Tigecycline and the Need for a New Broad-Spectrum Antibiotic Class

A pharmacovigilance study of the association between tetracyclines and hepatotoxicity based on Food and Drug Administration adverse event reporting system data

Background While tetracycline antibiotics are commonly prescribed in practice, the risk of drug-induced liver injury (DILI) remains controversial. Aim To evaluate the association of DILI with tetracycline antibiotics. Method All DILI cases of tetracycline antibiotics as primary suspected drugs were extracted from the US Food and Drug Administration adverse event reporting system (FAERS). The outcomes included severe DILI, hepatocellular injury, cholestatic injury, and liver failure. Disproportionality analyses were conducted by estimating the reporting odds ratio (ROR) and the information component (IC). Results A total of 1,435 liver injury cases associated with tetracycline antibiotics were identified. The DILI signal was detected in tigecycline, minocycline, and doxycycline. The RORs and the 95% confidence intervals (95% CI) of tigecycline, minocycline, and doxycycline were (ROR 5.85, 95% CI 4.96-6.91), (ROR 6.4, 95% CI 5.76-7.11), and (ROR 2.07, 95% CI 1.86-2.31), respectively. Compared to minocycline (ROR 5.5, 95% CI 4.94-6.12; IC 2.35, 95% CI 1.98-2.68) and doxycycline (ROR 1.91, 95% CI 1.71-2.12; IC 0.91, 95% CI 0.55-1.26), tigecycline showed a stronger association with hepatocellular injury (ROR 7.11, 95% CI 6.13-8.23; IC 2.68, 95% CI 2.16-3.13). Tigecycline also showed a stronger association with cholestatic injury (ROR 12.16, 95% CI 10.13-14.61; IC 3.51, 95% CI 2.79-4) than minocycline (ROR 3.23, 95% CI 2.59-4.04; IC 1.67, 95% CI 0.9-2.37) or doxycycline (ROR 2.86, 95% CI 2.47-3.31; IC 1.5, 95% CI 1-1.97). Tigecycline (ROR 6.56, 95% CI 4.57-9.41; IC 2.69, 95% CI 1.28-3.64) and minocycline (ROR 4.22, 95% CI 3.14-5.66; IC 2.06, 95% CI 1-2.93) showed a significant association with liver failure. Conclusion The data mining of FAERS suggested an association between DILI and tigecycline, minocycline, and doxycycline.

Calculated parenteral initial treatment of bacterial infections: Introduction and antibiotics

This is the first chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. This guideline is a revision of the recommendations published in 2010, taking into account recent substances and studies. As with previous revisions, the current situation of pathogen resistance and the results of new clinical trials are considered. The results are the present recommendations for parenteral calculated initial therapy of bacterial infections in adults. If several treatment options are mentioned, they are not always equivalent in their spectrum of microbiological activity. Therapeutic alternatives offer the opportunity to consider pathogen epidemiology, to avoid antibiotic intolerances or to escalate or de-escalate treatment in a manner suited to the situation. This article describes the different therapy options.

Comparison of the pharmacokinetic properties of vancomycin, linezolid, tigecyclin, and daptomycin

The rapid antibiotic resistance development has created a major demand for new antimicrobial agents that can combat resistant strains such as methicillin-resistant S. aureus (MRSA). Until a short time ago, the glycopeptide vancomycin was the only therapeutic choice in this situation. However, in recent years some newer agents with different mechanisms of actions have been added to the arsenal, and more are on the horizon. For a successful therapy it is of vital importance that these compounds are used judiciously and dosed appropriately. The present article reviews the pharmacokinetic properties of vancomycin, linezolid, tigecycline and daptomycin. The first major difference between these compounds is their oral bioavailability. Only linezolid can be administered orally, whereas vancomycin, daptomycin and tigecycline are limited to parenteral use. Once in the body, they show very different disposition. Daptomycin has a very small volume of distribution of 7L indicating very little tissue distribution whereas tigecycline has a very large volume of distribution of 350-500 L. Vancomycin and linezolid are in-between with volumes of distribution of approximately 30 and 50 L, close to total body water. However, studies have shown that linezolid shows better tissue penetration than vancomycin. Newer studies using microdialysis, a new technique that allows direct monitoring of unbound tissue levels, support this finding. As far as drug elimination, daptomycin and vancomycin are mainly eliminated into the urine and require dosing adjustments in renally impaired patients, whereas tigecycline is eliminated into the bile and linezolid is metabolized so that in renal patients no dosing adjustments are needed for these compounds. Although the elimination pathways are very different, the resulting half-lives of linezolid, vancomycin, and daptomycin are not greatly different and vary from 4-8 h. Tigecycline, however, has a much longer half-life of up to 1-2 days due to the slow redistribution from tissue binding sites.

Treatment of complicated skin and soft-tissue infections caused by resistant bacteria: value of linezolid, tigecycline, daptomycin and vancomycin

Antibiotic-resistant organisms causing both hospital- and community-acquired complicated skin and soft-tissue infections (cSSTI) are increasingly reported. A substantial medical and economical burden associated with MRSA colonisation or infection has been documented. The number of currently available appropriate antimicrobial agents is limited. Good quality randomised, controlled clinical trial data on antibiotic efficacy and safety is available for cSSTI caused by MRSA. Linezolid, tigecycline, daptomycin and vancomycin showed efficacy and safety in MRSA-caused cSSTI. None of these drugs showed significant superiority in terms of clinical cure and eradication rates.To date, linezolid offers by far the greatest number of patients included in controlled trials with a strong tendency of superiority over vancomycin in terms of eradication and clinical success.. - Tigecycline is an alternative in polymicrobial infections except by diabetic foot infections. Daptomycin might be a treatment option for cases of cSSTI with MRSA bacteremia. cSSTI caused by resistant Gram-negative bacteria are a matter of great concern. The development of new antibiotics in this area is an urgent priority to avoid the risk of a postantibiotic era with no antimicrobial treatment options. An individual approach for every single patient is mandatory to evaluate the optimal antimicrobial treatment regimen.

