Safety and efficacy of long-term outpatient ertapenem therapy

Outpatient Parenteral Antimicrobial Therapy with Carbapenems: a systematic review

OBJECTIVE

To review the literature on parenteral carbapenems in OPAT and present comprehensive evidence on their safety, efficacy, and stability.

METHODS

A systematic review following PRISMA guidelines was conducted through 17 January, 2024, using PubMed, Embase, Web of Science, Scopus, and the Cochrane Library to find relevant articles.

RESULTS

Ertapenem (1g QD) in OPAT showed high clinical (81-97%) and microbiological (67-90.9%) success rates. Ertapenem (1g QD) was also comparable to piperacillin/tazobactam (3.375g every 6h) for complicated skin infections and superior to cefazolin (2g every 8h) and oxacillin (2g every 4-6h) for various infections. Ertapenem monotherapy, once daily, achieved an 81% clinical cure rate for urinary tract infections. Additionally, subcutaneous ertapenem in OPAT showed outcomes comparable to parenteral routes. Meropenem continuous infusion (CI) may also be considered safe and effective in selected patient populations; however, its use in OPAT as a CI is limited due to stability concerns.

CONCLUSION

Parenteral carbapenems are effective, and well-tolerated OPAT treatment options; nonetheless, further studies are warranted to optimize the stability and/or dosing regimens of meropenem and enable its wider use.

Current practices and challenges of outpatient parenteral antimicrobial therapy: a narrative review

Extended hospitalization for infection management increases inpatient care costs and the risk of healthcare-associated adverse events, including infections. The growing global demand for healthcare, the diminishing availability of hospital beds and an increasing patient preference for care within their own home have been the primary drivers of the expansion of hospital-in-the-home programmes. Such programmes include the use of IV antimicrobials in outpatient settings, known as outpatient parenteral antimicrobial therapy (OPAT). However, OPAT practices vary globally. This review article aims to describe the current OPAT practices and challenges worldwide. OPAT practice begins with patient evaluation and selection using eligibility criteria, which requires collaboration between the interdisciplinary OPAT team, patients and caregivers. Depending on care requirements, eligible patients may be enrolled to various models of care, receiving medication by healthcare professionals at outpatient infusion centres, hospital clinics, home visits or through self-administration. OPAT can be used for the management of many infections where an effective oral treatment option is lacking. Various classes of parenteral antimicrobials, including β-lactams, aminoglycosides, glycopeptides, fluoroquinolones and antifungals such as echinocandins, are used globally in OPAT practice. Despite its benefits, OPAT has numerous challenges, including complications from medication administration devices, antimicrobial side effects, monitoring requirements, antimicrobial instability, patient non-adherence, patient OPAT rejection, and challenges related to OPAT team structure and administration, all of which impact its outcome. A negative outcome could include unplanned hospital readmission. Future research should focus on mitigating these challenges to enable optimization of the OPAT service and thereby maximize the documented benefits for the healthcare system, patients and healthcare providers.

OUP accepted manuscript

Objectives

Ertapenem has proven to be an effective antimicrobial; however, increasing enzyme-mediated resistance has been noted. Combination with zidebactam, a β-lactam enhancer, is restorative. Human-simulated regimens (HSRs) of ertapenem and zidebactam alone and in combination (WCK 6777; 2 g/2 g q24h) were assessed for efficacy against carbapenemase-producing Klebsiella pneumoniae (CP-KP) in the pneumonia model.

Methods

Infected ICR mice were rendered neutropenic and exposed to various doses of ertapenem and zidebactam alone and in combination to develop the HSRs that were subsequently confirmed in additional pharmacokinetic studies. Twenty-one CP-KP (KPC or OXA-48-like producers) with WCK 6777 MICs of 1–8 mg/L were utilized. Mice were treated for 24 h with saline or HSRs of ertapenem, zidebactam and WCK 6777. Efficacy was defined as change in mean lung bacterial density relative to 0 h.

Results

Confirmatory pharmacokinetic analysis showed agreement between predicted human exposures (%fT_>MIC) and those achieved in vivo for all three HSRs. The 0 h bacterial density across all isolates was 6.69 ± 0.31 log₁₀ cfu/lungs. At 24 h, densities increased by 2.57 ± 0.50, 2.2 ± 0.60 and 2.05 ± 0.71 log₁₀ cfu/lungs in the 24 h control, ertapenem HSR and zidebactam HSR groups, respectively. Overall, 18/21 of the isolates exposed to the WCK 6777 HSR displayed a killing profile that exceeded the translational benchmark for efficacy of a 1 log₁₀ cfu reduction. Among the remaining three isolates, two displayed ∼0.5 log₁₀ kill and stasis was observed in the third.

