Oral antibiotic therapy for the treatment of infective endocarditis: a systematic review

Development and in vitro-in vivo evaluation of ocular insert containing ketorolac tromethamine and moxifloxacin hydrochloride

PURPOSE

Conjunctivitis is a common eye disorder that causes swelling and inflammation of the conjunctiva. Topical dosage form containing antibiotics and non-steroidal anti-inflammatory drugs are prescribed for the treatment and in order to overcome problems of conventional dosage forms the present study aims to develop an ocular insert containing moxifloxacin HCl and ketorolac tromethamine.

METHODS

Insert was prepared by a solvent casting method by taking different polymers PVA, PVP K-30, and a combination of both as film-forming polymer, and glycerol as a plasticizer and characterized by various parameters like thickness, folding endurance, pH, swelling index, drug content, mechanical properties, in vitro and in vivo release study.

RESULTS

The formulation prepared by a combination of both polymers demonstrated significantly improved properties including % elongation, tensile strength, swelling index, drug content and drug release compared to the formulation made with single polymer. The in vitro release data indicated that the batch R8 exhibited sustain release of drug (85% release in 10 hr) and following the Higuchi model for release kinetics. In vivo, study in rabbit eyes revealed the sustained release of the drug up to 16 hr with a good correlation between in vitro and in vivo release data.

CONCLUSION

From the study, it can be concluded that the developed ocular insert can be a promising formulation for rational therapy of conjunctivitis.

Partial oral versus full intravenous antibiotic treatment of endocarditis in people who inject drugs: A systematic review

Background

Prolonged intravenous (IV) antibiotic therapy may not be optimal for people who inject drugs (PWID) with infective endocarditis (IE) due to unique social and medical needs. The role of partial IV antibiotic therapy with continued oral (PO) antibiotic therapy is unclear.

Methods

A systematic review was performed using EMBASE and MEDLINE databases. Included studies compared PO to IV antibiotic treatment for IE in PWID.

Results

Four studies met eligibility. Observational studies included full IV treatment groups and partial IV, partial PO treatment groups for severe injection-related infections. PWID with IE comprised 41.0%-64.7% of the study populations but outcomes specific to IE were not separately reported. All-cause 90-day readmission rates were comparable between the IV treatment group (27.9%-31.5%) and partial IV, partial PO treatment group (24.8%-32.5%). Ninety-day mortality was non-significantly different between IV treatment (4.9%-10.7%) and partial IV, partial PO treatment groups (2.4%-13.0%). One small randomized clinical trial compared IV oxacillin or vancomycin with gentamicin to PO ciprofloxacin plus rifampin. The cure rates were 91% and 90%, respectively.

Conclusion

There is limited evidence comparing IV treatment to partial IV, partial PO antibiotic treatment in PWID with IE. Observational studies suggest that PO antibiotic therapy after initial IV treatment may be equivalent to full IV treatment alone within specific parameters, but randomized trials are needed to inform recommendations. Substantial clinical and social benefits for PWID and advantages for the health care system will result if PO treatment strategies with equal efficacy can be implemented.

Successful Treatment of Infective Endocarditis With Oral Antibiotics: A Case Report

Infective endocarditis (IE) is a serious and potentially life-threatening infection of the heart valves. It is commonly treated with prolonged courses of intravenous antibiotics, and in some cases, surgical intervention may also be necessary. While the use of oral antibiotics in the treatment of IE is generally limited, there are select cases where they may be considered as an alternative treatment option. Here, we report a case of staphylococcal right-sided IE successfully treated with oral antibiotics (linezolid and rifampicin). Our case highlights the potential for oral antibiotics to be used as step-down therapy for select patients with IE.

Infective Endocarditis: Still More Challenges Than Convictions

After fourteen decades of medical and technological evolution, infective endocarditis continues to challenge physicians in its daily diagnosis and management. Its increasing incidence, demographic shifts (affecting older patients), microbiology with higher rates of Staphylococcus infection, still frequent serious complications and substantial mortality make endocarditis a very complex disease. Despite this, innovations in the diagnosis, involving microbiology and imaging, and improvements in intensive care and cardiac surgical techniques, materials and timing can impact the prognosis of this disease. Ongoing challenges persist, including rethinking prophylaxis, improving the diagnosis criteria comprising blood culture-negative endocarditis and prosthetic valve endocarditis, timing of surgical intervention, and whether to perform surgery in the presence of ischemic stroke or in intravenous drug users. A combined strategy on infective endocarditis is crucial, involving advanced clinical decisions and protocols, a multidisciplinary approach, national healthcare organization and health policies to achieve better results for our patients.

Streptococcal and enterococcal endocarditis: time for individualized antibiotherapy?

Recommendations for the treatment of streptococcal and enterococcal endocarditis are based on old efficacy studies, but the starting doses have never been reassessed and are associated with significant adverse events. Based on data from other serious infections, we suggest that maintaining a concentration of β-lactams higher than 4-6 times the responsible bacteria MIC 100% of the time in the heart of the vegetation would be a pertinent therapeutic objective. The data point to a diffusion gradient of β-lactams in the vegetation. Yet, so far as is known, the ratio of antibiotic concentration at steady state between plasma and vegetation cannot be completely determined. Answering this crucial question would make it possible for each patient to have a targeted β-lactam plasma concentration, according to the MIC for the responsible bacteria. This would lead the way to personalized antibiotherapy and allow a safe switch to oral medication.