Management of complicated infections in the era of antimicrobial resistance: the role of tigecycline

BACKGROUND

Increasing antimicrobial resistance and infection complications pose challenges to optimal antibiotic therapy. Paucity of new antibiotics (and the eventual bacterial resistance they face) highlights the critical need for more appropriate use of broadly effective agents, which may help to thwart the dramatic rise in global resistance. Single agents that can be combined effectively with others, if needed, promise the simplest overall utility. Approved in 2005 to treat complicated skin and intra-abdominal infections, tigecycline is a novel extended-spectrum minocycline derivative that circumvents bacterial resistance, as it is unaffected by efflux pumps and ribosomal protection. However, tigecycline should not be used as empiric monotherapy for treatment of health-care associated infections known or suspected to be owing to Pseudomonas aeruginosa or Proteus spp.

OBJECTIVE

This article summarizes the demonstrated clinical utility of tigecycline so far.

METHODS

A MEDLINE search examined authoritative published clinical studies, reviews and case reports detailing the clinical record of tigecycline since 2004.

RESULTS/CONCLUSION

Tigecycline continues to maintain satisfactory profiles of safety, efficacy and antimicrobial resistance avoidance. Regardless, continued surveillance is needed to detect reduced susceptibility and resistance against both community and nosocomial pathogens. Judicious use of agents reserved for multidrug resistant pathogens is vital to preserve their effectiveness.

Tigecycline use in cancer patients with serious infections: a report on 110 cases from a single institution

Tigecycline, the first in a new class of glycylcyclines, has been approved for the treatment of complicated skin and skin structure and intraabdominal infections in adults. However, clinical data on its safety and effectiveness in cancer patients are lacking. We reviewed the records of all cancer patients treated with tigecycline for more than 48 hours between June 2005 and September 2006 at our institution and identified 110 consecutive cases (median age, 58 yr; range, 18-81 yr). We collected data on demographics, cancer type, tigecycline indication, microbiologic characteristics, side effects, and outcome. Sixty-four (58%) patients had hematologic malignancies; 27 patients had undergone hematopoietic stem cell transplantation. Thirty-one (28%) patients had neutropenia, and 62 (56%) were in the intensive care unit at the start of therapy. Most patients (106 [96%]) received tigecycline as a second-line agent (after not responding to other broad-spectrum antibiotics), and 101 (92%) received it in combination with an antipseudomonal drug. The mean duration of therapy was 11 days (range, 3-35 d). Sixty-six (60%) patients received tigecycline for refractory pneumonia, 19 (17%) had bacteremia, 9 (8%) had intraabdominal infections, and 7 (6%) had complicated skin and soft tissue infections. Fifty (45%) patients had microbiologically documented infections, and the remaining patients had negative cultures at the start of therapy.An overall clinical response was noted in 70 (64%) patients. More clinical responses were seen in patients with bacteremia than in those with pneumonia (79% vs. 51%; p = 0.029). Patients with microbiologically documented infections had significantly higher clinical response rates than patients with non-microbiologically documented infections (73% vs. 55%; p = 0.047). Forty (36%) patients did not respond to treatment; 36 of these patients died of active infection during tigecycline therapy. Patients with pneumonia had a significantly higher mortality rate than patients with bacteremia (44% vs. 16%; p = 0.026). During the 60 days of follow-up from the date of clinical response, patients with pneumonia had significantly shorter survival durations than patients with other infections. Of the 42 patients who were not on antiemetics or ventilator support at the start of tigecycline therapy, 2 (5%) experienced mild nausea, and 1 (2%) experienced nausea and vomiting. Only 4 (4%) patients overall experienced diarrhea during tigecycline therapy, all of whose stools were negative for Clostridium difficile toxin. No serious adverse events related to tigecycline use were identified. The combination of tigecycline and an antipseudomonal drug may be appropriate for treating refractory infections and multidrug-resistant organisms in cancer patients, including hematopoietic stem cell transplant recipients. Patients with refractory pneumonia had a relatively low clinical response rate in our study.

Antimicrobial therapy of multidrug-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci, and methicillin-resistant Staphylococcus aureus

Antibiotic resistance among pneumococci, enterococci, and staphylococci has become increasingly important in recent decades. Clinicians should be familiar with the nuances of antibiotic susceptibility testing and interpretation in selecting antibiotics for these infections. The clinical significance of penicillin-resistant Streptococcus pneumoniae, macrolide-resistant S pneumoniae, and multidrug-resistant S pneumoniae is discussed. The clinical spectrum and therapeutic approach to Enterococcus faecalis (i.e., vancomycin-sensitive enterococci) and E faecium (i.e., vancomycin-resistant enterococci) are discussed. Differences in therapeutic approach between methicillin-sensitive Staphylococcus aureus and methicillin-resistant S aureus (MRSA) infections are reviewed. Differences between in vitro susceptibility testing and in vivo effectiveness of antibiotics for hospital-acquired MRSA (HA-MRSA) are described. Finally, the clinical features of infection and therapy of HA-MRSA and community-acquired MRSA (CA-MRSA) infections are compared.