Conclusions

Human-simulated exposures of WCK 6777 demonstrated potent in vivo activity against CP-KP, including those with WCK 6777 MICs up to 8 mg/L.

Efficacy and cost-effectivity analysis of outpatient parenteral antimicrobial therapy unit in infectious disease clinical practices: Turkey perspective

BACKGROUND

Outpatient parenteral antimicrobial treatment (OPAT) has become a common treatment modality in developed countries. OPAT units are not widespread in Turkey, and their cost-effectivity analysis has not been studied, yet.

AIMS

To analyze the clinical efficacy and cost-effectiveness of the OPAT unit, based on a 1000-bed teaching hospital.

METHODS

The records of patients, who were treated between October 2013 and December 2017, in an OPAT unit of a tertiary hospital in Ankara, were obtained retrospectively. The cost that would arise if the patients were hospitalized for the same treatment period with the same diagnosis was calculated and compared with the actual treatment cost of the patients in the OPAT unit.

RESULTS

A total of 594 patients who received antimicrobial treatment at the OPAT unit were enrolled. The mean age of the patients was 55.39 ± 16.37 years and 313 (52.7%) were males. Based on the end-of-treatment goals, 98.5% of the patients reached the treatment goal. An indirect cost analysis revealed that the OPAT unit was 487.625 94 TL/129.008 78 $ less costly than inpatient parenteral antibiotic treatment. In other words, OPAT cost was 75% of the equivalent inpatient costs. It was also determined that a total of 7078 bed days and 11.9 bed days per person were saved.

CONCLUSIONS

OPAT units should be expanded increasingly in Turkey. The evaluation together with the health care system conditions in Turkey revealed that the OPAT program is safe, effective, and cost-efficient.

Investigating auranofin for the treatment of infected diabetic pressure ulcers in mice and dermal toxicity in pigs

Bacterial infection of pressure ulcers (PUs) are a notable source of hospitalization for individuals with diabetes. This study evaluated the safety profile and efficacy of auranofin to treat diabetic PUs infected with methicillin-resistant Staphylococcus aureus (MRSA). PUs were infected with MRSA in diabetic TALLYHO/JngJ mice and then treated with topical auranofin (2%), topical mupirocin (2%), or oral clindamycin (30 mg/kg) for four days. PUs were harvested post-treatment to enumerate bacterial burden and determine expression of cytokines/growth factors. Landrace cross pigs were exposed topically to auranofin (1%, 2%, and 3%) for 4-14 days and evaluated for signs of localized or systemic toxicity. Auranofin eradicated MRSA in PUs within four days (7.92-log10 reduction) in contrast to mupirocin (2.15-log10 reduction) and clindamycin (0.73-log10 reduction). Additionally, auranofin treatment resulted in decreased expression of pro-inflammatory cytokines and increased expression of biomarkers associated with re-epithelization of wounded tissue, confirmed with histopathologic analysis. No significant histopathologic lesions were present on porcine skin sites exposed to topical auranofin. Additionally, minimal accumulation of plasma gold and no systemic toxicity was observed in pigs exposed to topical auranofin. Auranofin appears to be a potent and safe topical agent to further investigate for treatment of mild-to-moderate MRSA-infected diabetic PUs.

Experiences in outpatient parenteral antimicrobial therapy (OPAT): Barriers and challenges from the front lines

Background:

Outpatient parenteral antimicrobial therapy (OPAT) is now the standard of care for managing patients who no longer need inpatient care but require prolonged intravenous antimicrobial therapy. OPAT increases patient satisfaction, reduces the lengths of hospital stay, lowers emergency department readmission rates, and decreases total healthcare spending.

Objective:

To investigate Virginia Commonwealth University Health System’s experience with OPAT and to highlight the obstacles patients and clinicians face when navigating and utilizing this program.

Design:

We conducted this descriptive study at a large, academic, tertiary-care hospital in Central Virginia.

Methods:

We performed manual reviews of electronic medical records of 602 patient, and we evaluated the records of those receiving OPAT between 2017 and 2020. Reviews included antimicrobial agents, diagnoses requiring OPAT, adverse effects related to antimicrobials, adverse effects related to peripherally inserted central catheters (PICC), readmission rate, discharge destination, and death. We evaluated our program with descriptive statistics.

