicated skin and skin tissue infections (cSSTI) were the most common indications, with Staphylococcus aureus, Enterococcus faecium and Escherichia coli being the most frequently isolated pathogens. Clinical success was reported at the end of tigecycline therapy in 74.2% of the total population, in 75.4% of the cIAI and in 82.2% of the cSSTI patients. The subpopulation (28.0% of the patients) infected with multidrug-resistant pathogens (methicillin-resistant S. aureus, extended-spectrum β-lactamase producers and vancomycin-resistant enterococci) were treated with similar success rates as the overall population. Tigecycline was generally well tolerated. Drug-related adverse events (AEs) were reported in 7.7% of the total population; 2.5% had serious AEs mostly attributable to inefficacy of therapy or deterioration of the disease. Mortality rates were consistent with the types of infection and severity of illness. There was no indication of excessive mortality associated with tigecycline as had been suggested in previously performed meta-analyses. In this large non-interventional study performed in the clinical routine setting, tigecycline achieved favorable clinical success rates in a patient population with high severity of illness and a high prevalence of multidrug-resistant pathogens and showed a good safety and tolerability profile.

Progress on developing endpoints for registrational clinical trials of community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections: update from the Biomarkers Consortium of the Foundation for the National Institutes of Health

Efficacy endpoints for previous registrational trials of antimicrobials for acute bacterial skin and skin structure infections (ABSSSIs) and community-acquired bacterial pneumonia (CABP) were based on nonstandardized, clinician-based observations and decisions, as well as on patient reports. More quantifiable, reproducible, and externally verifiable endpoints could improve the design of future noninferiority trials. At the request of the Food and Drug Administration, the Foundation for the National Institutes of Health convened a broadly representative scientific project team to evaluate potential endpoints for such registrational trials. Review of historical and modern data led to the conclusion that antimicrobial treatment effects are most apparent early in therapy; later outcomes provide important supportive information. Although evidence is incomplete, early response endpoints can anchor noninferiority hypotheses in ABSSSI and CABP registrational trials, thereby allowing evidence-based drug development to continue. Further research is underway to establish which short- and long-term outcomes are well-defined, reliable, and reflective of how patients feel, function, or survive.

Ceftaroline fosamil in the treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections

Ceftaroline fosamil is a cephalosporin antibacterial approved by the US Food and Drug Administration (FDA) for use in the treatment of acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP). After intravenous administration, ceftaroline fosamil is rapidly converted to its bioactive metabolite, ceftaroline. Ceftaroline has broad-spectrum in vitro activity against Gram-positive and Gram-negative bacteria, including contemporary resistant Gram-positive phenotypes, such as methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Streptococcus pneumoniae. Because of its unique spectrum of activity, the Clinical and Laboratory Standards Institute (CLSI) designated ceftaroline as a member of a new subclass of β-lactam antimicrobials, cephalosporins with anti-MRSA activity. The activity of ceftaroline against S. aureus extends to heteroresistant vancomycin-intermediate, vancomycin-intermediate, vancomycin-resistant and daptomycin-nonsusceptible isolates. Ceftaroline has low minimum inhibitory concentrations (MICs) for all tested species of streptococci, and has potent activity against S. pneumoniae isolates with varying degrees of penicillin resistance. The activity of ceftaroline is limited against Enterococcus faecalis and Enterococcus faecium and against anaerobes such as Bacteroides fragilis. The in vitro activity of ceftaroline includes many Gram-negative pathogens, but does not extend to bacteria that produce extended-spectrum β-lactamases, class B metallo-β-lactamases or AmpC cephalosporinases, or to most nonfermentative Gram-negative bacilli. Ceftaroline fosamil has been studied for the treatment of complicated skin and skin structure infections (cSSSI) and community-acquired pneumonia (CAP) in phase III randomized, double-blind, international, multicentre noninferiority clinical trials. Two identical trials (CANVAS 1 and CANVAS 2) compared the efficacy of ceftaroline fosamil with that of vancomycin plus aztreonam in 1378 adults with cSSSI. Results demonstrated that ceftaroline was noninferior to vancomycin plus aztreonam, with 91.6% in the ceftaroline fosamil group (pooled analysis) achieving clinical response compared with 92.7% in the vancomycin plus aztreonam group (difference -1.1%, 95% CI -4.2, 2.0). An additional analysis evaluated clinical cure in a subgroup of patients who met the FDA guidance definition of ABSSSI at treatment day 3. Clinical response, defined as cessation of lesion spread and absence of fever, was 74.0% in the ceftaroline fosamil group compared with 66.2% in the vancomycin plus aztreonam group (treatment difference 7.8%, 95% CI 1.3, 14.0). Clinical efficacy of ceftaroline fosamil in 1240 hospitalized adults with CAP was compared with that of ceftriaxone in two additional phase III trials (FOCUS 1 and FOCUS 2). Of note, because ceftriaxone does not have activity against MRSA, patients with confirmed or suspected MRSA CAP were excluded from the FOCUS trials. Results demonstrated that ceftaroline was noninferior to ceftriaxone, with 84.3% in the ceftaroline fosamil group achieving clinical cure compared with 77.7% in the ceftriaxone group (difference 6.7%, 95% CI 1.6, 11.8). An additional analysis of the trials was conducted in patients with moderate to severe CAP and at least one proven typical bacterial pathogen at baseline (i.e. CABP). Day 4 clinical response rates were 69.5% for ceftaroline and 59.4% for ceftriaxone (difference 10.1%, 95% CI -0.6, 20.6). In the phase III trials, adverse event rates were similar between groups. Overall, ceftaroline is well tolerated, which is consistent with the good safety and tolerability profile of the cephalosporin class. In summary, ceftaroline fosamil is a broad-spectrum parenteral cephalosporin with excellent in vitro activity against resistant Gram-positive pathogens, including MRSA, as well as many common Gram-negative organisms. It is a welcome treatment option for ABSSSI and CABP.