Oral antibiotics for infective endocarditis: a clinical review

Current guidelines for management of infective endocarditis (IE) advise 4-6 weeks of IV antibiotics. This is based on historical data from animal models, which set a precedent for high peak serum antimicrobial levels, thought to be only achievable with IV therapy. However, there has been increasing recent interest in oral antibiotics as an alternative to prolonged parenteral therapy, not limited to treatment of IE. This review examines the theory behind parenteral antibiotic administration with reference to the MICs of relevant pathogens. By comparing published serum antimicrobial levels after oral and IV administration we suggest that safe levels of commonly used antibiotics can be achieved orally. We have then reviewed the literature to date on oral antibiotics for IE. The largest randomized controlled trial (RCT) in this area, the POET trial, concluded that oral therapy was non-inferior to prolonged IV therapy in stable patients with left-sided IE. Additionally, there have been two smaller RCTs published, as well as a number of observational studies over the last 50 years, utilizing a variety of different patient groups, methods and treatment strategies. This body of evidence gives weight to a potential shift in practice towards oral therapy, primarily as a step-down treatment. We conclude that pharmacological data offer theoretical reassurance for the safety of oral therapy. This is coupled with a growing evidence base for non-inferiority of oral antimicrobials compared with prolonged parenteral therapy in practice.

Long-term antibiotic therapy in patients with surgery-indicated not undergoing surgery infective endocarditis

BACKGROUND

To date, there is little information regarding management of patients with infective endocarditis (IE) that did not undergo an indicated surgery. Therefore, we aimed to evaluate prognosis of these patients treated with a long-term antibiotic treatment strategy, including oral long term suppressive antibiotic treatment in five referral centres with a multidisciplinary endocarditis team.

METHODS

This retrospective, multicenter study retrieved individual patient-level data from five referral centres in Spain. Among a total of 1797, 32 consecutive patients with IE were examined (median age 72 years; 78% males) who had not undergone an indicated surgery, but received long-term antibiotic treatment (LTAT) and were followed by a multidisciplinary endocarditis team, between 2011 and 2019. Primary outcomes were infection relapse and mortality during follow-up.

RESULTS

Among 32 patients, 21 had IE associated with prostheses. Of the latter, 8 had an ascending aorta prosthetic graft. In 24 patients, a switch to long-term oral suppressive antibiotic treatment (LOSAT) was considered. The median duration of LOSAT was 277 days. Four patients experienced a relapse during follow-up. One patient died within 60 days, and 12 patients died between 60 days and 3 years. However, only 4 deaths were related to IE.

CONCLUSIONS

The present study results suggest that a LTAT strategy, including LOSAT, might be considered for patients with IE that cannot undergo an indicated surgery. After hospitalization, they should be followed by a multidisciplinary endocarditis team.

Structural insights into the inhibition of bacterial RecA by naphthalene polysulfonated compounds

As a promising target for alternative antimicrobials, bacterial recombinase A (RecA) protein has attracted much attention for its roles in antibiotic-driven SOS response and mutagenesis. Naphthalene polysulfonated compounds (NPS) such as suramin have previously been explored as antibiotic adjuvants targeting RecA, although the underlying structural bases for RecA-ligand interactions remain obscure. Based on our in silico predictions and documented activity of NPS in vitro, we conclude that the analyzed NPS likely interact with Tyr103 (Y103) and other key residues in the ATPase activity center (pocket A). For validation, we generated recombinant RecA proteins (wild-type versus Y103 mutant) to determine the binding affinities for RecA protein interactions with suramin and underexamined NPS in isothermal titration calorimetry. The corresponding dissociation constants (K d) ranged from 11.5 to 18.8 μM, and Y103 was experimentally shown to be critical to RecA-NPS interactions.

The Effect of Adjunctive Antibiotic Oral Therapy on the Recurrence of Infective Endocarditis After Valve Surgeries

Adjunctive oral antibiotics following intravenous antibiotics are administered after valve surgery in some patients with active infective endocarditis (IE); however, little is known about their efficacy. Therefore, we evaluated the effect of adjunctive antibiotic oral therapy after IE surgeries. Between 2009 and 2017, 585 patients underwent valve surgery for left-sided active IE at 14 hospitals. Patients who died during hospitalization or transferred with intravenous antibiotics were excluded. Of the remaining 460 patients, 239 were treated with oral antibiotics at discharge (group O) and 221 did not take the oral antibiotic (group N). The primary outcome was all-cause mortality. Secondary outcomes were the recurrence of IE and a subset analysis of it. The 2 groups had similar background, postoperative inflammatory responses, and an almost similar duration of postoperative intravenous antibiotics. The overall survival rates at 1 and 5 years were 96% and 88% in group O and 92% and 84% in group N, respectively (P = 0.425). The rates of freedom from the recurrence of endocarditis at 1 and 5 years were 98% and 94% in group O and 97% and 93% in group N, respectively (P = 0.309). In chronic hemodialysis patients, the rates of freedom from the recurrence were significantly higher in group O than in group N (1 year: 100% vs 87.5%; 5 years: 95% vs 69%, P = 0.022). Adjunctive oral antibiotics following intravenous antibiotics in patients with active IE after valve surgery did not affect the overall survival and recurrence of IE, except in chronic hemodialysis patients.