Results:

Among 602 patients who received OPAT, most were diagnosed with bacteremia or musculoskeletal infections. Patients were either discharged home or to another healthcare facility, with the former comprising most of the rehospitalizations. Ertapenem and vancomycin were associated with the most adverse drug events among our cohort. Elevated transaminase levels were noted in 23% of patients. The rate of PICC-line adverse events in this study population was 0.05%.

Conclusions:

Our findings highlight the barriers and challenges that patients and providers face when receiving OPAT, and they can inform efforts to improve patient clinical outcomes.

Calculated initial parenteral treatment of bacterial infections: Skin and soft tissue infections

This is the ninth chapter of the guideline "Calculated Parenteral Initial Therapy of Adult Bacterial Disorders - 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. The chapter contains the first German S2k guidelines for bacterial skin and soft tissue infections. They encompass recommendations on diagnosis and treatment of the defined entities erysipelas (caused by beta-hämolytic streptococci), limited superficial cellulitis (S. aureus), severe cellulitis, abscess, complicated skin and soft tissue infections, infections of feet in diabetic patients ("diabetic foot"), necrotizing soft tissue infection and bite injuries.

Shortening duration of ertapenem in outpatient parenteral antimicrobial therapy for complicated urinary tract infections: A retrospective study

Background

The incidence of multi-drug resistant ESBL-associated urinary tract infections (UTIs) is increasing globally. Patients with abnormal renal tract anatomy and other co-morbidities are at increased risk of complicated UTI and ESBL-associated infections. The duration and safety of OPAT for this cohort of patients is unknown.

Objectives

This study aims to provide an evidence base to support decision-making regarding duration of antibiotic treatment for complicated UTIs.

Methods

We retrospectively reviewed all patients receiving ertapenem with or without adjunctive fosfomycin for complicated UTIs in the OPAT service of our tertiary infectious diseases hospital. All data had been collected prospectively as part of routine clinical care. Our primary outcomes were microbiological and clinical cure of UTI.

Results

We identified 33 treatment episodes of ertapenem use for UTIs. 76% episodes related to pyelonephritis or urosepsis diagnoses. Renal tract abnormalities or prior urological surgery were present in 45% of patients. The median duration of appropriate parenteral antibiotic therapy in our study was 6 days. Clinical cure was achieved with short-course parenteral treatment alone in 81% of patients and this increased to 96% when adjunctive fosfomycin was used. There was a single treatment failure resulting in hospital admission.

Conclusions

Short duration ertapenem via OPAT with or without adjunctive fosfomycin is safe and effective for the treatment of complicated UTIs. Further studies are required to inform optimal treatment strategies and publication of guidelines in this field.

Updated good practice recommendations for outpatient parenteral antimicrobial therapy (OPAT) in adults and children in the UK

UK good practice recommendations for outpatient parenteral antimicrobial therapy (OPAT) were published in 2012 and 2015 for adult and paediatric patients, respectively. Here we update the initial good practice recommendations in a combined document based on a further review of the OPAT literature and an extensive consultation process. As with the previous good practice recommendations, these updated recommendations are intended to provide pragmatic guidance for new and established OPAT services across a range of settings and to act as a set of quality indicators for service evaluation and quality improvement.

Outpatient ertapenem therapy in an ESBL-high-prevalence area: an efficacy, safety, and cost study

Introduction

Outpatient parenteral antimicrobial therapy is a safe, effective, and convenient way of administering antimicrobials for a wide variety of infections. So far there are no reports on the efficacy of outpatient antimicrobial therapy in Mexico. Our objective was to determine the outcomes, safety, and cost of outpatient ertapenem therapy (OET) in our hospital.

Patients and methods

A case series of 99 patients that received intravenous OET was conducted. The primary outcomes were clinical cure, relapse, and recurrence of infection.

Results

Of the 99 patients who received OET the most common diagnosis was urinary tract infection in 56%. Extended-spectrum-β-lactamase-producing Enterobacteriaceae caused 67% of infections in our population. Ninety-seven percent of the patients were cured at the completion of OET. One patient presented relapse 12 days after the end of OET; two patients presented recurrence, one with skin and soft tissue infection and one with pyelonephritis at days 35 and 34, respectively, after the end of OET. Three patients were readmitted after OET, one with an episode of phlebitis, one with recurrence, and one with relapse. A case of non-Clostridium difficile-associated diarrhea was observed. The intravascular line complications observed during OET were phlebitis in two patients.

