Ertapenem: a review of its use in the management of bacterial infections

Efficacy and safety of ertapenem dosing in patients with ESBL producing Enterobacterales infections utilizing renal replacement therapies

PURPOSE

The clinical efficacy and safety of ertapenem use in patients undergoing renal replacement therapies (RRT) are not well-documented. Therefore, we aimed to investigate the safety and efficacy of ertapenem in patients with sepsis secondary to Enterobacterales who are undergoing RRT.

METHODS

A retrospective cohort study was conducted on patients who met the inclusion criteria at our hospital between May 2015 and December 2021. The primary endpoint was 30-day mortality. Secondary endpoints included clinical cure, microbiologic cure, recurrence rate, and incidence of seizures.

RESULTS

During the study period, 158 patients met the inclusion criteria. Of these, 86 were male (54.4%), the mean age was 66.4 ± 13.8 years, and the mean weight was 77 ± 22.4 kg. The most common diagnosis was bacteremia in 48 (30.4%) subjects, followed by urinary tract infection in 39 (24.7%) subjects, and pneumonia in 35 (22.2%) patients. The most isolated pathogens were Escherichia coli, followed by Klebsiella species. The median ertapenem dose was 0.5 g intravenously (IV) daily in those who received intermittent hemodialysis (IHD) and 1 g IV daily for those who received continuous veno-venous hemofiltration (CVVH). The 30-day mortality rate was 24%, the clinical cure rate was 89.2%, the microbiologic cure rate was 82%, the 30-day recurrence rate was 41.1%, and the incidence of seizures was 2.5%. Multivariate logistic regression analysis indicated that age (OR 1.04 [95% CI: 1.003-1.075]), being critically ill at therapy initiation (OR 2.9 [95% CI: 1.1-7.5]), and Enterobacterales other than Klebsiella species and Escherichia coli (OR 3.8 [95% CI: 1.1-12.5]) were significant independent risk factors associated with mortality in this population. Ertapenem dose was not associated with mortality.

CONCLUSION

Our findings suggest that the commonly used doses of ertapenem in patients undergoing IHD and CVVH are clinically effective but may pose a higher risk of seizures. A comprehensive pharmacokinetic study is needed to determine the most effective and safe dose for this population.

From Gut to Heart: A Case Report of Infectious Endocarditis Stemming From Cholecystitis-Induced Enterococcus faecium Bacteremia

Systemic infections are not always going to present as we expect. The study of bacteremia and febrile syndrome represents one of the most important diagnostic challenges nowadays. This case demonstrates the importance of a multidisciplinary approach and finding a common point that explains all the patient's symptoms, no matter how disconnected they may seem. Here, we present the case of a patient where multiple treatments were performed to manage recurrent infective endocarditis due to Enterococcus faecium but the cause of this persistence was never found despite surgical management. With only a few cases reported in literature involving this pathogen, it is of great importance to emphasize how searching for a natural reservoir, such as the gallbladder, for this pathogen helped solve the diagnostic mystery that this patient represented. Here, we present how the culture of biological materials, such as the aortic valve replacement, as well as blood cultures, made it possible to identify the etiological agent associated with the pathology and, in turn, find the cause of recurrent bacteremia.

Colloidal Chiral Carbon Dots: An Emerging System for Chiroptical Applications

Chiral CDots (c-CDots) not only inherit those merits from CDots but also exhibit chiral effects in optical, electric, and bio-properties. Therefore, c-CDots have received significant interest from a wide range of research communities including chemistry, physics, biology, and device engineers. They have already made decent progress in terms of synthesis, together with the exploration of their optical properties and applications. In this review, the chiroptical properties and chirality origin in extinction circular dichroism (ECD) and circularly polarized luminescence (CPL) of c-CDots is briefly discussed. Then, the synthetic strategies of c-CDots is summarized, including one-pot synthesis, post-functionalization of CDots with chiral ligands, and assembly of CDots into chiral architectures with soft chiral templates. Afterward, the chiral effects on the applications of c-CDots are elaborated. Research domains such as drug delivery, bio- or chemical sensing, regulation of enzyme-like catalysis, and others are covered. Finally, the perspective on the challenges associated with the synthetic strategies, understanding the origin of chirality, and potential applications is provided. This review not only discusses the latest developments of c-CDots but also helps toward a better understanding of the structure-property relationship along with their respective applications.

Prophylactic Antibiotic Duration and Infectious Complications in Pancreatoduodenectomy Patients With Biliary Stents: Opportunity for De-escalation

OBJECTIVE

The aim of this study was to compare infectious complications in pancreatoduodenectomy (PD) patients with biliary stents treated with short, medium, or long durations of prophylactic antibiotics.