Switch therapy in hospitalized patients with community-acquired pneumonia: tigecycline vs. levofloxacin

Background

Switch therapy is a management approach combining early discontinuation of intravenous (IV) antibiotics, switch to oral antibiotics, and early hospital discharge. This analysis compares switch therapy using tigecycline versus levofloxacin in hospitalized patients with community-acquired pneumonia (CAP).

Methods

A prospective, randomized, double-blind, Phase 3 clinical trial; patients were randomized to IV tigecycline (100 mg, then 50 mg q12h) or IV levofloxacin (500 mg q24h). Objective criteria were used to define time to switch therapy; patients were switched to oral levofloxacin after ≥6 IV doses if criteria met. Switch therapy outcomes were assessed within the clinically evaluable (CE) population.

Results

In the CE population, 138 patients were treated with IV tigecycline and 156 were treated with IV levofloxacin. The proportion of the population that met switch therapy criteria was 67.4% (93/138) for tigecycline and 66.7% (104/156) for levofloxacin. The proportion that actually switched to oral therapy was 89.9% (124/138) for tigecycline and 87.8% (137/156) for levofloxacin. Median time to actual switch therapy was 5.0 days each for tigecycline and levofloxacin. Clinical cure rates for patients who switched were 96.8% for tigecycline and 95.6% for levofloxacin. Corresponding cure rates for those that met switch criteria were 95.7% for tigecycline and 92.3% for levofloxacin.

Conclusions

Switch therapy outcomes in hospitalized patients with CAP receiving initial IV therapy with tigecycline are comparable to those of patients receiving initial IV therapy with levofloxacin. These data support the use of IV tigecycline in hospitalized patients with CAP when the switch therapy approach is considered.

ClinicalTrials.gov Identifier

NCT00081575

Pharmacokinetics and safety profile of tigecycline in children aged 8 to 11 years with selected serious infections: a multicenter, open-label, ascending-dose study

BACKGROUND

Tigecycline, a broad-spectrum antibiotic used for treating serious bacterial infections in adults, may be suitable for pediatric use once an appropriate dosage is determined.

OBJECTIVE

The aim of this study was to assess the pharmacokinetic (PK) properties, safety profile, and descriptive efficacy of tigecycline.

METHODS

In this Phase II, multicenter, open-label clinical trial, children aged 8 to 11 years with community-acquired pneumonia (CAP), complicated intra-abdominal infection (cIAI), or complicated skin and skin structure infections (cSSSI) were administered tigecycline 0.75, 1, or 1.25 mg/kg.

RESULTS

A total of 58 patients received ≥ 1 dose of tigecycline (31 boys; 44 white; mean age, 10 years; mean weight, 35 kg); 47 had data from samples available for PK analysis. The mean (SD) PK values were: C(max), 1899 (2954) ng/mL; T(max), 0.56 (0.18) hour; between-dose AUC, 2833 (1557) ng · h/mL; weight-normalized clearance, 0.503 (0.293) L/h/kg; and Vd(ss), 4.88 (4.84) L/kg. Overall clinical cure rates at test-of-cure were 94% (16/17), 76% (16/21), and 75% (15/20) in the 0.75-, 1-, and 1.25-mg/kg cohorts, respectively. The rates of protocol violations were higher in the 1- and 1.25-mg/kg groups, resulting in higher proportions of indeterminate clinical cure assessments relative to the 0.75-mg/kg cohort (19% and 15% vs 0%). The most frequent adverse event was nausea, which occurred in 50% of patients overall (29/58) and the prevalence of which was significantly higher in the 1.25-mg/kg group versus the 0.75-mg/kg group (65% vs 18%; P = 0.007). Pharmacodynamic simulations using MIC data from an ongoing microbiological surveillance trial predicted that a dosage of 1.2 mg/kg q12h would lead to therapeutic target attainment levels of up to 82% for the target AUC(0-24)/MIC ratios.

CONCLUSION

A tigecycline dosage of ∼1.2 mg/kg q12h may represent the most appropriate dosage for subsequent evaluation in Phase III clinical trials in children aged 8 to 11 years with selected serious bacterial infections. ClinicalTrials.gov identifier: NCT00488345.