Conclusion

In our hospital, the OET was found to be effective, safe, and cost-saving when compared to inpatient care.

Efficacy and Cost Comparison of Ertapenem as Outpatient Parenteral Antimicrobial Therapy in Acute Pyelonephritis due to Extended-spectrum Beta-lactamase-producing Enterobacteriaceae

Outpatient parenteral antimicrobial therapy (OPAT) programs are becoming an increasingly popular trend in clinical practice as they offer several benefits to both patients and health-care setups. While OPAT is an established clinical practice in the Western world, the concept itself is alien to patients in India as they prefer the security of hospitals to receive antibiotics over OPAT. We evaluated the clinical response and cost comparison of ertapenem under OPAT versus inpatient settings in patients with extended-spectrum beta-lactamase (ESBL)-positive acute pyelonephritis (APN) given the increasing importance of optimizing both hospital beds and overall cost of patient care in India. APN was chosen as the indication to be studied as it is one of the common complicated urinary tract infections treated in our OPAT unit requiring 10–14 days of parenteral therapy with an agent active against various Gram-negative bacilli and multidrug-resistant organisms. One hundred patients were retrospectively studied based on whether antibiotics were administered during hospital stay alone (hospital only), during both hospital stay, and also as OPAT post discharge (hospital/OPAT) or as OPAT alone (OPAT only). Response to ertapenem and cost of treatment in inpatient versus OPAT settings were compared using Pearson's Chi-square or Fisher's exact test for categorical variables. ANOVA (or Kruskal–Wallis) was used for continuous variables. Baseline urine cultures were ESBL positive with 98% prevalence of Gram-negative bacilli (GNB). Colony counts were ≥100,000 in 74% patients. Only ertapenem, imipenem, and meropenem showed 100% sensitivity to ESBL-positive GNB in baseline urine culture and sensitivity reports. Ertapenem showed 100% sensitivity and complete clinical resolution for 96% patients with APN due to ESBL Enterobacteriaceae. It was administered as OPAT in 90% patients and significantly reduced overall treatment costs.

A Case of Linezolid Induced Toxicity

Adverse effects of linezolid are typically limited to diarrhea, nausea, and headache when shorter durations are used; however, as extended durations of linezolid therapy are increasingly more common, additional monitoring parameters should be considered in these patients. We describe a unique case of hypoglycemia, lactic acidosis, and pancreatitis related to an extended duration of linezolid therapy. A 52-year-old woman presented with altered mental status, abdominal pain, and hypotension following six weeks of linezolid and ertapenem therapy. Laboratory data revealed an initial blood glucose of 40 mg/dL and metabolic acidosis secondary to lactic acidosis. Finally, her abdominal pain on admission was likely related to an enlarged pancreas noted on computed tomography of her abdomen. Due to suspected linezolid toxicity, the patient received two intermittent hemodialysis sessions to remove linezolid and correct the metabolic acidosis. Given limited data on long-term monitoring of patients receiving extended durations of linezolid therapy, we suggest periodic monitoring of lactate, arterial blood gas, and blood glucose. If patients present with this triad of symptoms secondary to linezolid therapy, adverse effects should be treated with dextrose and intravenous thiamine while reserving hemodialysis for those with metabolic acidosis refractory to thiamine.

Ertapenem in outpatient parenteral antimicrobial therapy for complicated urinary tract infections

BACKGROUND

Ertapenem is a broad-spectrum antibiotic that is increasingly being utilized. Its dosing convenience renders it suitable for outpatient therapy, and its pharmacokinetic characteristics favour its use against complicated urinary tract infections (cUTIs). Despite this, sufficient clinical data are lacking for its use against cUTIs in the outpatient setting. We assessed the microbiological and clinical cure rates associated with ertapenem treatment for cUTIs in two outpatient parenteral antimicrobial therapy (OPAT) departments.

METHODS

We undertook a prospective observational study of adult patients who received ertapenem for cUTIs between August 2010 and August 2014. Data on patient characteristics, clinical progress and microbiological results were collected and analysed.