Retrospective analysis of endocarditis patients to investigate the eligibility for oral antibiotic treatment in routine daily practice

Background

According to the current guidelines of the European Society of Cardiology, patients with left-sided infective endocarditis are treated with intravenous antibiotics for 4–6 weeks, leading to extensive hospital stay and high costs. Recently, the Partial Oral Treatment of Endocarditis (POET) trial suggested that partial oral treatment is effective and safe in selected patients. Here, we investigated if such patients are seen in our daily clinical practice.

Methods

We enrolled 119 adult patients diagnosed with left-sided infective endocarditis in a retrospective, observational study. We identified those that would be eligible for switching to partial oral antibiotic treatment as defined in the POET trial (e.g. stable clinical condition without signs of infection). Secondary objectives were to provide insight into the time until each patient was eligible for partial oral treatment, and to determine parameters of longer hospital stay and/or need for extended intravenous antibiotic treatment.

Results

Applying the POET selection criteria, the condition of 38 patients (32%) was stable enough to switch them to partial oral treatment, of which 18 (47.3%), 8 (21.1%), 9 (23.7%) and 3 patients (7.9%) were eligible for switching after 10, 14, 21 days or 28 days of intravenous treatment, respectively.

Conclusion

One-third of patients who presented with left-sided endocarditis in routine clinical practice were possible candidates for switching to partial oral treatment. This could have major implications for both the patient’s quality of life and healthcare costs. These results offer an interesting perspective for implementation of such a strategy, which should be accompanied by a prospective cost-effectiveness analysis.

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01490-2) contains supplementary material, which is available to authorized users.

A review of current treatment strategies for infective endocarditis

INTRODUCTION

Infective endocarditis is one of the most difficult-to-treat infectious diseases.

AREAS COVERED

We restricted this review to the anti-infective treatment of the main bacteria responsible for infective endocarditis, i.e. staphylococci, streptococci, enterococci, and Gram-negative bacilli, including HACEK. Specific topics of major interest in treatment strategy are covered as well, including empirical treatment, oral switch, and treatment duration. We searched in the MEDLINE database to identify relevant studies, trials, reviews, or meta-analyses until May 2020.

EXPERT OPINION

The use of aminoglycosides for the treatment of endocarditis has been dramatically reduced over the last 20 years. It should be administered once daily, and no longer than 2 weeks. For staphylococcal endocarditis, recent data reinforced the role of anti-staphylococcal penicillins, for methicillin-susceptible isolates (alternative, cefazolin), and vancomycin for methicillin-resistant isolates (alternative, daptomycin). For staphylococcal prosthetic-valve endocarditis, these treatments will be reinforced by the addition of gentamicin during the first 2 weeks, and rifampin throughout the whole treatment duration, i.e. 6 weeks. The optimal duration of antibacterial treatment is 4 weeks for most native valve endocarditis, and 6 weeks for prosthetic-valve endocarditis. The oral switch is safe in patients stabilized after the initial intravenous course.

Infective Endocarditis in Persons Who Use Drugs: Epidemiology, Current Management, and Emerging Treatments

Infective endocarditis associated with injection drug use (IDU-IE) is markedly increasing in the United States and Canada. Long-term outcomes are dismal and stem from insufficient substance use disorder treatment. In this review, we summarize the principles of antimicrobial and surgical management for infective endocarditis associated with injection drug use. We discuss approaches to opioid use disorder care and harm reduction in the inpatient setting and review opportunities to address preventable infections among persons injecting drugs. We highlight barriers to implementing optimal treatment and consider novel approaches that may reshape infective endocarditis associated with injection drug use treatment in coming years.

Oral switch versus standard intravenous antibiotic therapy in left-sided endocarditis due to susceptible staphylococci, streptococci or enterococci (RODEO): a protocol for two open-label randomised controlled trials

INTRODUCTION

Left-sided infective endocarditis (IE) is a serious infection with a heavy burden for patients and healthcare system. Oral switch after initial intravenous antibiotic therapy may reduce costs and improve patients' discomfort without increasing unfavourable outcomes. We describe the methodology of two simultaneously conducted open-label randomised trials aiming to assess non-inferiority of oral switch as compared with entirely intravenous antibiotic therapy for the treatment of left-sided IE.

METHODS AND ANALYSIS

Two simultaneous multicentre open-label prospective randomised trials assessing non-inferiority of oral switch during antibiotic treatment as compared with entirely intravenous therapy in patients with left-sided IE are ongoing. One trial is dedicated to left-sided IE caused by multisusceptible staphylococci (Relais Oral Dans le traitement des Endocardites à staphylocoques ou streptOcoques (RODEO)-1) and the other is dedicated to left-sided IE caused by susceptible streptococci or enterococci (RODEO-2). It is planned to randomise 324 patients in each trial after an initial course of at least 10 days of intravenous antibiotic therapy either to continue intravenous antibiotic therapy or to switch to oral antibiotic therapy. The primary outcome is treatment failure within 3 months after the end of antibiotic treatment, a composite outcome defined by all-cause death and/or symptomatic embolic events and/or unplanned valvular surgery and/or microbiological relapse (with the primary pathogen). Secondary outcomes include patient quality of life, echocardiographic outcome, costs and efficiency associated with IE care. Statistical analysis will be performed with a non-inferiority margin of 10% and a one-sided 2.5% type I error.

ETHICS AND DISSEMINATION

Written informed consent will be obtained from all participants. This study was approved by Tours Research ethics committee (CPP TOURS-Region Centre-Ouest 1, 2015-R26, 23 February 2016). Study findings will be published in peer-reviewed journals and disseminated through presentation at relevant national and international conferences.

TRIAL REGISTRATION NUMBER

EudraCT Number: 2015-002371-16 and NCT02701608; NCT02701595.

Evaluation of a Paradigm Shift From Intravenous Antibiotics to Oral Step-Down Therapy for the Treatment of Infective Endocarditis: A Narrative Review

IMPORTANCE

The requirement of prolonged intravenous antibiotic courses to treat infective endocarditis (IE) is a time-honored dogma of medicine. However, numerous antibiotics are now available that achieve adequate levels in the blood after oral administration to kill bacteria. Moreover, prolonged intravenous antibiotic regimens are associated with high rates of adverse events. Accordingly, recent studies of oral step-down antibiotic treatment have stimulated a reevaluation of the need for intravenous-only therapy for IE.

OBSERVATIONS

PubMed was reviewed in October 2019, with an update in February 2020, to determine whether evidence supports the notion that oral step-down antibiotic therapy for IE is associated with inferior outcomes compared with intravenous-only therapy. The search identified 21 observational studies evaluating the effectiveness of oral antibiotics for treating IE, typically after an initial course of intravenous therapy; none found such oral step-down therapy to be inferior to intravenous-only therapy. Multiple studies described an improved clinical cure rate and an improved mortality rate among patients treated with oral step-down vs intravenous-only antibiotic therapy. Three randomized clinical trials also demonstrated that oral step-down antibiotic therapy is at least as effective as intravenous-only therapy in right-sided, left-sided, or prosthetic valve IE. In the largest trial, at 3.5 years of follow-up, patients randomized to receive oral step-down antibiotic therapy had a significantly improved cure rate and mortality rate compared with those who received intravenous-only therapy.

CONCLUSIONS AND RELEVANCE

This review found ample data demonstrating the therapeutic effectiveness of oral step-down vs intravenous-only antibiotic therapy for IE, and no contrary data were identified. The use of highly orally bioavailable antibiotics as step-down therapy for IE, after clearing bacteremia and achieving clinical stability with intravenous regimens, should be incorporated into clinical practice.

Potential savings through single-dose intravenous Dalbavancin in long-term MRSA infection treatment - a health economic analysis using German DRG data

Complicated infections such as osteomyelitis, skin and soft tissue infections or endocarditis often require antibiotic therapies that can last up to several weeks. The prolonged hospital length of stay (LOS) leads to a dramatic increase in costs. Single-dose intravenous Dalbavancin is a novel antimicrobial agent for the treatment of acute bacterial skin, skin structure and soft tissue infections (ABSSSI) that allows an earlier discharge of patients, resulting in potential savings. Joint, bone and prostheses infections (JBPI) are also related with long LOS. The aim of this study is to determine the economic effects of single-dose intravenous Dalbavancin in suitable patients with Methicillin-resistant Staphylococcus aureus infections in Germany. For this purpose, an analysis with real-world patient treatment data was performed, which was subsequently validated in a large German hospital. In total, ABSSSI patients with MRSA infections could stay 6.45 days shorter and 2,865 € could be saved while JBPI patients could be discharged eventually 10.6 days earlier and 3,909 € could be saved. Single-dose intravenous Dalbavancin is thus an option for patients with ABSSSI and JBPI who are eligible for discharge.

Cefpodoxime proxetil as a therapeutic option in switching therapy for infective endocarditis in children: case reports and literature review

Infective endocarditis (IE) is uncommon in children, affecting predominantly subjects with congenital heart disease (CHD) and patients with indwelling central lines. The principles of antibiotic treatment in paediatric population are similar to those in adults. Prolonged intravenous administration of bactericidal rather than bacteriostatic agents is preferred. Outpatient intravenous therapy after initial treatment in the hospital may be considered only in selected patients. Partial oral treatment has been described in cases of left-sided, uncomplicated IE caused by common pathogens in adult patients. There are no guidelines or trials in paediatric population regarding switching therapy from intravenous to oral route. We present two cases of IE in children caused by uncommon pathogenic bacteria (Abiotrophia defectiva and Haemophilus parainfluenzae) successfully treated with oral third-generation cephalosporin - cefpodoxime proxetil after initial intravenous therapy. This paper provides observations on different therapeutic approach for IE in children as well as another potential use of cefpodoxime proxetil.

The novel use of oral antibiotic monotherapy in prosthetic valve endocarditis caused by Finegoldia magna: a case study

Background

Finegoldia magna, a Gram-positive anaerobic coccus, is part of the human normal microbiota as a commensal of mucocutaneous surfaces. However, it remains an uncommon pathogen in infective endocarditis, with only eight clinical cases previously reported in the literature.

Currently, infective endocarditis is routinely treated with prolonged intravenous antibiotic therapy. However, recent research has found that switching patients to oral antibiotics is non-inferior to prolonged parenteral antibiotic treatment, challenging the current guidelines for the treatment of infective endocarditis.

Case presentation

This case report focuses on a 52-year-old gentleman, who presented with initially culture-negative infective endocarditis following bioprosthetic aortic valve replacement. Blood cultures later grew Finegoldia magna. Following initial intravenous antibiotic therapy and re-do surgical replacement of the prosthetic aortic valve, the patient was successfully switched to oral antibiotic monotherapy, an unusual strategy in the treatment of infective endocarditis inspired by the recent publication of the POET trial. He made excellent progress on an eight-week course of oral antibiotics and was successfully discharged from surgical follow-up.