RESULTS

Sixty-one patients were enrolled. The median age was 59 years (range 24, 83) and 61% were male. The most common diagnoses were pyelonephritis (39%) and prostatitis (15%). The most common causative organism was Escherichia coli (67%). Extended-spectrum β-lactamase (ESBL)-producing organisms were detected in 72% of infections. Microbiological cure was achieved in 67% overall, and was less likely in those with Klebsiella pneumoniae infection (OR = 0.21 [95%CI: 0.05 to 0.85] p = 0.029). Clinical cure was observed in 92% of patients.

CONCLUSION

In this study of treating cUTIs with ertapenem, we have demonstrated good clinical outcomes. A lower than expected microbiological cure rate was observed in those with Klebsiella pneumoniae infection.

Differential characteristics of healthcare-associated compared to community-acquired febrile urinary tract infections in males

The objective of this study was to analyse the characteristics of healthcare-associated febrile urinary tract infection (HCA-FUTI) compared to community-acquired FUTI (CA-FUTI) in men. An ambispective cross-sectional study in which we recorded clinical and microbiology data and outcomes from males with FUTI attended in the Emergency Department was carried out. A total of 479 males with FUTI, 162 (33.8%) HCA-FUTI and 317 (66.2%) CA-FUTI, were included. HCA-FUTI patients were older (p < 0.001), had higher Charlson scores (p < 0.001) and received previous antimicrobial treatment more frequently (p < 0.001) compared to CA-FUTI patients. HCA-FUTI was less likely caused by Escherichia coli (p < 0.001) and more frequently by Klebsiella spp. (p = 0.02), Enterobacter spp. (p < 0.001) and Pseudomonas aeruginosa (p < 0.001). Resistance to ceftriaxone (p = 0.006), gentamicin (p < 0.001), quinolones (p < 0.001), co-trimoxazole (p = 0.001) and fosfomycin (p = 0.009) was higher among E. coli strains isolated from males with HCA-FUTI and so was the prevalence of extended-spectrum beta-lactamase and AmpC E. coli and Klebsiella spp.-producing strains (p = 0.012). Inadequate antimicrobial treatment and all-cause in-hospital mortality was associated with HCA-FUTI (p < 0.001 and p = 0.004, respectively). Independent factors for mortality were severe sepsis or septic shock [odds ratio (OR) 29; 95% confidence interval (CI): 3.9-214] and cirrhosis (OR 23.7; 95% CI: 1.6-350.6). Male patients with HCA-FUTI have different clinical characteristics, outcomes and microbiological features compared to CA-FUTI patients. Previous contact with the healthcare system has to be taken into consideration when deciding the optimal antimicrobial treatment in males with FUTI.

Comparative outcomes of β-lactam antibiotics in outpatient parenteral antibiotic therapy: treatment success, readmissions and antibiotic switches

OBJECTIVES

β-Lactam antibiotics are commonly used in outpatient parenteral antimicrobial therapy (OPAT), but data regarding outcomes of long-term therapy are limited. The purpose of this study was to compare treatment success, readmission and antibiotic switch rates in patients treated with β-lactam antibiotics as OPAT.

METHODS

We carried out a retrospective review of all patients, discharged from Tufts Medical Center with cefazolin, ceftriaxone, ertapenem or oxacillin, between January 2009 and June 2013. A competing risks analysis was used to compare the cumulative incidence of first occurrence of treatment success, antibiotic switch and 30 day readmission for each drug.

RESULTS

Four hundred patients were identified (cefazolin n = 38, ceftriaxone n = 104, ertapenem n = 128 and oxacillin n = 130). Baseline demographics were similar. Treatment success rates were higher for ceftriaxone and ertapenem (cefazolin 61%, ceftriaxone 81%, ertapenem 73% and oxacillin 58%; P < 0.001). Thirty-day all-cause readmissions were similar (cefazolin 21%, ceftriaxone 14%, ertapenem 20% and oxacillin 15%; P = 0.46). In 400 OPAT courses, 37 out of 50 antibiotic switches were accomplished without readmission. Adverse drug events (ADEs) were the most common reason for outpatient antibiotic switches (31/37, 84%). The ADE rate was higher for the oxacillin group (cefazolin 2.0 versus ceftriaxone 1.5 versus ertapenem 2.9 versus oxacillin 8.4 per 1000 OPAT days; P < 0.001).

CONCLUSIONS

OPAT with β-lactam antibiotics is effective, but antibiotic switches for adverse events were more frequent with oxacillin use. Clinicians should be cognizant of the risk of readmissions and ADEs in OPAT patients, as the value of OPAT lies in reducing patient morbidity and readmissions by managing ADEs and preventing clinical failures.