Conclusions

This case is the 9th reported case of Finegoldia magna infective endocarditis in the literature. Our case also raises the possibility of a more patient-friendly and cost-effective means of providing long-term antibiotic therapy in suitable patients with prosthetic valve endocarditis and suggests that the principles highlighted in the POET trial can also be applicable to post-operative patients after cardiac surgery.

Current Evidence on Oral Antibiotics for Infective Endocarditis: A Narrative Review

Infective endocarditis (IE) continues to be associated with high morbidity and mortality, even when treated with optimal antibiotic regimens. The selection of treatment depends on the causative pathogen, its antibiotic susceptibility profile, local and systemic complications and the presence of prosthetic materials or devices. Standard therapy typically involves 4–6 weeks of intravenous (IV) bactericidal therapy. However, there are instances in which IV antibiotic administration may be challenging due to cost, complications of IV access, adverse side-effects of the medication or concerns for misuse of the IV line. Current clinical guidance from the American Heart Association and the European Society of Cardiology cite scenarios where oral antibiotics can be considered for treatment of IE, though these situations are relatively infrequent and data to show their non-inferiority limited. Recently, a well-designed randomized clinical study reported favorable outcomes for partial oral antimicrobial therapy regimens given to patients with staphylococcal, streptococcal and enterococcal IE deemed clinically stable and without complications such as perivalvular abscess. Oral antibiotics, usually given in combination, were selected by infectious disease providers for their favorable pharmacologic properties and predicted bactericidal activity. There was a careful selection of patients who were transitioned to oral regimens. Before recommending routine use of oral antibiotics in the care of patients with IE, additional studies that better define eligible patients and that use regimens available in the countries that adopt this practice should be performed. If further studies confirm non-inferior outcomes with partial oral antibiotics for the treatment of IE, medical treatment could be delivered in a simpler, more costeffective manner, and likely with lower rates of adverse side-effects.

Practice Patterns of Infectious Diseases Physicians in Transitioning From Intravenous to Oral Therapy in Patients With Bacteremia

Background

Bacteremia in adult patients has traditionally been treated with extended courses of intravenous antibiotics. Data on the use of (or rapid transition to) oral therapy are limited.

Methods

Adult infectious disease physicians participating in the Infectious Diseases Society of America Emerging Infections Network (EIN) were surveyed regarding their use of oral antibiotics in patients with bacteremia. Respondents were asked to assume that patients were hemodynamically stable, recovered bacteria were susceptible to potential antibiotics, adequate source control had been achieved, and patients had adequate gastrointestinal absorption. Variables of specific bacteria, oral agent, and associated infection were included.

Results

A total of 655 (50%) of 1321 EIN participants responded. Under certain conditions, 88% would transition patients with Gram-negative bacteremia to complete a course of therapy with oral antibiotics; 71% would transition patients with Gram-positive bacteremia to oral agents. Only 78 (12%) respondents would not treat any bacteremic patient with oral agents. Most respondents (≥75%) were comfortable treating infections secondary to Enterobacteriaceae, Salmonella, Pseudomonas, Stenotrophomonas, Streptococcus pneumoniae, and β-hemolytic streptococci with oral agents. Fewer than 20% endorsed use of oral antibiotics for Staphylococcus aureus or in cases of endocarditis. Fluoroquinolones and trimethoprim-sulfamethoxazole were the preferred agents in Gram-negative bacteremia; linezolid and β-lactams were the preferred agents in Gram-positive bacteremia.

Conclusions

In select circumstances, the majority of respondents would transition patients to oral antibiotics, in both Gram-negative and Gram-positive bacteremia. Most agreed with the use of oral agents in Gram-negative bacteremia caused by Enterobacteriaceae, but they would not use oral agents for Gram-positive bacteremia caused by S aureus or in endocarditis.

Significant Publications on Infectious Diseases Pharmacotherapy in 2018

PURPOSE

To summarize the top 10 most influential peer-reviewed infectious diseases (ID) pharmacotherapy articles published in the year 2018.

SUMMARY

Members of the Houston Infectious Diseases Network (HIDN) nominated articles that were thought to have most notably contributed to ID pharmacotherapy in 2018, including those related to human immunodeficiency virus (HIV). A total of 26 articles were nominated: 22 articles pertaining to general ID pharmacotherapy and 4 articles involving HIV/AIDS. To select the most significant articles of 2018, a survey was created and distributed to members of the Society of Infectious Diseases Pharmacists (SIDP) asking members to vote on their top 10 general ID publications and 1 HIV publication. Of the 462 members surveyed, 213 (46%) and 108 (23%) voted for general ID pharmacotherapy- and HIV-related articles, respectively. The top article(s) for both categories are summarized.

CONCLUSION

With the increased emphasis on antimicrobial stewardship initiatives and the growing problem of multidrug-resistant (MDR) organisms, the amount of ID literature centered on stewardship, appropriate treatment durations, and newly approved antimicrobial agents continues to expand, making it challenging for clinicians to stay informed on the most relevant publications. This review summarizes significant ID-related publications in 2018 with the goal of aiding clinicians in staying up to date on the most noteworthy publications in ID pharmacotherapy.

High-dose trimethoprim-sulfamethoxazole and clindamycin for Staphylococcus aureus endocarditis

OBJECTIVE

The mortality rate for Staphylococcus aureus endocarditis remains as high as 20-30% despite improvements in medical and surgical treatment. This study evaluated the efficiency and tolerance of a combination of intravenous trimethoprim-sulfamethoxazole and clindamycin (T&C) +/- rifampicin and gentamicin, with a rapid switch to oral administration of T&C.

METHODS

This before-after intervention study compared the outcomes of 170 control patients before introduction of the T&C protocol (2001-2011) with the outcomes of 171 patients in the T&C group (2012-2016). All patients diagnosed with S. aureus infective endocarditis and referred to the study centre between 2001 and 2016 were included. Between 2001 and 2011, the patients received a standardized antibiotic treatment: oxacillin or vancomycin for 6 weeks, plus gentamicin for 5 days. Since February 2012, the antibiotic protocol has included a high dose of T&C (intravenous, switched to oral administration on day 7). Rifampicin and gentamicin are also given in cases of cardiac abscess or persistent bacteraemia.

RESULTS

The two groups were slightly different. On intention-to-treat analysis, global mortality (19% vs 30%, P=0.024), in-hospital mortality (10% vs 18%, P=0.03) and 30-day mortality (7% vs 14%, P=0.05) were lower in the T&C group. The mean duration of hospital stay was significantly shorter in the T&C group (30 vs 39 days; P=0.005).

CONCLUSIONS

The management of S. aureus infective endocarditis using a rapid shift to oral administration of T&C reduced the length of hospital stay and the mortality rate.

[Infective endocarditis and specific situations: Right heart, valve prosthesis, cardiac implantable electronic device]

Right-sided infective endocarditis (IE) represents 5-10% of IE. It may occur in patients with electronic intracardiac device, central venous catheter or congenital heart disease, but the most frequent situation is intravenous drug use. Prosthetic valve IE is the most severe form of IE. The diagnosis is more challenging than that of native valve IE, as is treatment, both antibiotic treatment and surgical indications. The infection of an electronic intracardiac device is a severe disease. Both diagnostic and therapeutic strategies are difficult.

Partial Oral versus Intravenous Antibiotic Treatment of Endocarditis

BACKGROUND

Patients with infective endocarditis on the left side of the heart are typically treated with intravenous antibiotic agents for up to 6 weeks. Whether a shift from intravenous to oral antibiotics once the patient is in stable condition would result in efficacy and safety similar to those with continued intravenous treatment is unknown.

METHODS

In a randomized, noninferiority, multicenter trial, we assigned 400 adults in stable condition who had endocarditis on the left side of the heart caused by streptococcus, Enterococcus faecalis, Staphylococcus aureus, or coagulase-negative staphylococci and who were being treated with intravenous antibiotics to continue intravenous treatment (199 patients) or to switch to oral antibiotic treatment (201 patients). In all patients, antibiotic treatment was administered intravenously for at least 10 days. If feasible, patients in the orally treated group were discharged to outpatient treatment. The primary outcome was a composite of all-cause mortality, unplanned cardiac surgery, embolic events, or relapse of bacteremia with the primary pathogen, from the time of randomization until 6 months after antibiotic treatment was completed.

RESULTS

After randomization, antibiotic treatment was completed after a median of 19 days (interquartile range, 14 to 25) in the intravenously treated group and 17 days (interquartile range, 14 to 25) in the orally treated group (P=0.48). The primary composite outcome occurred in 24 patients (12.1%) in the intravenously treated group and in 18 (9.0%) in the orally treated group (between-group difference, 3.1 percentage points; 95% confidence interval, -3.4 to 9.6; P=0.40), which met noninferiority criteria.

CONCLUSIONS

In patients with endocarditis on the left side of the heart who were in stable condition, changing to oral antibiotic treatment was noninferior to continued intravenous antibiotic treatment. (Funded by the Danish Heart Foundation and others; POET ClinicalTrials.gov number, NCT01375257 .).

Development of a Dual-Acting Antibacterial Agent (TNP-2092) for the Treatment of Persistent Bacterial Infections

The clinical management of prosthetic joint infections and other persistent bacterial infections represents a major unmet medical need. The rifamycins are one of the most potent antibiotic classes against persistent bacterial infections, but bacteria can develop resistance to rifamycins rapidly and the clinical utility of the rifamycin class is typically limited to antibiotic combinations to minimize the development of resistance. To develop a better therapy against persistent bacterial infections, a series of rifamycin based bifunctional molecules were designed, synthesized, and evaluated with the goal to identify a dual-acting drug that maintains the potent activity of rifamycins against persistent pathogens and at the same time minimize the development of rifamycin resistance. TNP-2092 was identified as a drug candidate and is currently in an early stage of clinical development for the treatment of prosthetic joint infections.

A comparison of different antibiotic regimens for the treatment of infective endocarditis

BACKGROUND

Infective endocarditis is a microbial infection of the endocardial surface of the heart. Antibiotics are the cornerstone of treatment, but their use is not standardised, due to the differences in presentation, populations affected and the wide variety of micro-organisms that can be responsible.

OBJECTIVES

To assess the existing evidence about the clinical benefits and harms of different antibiotics regimens used to treat people with infective endocarditis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE Classic and EMBASE, LILACS, CINAHL and the Conference Proceedings Citation Index on 30 April 2015. We also searched three trials registers and handsearched the reference lists of included papers. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of antibiotic regimens for treating possible infective endocarditis diagnosed according to modified Duke's criteria. We considered all-cause mortality, cure rates and adverse events as the primary outcomes. We excluded people with possible infective endocarditis and pregnant women.

DATA COLLECTION AND ANALYSIS

Three review authors independently performed study selection, 'Risk of bias' assessment and data extraction in duplicate. We constructed 'Summary of findings' tables and used GRADE methodology to assess the quality of studies. We described the included studies narratively.

MAIN RESULTS

Four small randomised controlled trials involving 728 allocated/224 analysed participants met our inclusion criteria. These trials had a high risk of bias. Drug companies sponsored two of the trials. We were unable to pool the data due to the heterogeneity in outcome definitions and the different antibiotics used.The included trials compared the following antibiotic schedules. The first trial compared quinolone (levofloxacin) plus standard treatment (anti-staphylococcal penicillin (cloxacillin or dicloxacillin), aminoglycoside (tobramycin or netilmicin) and rifampicin) versus standard treatment alone reporting uncertain effects on all-cause mortality (8/31 (26%) with levofloxacin plus standard treatment versus 9/39 (23%) with standard treatment alone; RR 1.12, 95% CI 0.49 to 2.56, very low quality evidence). The second trial compared daptomycin versus low-dose gentamicin plus an anti-staphylococcal penicillin (nafcillin, oxacillin or flucloxacillin) or vancomycin. This showed uncertain effects in terms of cure rates (9/28 (32.1%) with daptomycin versus 9/25 (36%) with low-dose gentamicin plus anti-staphylococcal penicillin or vancomycin, RR 0.89 95% CI 0.42 to 1.89; very low quality evidence). The third trial compared cloxacillin plus gentamicin with a glycopeptide (vancomycin or teicoplanin) plus gentamicin. In participants receiving gentamycin plus glycopeptide only 13/23 (56%) were cured versus 11/11 (100%) receiving cloxacillin plus gentamicin (RR 0.59, 95% CI 0.40 to 0.85; very low quality evidence). The fourth trial compared ceftriaxone plus gentamicin versus ceftriaxone alone and found no conclusive differences in terms of cure (15/34 (44%) with ceftriaxone plus gentamicin versus 21/33 (64%) with ceftriaxone alone, RR 0.69, 95% CI 0.44 to 1.10; very low quality evidence).The trials reported adverse events, need for cardiac surgical interventions, uncontrolled infection and relapse of endocarditis and found no conclusive differences between comparison groups (very low quality evidence). No trials assessed septic emboli or quality of life.

AUTHORS' CONCLUSIONS

Limited and very low quality evidence suggested that there were no conclusive differences between antibiotic regimens in terms of cure rates or other relevant clinical outcomes. However, because of the very low quality evidence, this needs confirmation. The conclusion of this Cochrane review was based on randomised controlled trials with high risk of bias. Accordingly, current evidence does not support or reject any regimen of antibiotic therapy for treatment of infective endocarditis.

Switch to oral antibiotics in the treatment of infective endocarditis is not associated with increased risk of mortality in non-severely ill patients

Although many international guidelines exist for the management of infective endocarditis (IE), recommendations are lacking on the opportunity of switching antibiotics from the intravenous (IV) to oral route during treatment. We present a cohort study of 426 cases of IE over a period of 13 years (2000-2012), including 369 cases of definite IE according to the Duke criteria. Predictors of mortality were identified using the Cox proportional hazard analysis. The median (range) age at diagnosis was 64.5 (7-98) years. One hundred six patients (25%) had healthcare-associated IE. Oral streptococci (n = 99, 23%) and Staphylococcus aureus (n = 81, 19%) were the predominant microorganisms. Ninety-two patients (22%) died during follow-up. After an initial phase of IV antibiotherapy, 214 patients (50%) were switched to oral route a median (range) of 21 (0-70) days after diagnosis of IE. Patients in the oral group had fewer comorbidities, and criteria of severity at inclusion and were less frequently infected by S. aureus. Oral antibiotics were amoxicillin alone in 109 cases or a combination therapy of clindamycin, fluoroquinolone, rifampicin and/or amoxicillin in 46 cases, according to the susceptibility of the microorganisms. In the multivariate analysis, a switch to oral route was not associated with an increased risk of mortality. During follow-up, only two relapses and four reinfections were observed in the oral group (compared to nine and eight in the IV group, respectively). In this study, switching to oral administration was not associated with an increased risk of relapse or reinfection. These promising results need to be confirmed by prospective studies.

Nanoparticle-Based Therapies for Wound Biofilm Infection: Opportunities and Challenges

Clinical data from human chronic wounds implicates biofilm formation with the onset of wound chronicity. Despite the development of novel antimicrobial agents, the cost and complexity of treating chronic wound infections associated with biofilms remain a serious challenge, which necessitates the development of new and alternative approaches for effective anti-biofilm treatment. Recent advancement in nanotechnology for developing a new class of nanoparticles that exhibit unique chemical and physical properties holds promise for the treatment of biofilm infections. Over the last decade, nanoparticle-based approaches against wound biofilm infection have been directed toward developing nanoparticles with intrinsic antimicrobial properties, utilizing nanoparticles for controlled antimicrobials delivery, and applying nanoparticles for antibacterial hyperthermia therapy. In addition, a strategy to functionalize nanoparticles towards enhanced penetration through the biofilm matrix has been receiving considerable interest recently by means of achieving an efficient targeting to the bacterial cells within biofilm matrix. This review summarizes and highlights the recent development of these nanoparticle-based approaches as potential therapeutics for controlling wound biofilm infection, along with current challenges that need to be overcome for their successful clinical translation.

Managing infective endocarditis in the elderly: new issues for an old disease

The incidence of infective endocarditis (IE) rises in industrialized countries. Older people are more affected by this severe disease, notably because of the increasing number of invasive procedures and intracardiac devices implanted in these patients. Peculiar clinical and echocardiographic features, microorganisms involved, and prognosis of IE in elderly have been underlined in several studies. Additionally, elderly population appears quite heterogeneous, from healthy people without past medical history to patients with multiple diseases or who are even bedridden. However, the management of IE in this population has been poorly explored, and international guidelines do not recommend adapting the therapeutic strategy to the patient's functional status and comorbidities. Yet, if IE should be treated according to current recommendations in the healthiest patients, concerns may rise for older patients who suffer from several chronic diseases, especially renal failure, and are on polypharmacy. Treating frailest patients with high-dose intravenous antibiotics during a prolonged hospital stay as recommended for younger patients could also expose them to functional decline and toxic effect. Likewise, the place of surgery according to the aging characteristics of each patient is unclear. The aim of this article is to review the recent data on epidemiology of IE and its peculiarities in the elderly. Then, its management and various therapeutic approaches that can be considered according to and beyond guidelines depending on patient comorbidities and frailty are discussed.

Addressing Concerns about Changing the Route of Antimicrobial Administration from Intravenous to Oral in Adult Inpatients

BACKGROUND

Many health care institutions are in the process of establishing antimicrobial stewardship programs. Changing the route of administration of antimicrobial agents from intravenous to oral (IV to PO) is a simple, well-recognized intervention that is often part of an antimicrobial stewardship program. However, the attending health care team may have concerns about making this switch.

OBJECTIVES

To provide insights into common concerns related to IV to PO conversion, with the aim of helping antimicrobial stewardship teams to address them.

DATA SOURCES

Published clinical trials and reviews were identified from a literature search of Ovid MEDLINE with the keywords (step down or switch or conversion or transition or sequential) and (antibiotics or antibacterial agents or antimicrobial or anti-infective agents).

DATA SYNTHESIS

The following issues are addressed in this review: benefits of the oral route, serum concentrations yielded by the oral formulation, source of pharmacokinetic data, clinical outcomes, provision of care in the intensive care unit, fear of therapeutic failure, and administration of antimicrobials via feeding tube.

CONCLUSIONS

When considering a change to oral therapy, it is important to have a thorough understanding of key aspects of the antimicrobial agent, the patient, and the disease being treated. The antimicrobial stewardship team has an important role in facilitating IV to PO conversion, educating prescribers, and addressing any concerns or reservations that may interfere with timely transition from IV to PO administration.

Haemophilus parainfluenzae aortic prosthetic valve endocarditis (PVE) successfully treated with oral levofloxacin

Antibiotic treatment of native valve infective endocarditis (IE) traditionally consists of 4-6 weeks of intravenous (IV) antibiotic therapy. Oral (PO) antibiotic therapy is being used more frequently, for part or all of treatment for IE but experience in treating IE with PO antibiotics is limited. Preferable agents for oral therapy of IE are antibiotics with a high degree of activity against the IE pathogen and that have high bioavailability (>90%) so that achievable serum and tissue levels are the same as with equivalent IV antibiotics. Oral antibiotic therapy of IE has several advantages over IV therapy given the long duration of treatment, i.e., 4-6 weeks for IE. Firstly, outpatient oral therapy for IE is easily administered over 4-6 weeks and decreases hospital length of stay (LOS). Secondly, oral antibiotics (administered at the same dose, frequency and duration) costs much less than their IV counterparts. Thirdly, with PO therapy for IE there are no central venous catheter (CVC) associated complications, e.g., phlebitis, bacteremia, fungemia. Compared to native valve IE, prosthetic valve endocarditis (PVE), depending on the IE pathogen, requires prolonged therapy and usually valve replacement. Haemophilus sp. IE is relatively virulent and often complicated by heart failure and/or embolic phenomena. We describe the first reported case of Haemophilus parainfluenzae aortic PVE successfully treated with oral levofloxacin without aortic valve replacement.

A mini review on pyridoacridines: Prospective lead compounds in medicinal chemistry

Natural products are increasingly being considered “critical and important” in drug discovery paradigms as a number of them such as camptothecin, penicillin, and vincristine serve as “lead molecules” for the discovery of potent compounds of therapeutic interests namely irinotecan, penicillin G, vinblastine respectively. Derived compounds of pharmacological interests displayed a wide variety of activity viz. anticancer, anti-inflammatory, antimicrobial, anti-protozoal, etc.; when modifications or derivatizations are performed on a parent moiety representing the corresponding derivatives. Pyridoacridine is such a moiety which forms the basic structure of numerous medicinally important natural products such as, but not limited to, amphimedine, ascididemin, eilatin, and sampangine. Interestingly, synthetic analogues of natural pyridoacridine exhibit diverse pharmacological activities and in view of these, natural pyridoacridines can be considered as “lead compounds”. This review additionally provides a brief but critical account of inherent structure activity relationships among various subclasses of pyridoacridines. Furthermore, the current aspects and future prospects of natural pyridoacridines are detailed for further reference and consideration.