BACKGROUND

Pre-existing biliary stents have historically been associated with higher infection risk after PD. Patients are administered prophylactic antibiotics, but the optimal duration remains unknown.

METHODS

This single-institution retrospective cohort study included consecutive PD patients from October 2016 to April 2022. Antibiotics were continued past the operative dose per surgeon discretion. Infection rates were compared by short (≤24 h), medium (>24 but ≤96 h), and long (>96 h) duration antibiotics. Multivariable regression analysis was performed to evaluate associations with a primary composite outcome of wound infection, organ-space infection, sepsis, or cholangitis.

RESULTS

Among 542 PD patients, 310 patients (57%) had biliary stents. The composite outcome occurred in 28% (34/122) short, 25% (27/108) medium, and 29% (23/80) long-duration ( P =0.824) antibiotic patients. There were no differences in other infection rates or mortality. On multivariable analysis, antibiotic duration was not associated with infection rate. Only postoperative pancreatic fistula (odds ratio 33.1, P <0.001) and male sex (odds ratio 1.9, P =0.028) were associated with the composite outcome.

CONCLUSIONS

Among 310 PD patients with biliary stents, long-duration prophylactic antibiotics were associated with similar composite infection rates to short and medium durations but were used almost twice as often in high-risk patients. These findings may represent an opportunity to de-escalate antibiotic coverage and promote risk-stratified antibiotic stewardship in stented patients by aligning antibiotic duration with risk-stratified pancreatectomy clinical pathways.

Efficacy and Durability of Intravenous Ertapenem Therapy for Recalcitrant Hidradenitis Suppurativa

Importance

Hidradenitis suppurativa (HS) is a debilitating follicular skin disorder in which bacterial colonization is typical. Oral antibiotic efficacy can be unreliable; however, selective intravenous antibiotics, specifically ertapenem, may provide favorable clinical outcomes.

Objective

To explore optimal course duration, efficacy, and patient satisfaction associated with intravenous ertapenem for HS.

Design, Setting, and Participants

This retrospective review of the medical records of 98 patients with HS between 2018 and 2022 measured and evaluated patient outcomes before and after treatment with intravenous ertapenem. Participants were followed up in a telephone survey assessing patient perspectives and satisfaction. All of those included in this study received medical care from the Albert Einstein College of Medicine's Montefiore HS Center.

Exposures

Patients were treated with 1 g of ertapenem that was self-administered at home through a peripheral intravenous central catheter using an elastomeric pump for 12 to 16 weeks. Antiandrogens and immunomodulatory biologic therapies initiated prior to ertapenem were maintained throughout the treatment course.

Main Outcomes and Measures

The primary outcomes, encompassing clinical severity (evaluated through the HS Physician Global Assessment score [a 6-point scale ranging from clear to very severe] and a numerical rating scale for pain [an 11-point scale in which a score of 0 indicates no pain and a score of 10 indicates the worst possible pain]) and markers of inflammation (such as leukocytes, erythrocyte sedimentation rate, C-reactive protein, and interleukin-6), were measured at baseline, the midcourse of intravenous ertapenem treatment, at the end of the course, and posttherapy. Bacterial abundance was also examined at these 4 points, and patient satisfaction was assessed during follow-up.

Results

A total of 98 patients (mean [SD] age, 35.8 [13.0] years; 61 [62.2%] female) with HS were treated with intravenous ertapenem. The self-reported racial distribution included 3 individuals identifying as Asian (3.1%), 59 as Black/African American (60.2%), 13 as White (13.3%), and 23 as either other or unknown (23.5%). Additionally, 24 participants (24.5%) reported Spanish/Hispanic/Latino ethnicity. The mean (SD) treatment duration spanned 13.1 (4.0) weeks, with posttherapy follow-up occurring after 7.8 (3.6) weeks. From baseline to posttherapy follow-up, significant reductions were found in the mean (SD) HS Physician Global Assessment scores (3.9 [1.0] vs 2.7 [1.2]; P < .001) and the numerical rating scale for pain (4.2 [3.3] vs 1.8 [2.7]; P < .001), C-reactive protein (5.4 [11.4] vs 2.4 [2.0] mg/dL; P < .001), interleukin-6 (25.2 [21.1] vs 13.7 [13.9]; P < .001), and leukocytes (11.34 [3.9] vs 10.0 [3.4]; P < .001). At follow-up, 76 patients (78.0%) participated in the telephone survey, where 63 (80.3%) reported medium to high satisfaction; further, 69 (90.8%) would recommend ertapenem to other patients.

Conclusions and Relevance

In this retrospective review of medical records and telephone survey, treating HS with intravenous ertapenem, administered for a mean of 13 weeks, was associated with improvement in clinical and inflammatory markers, as well as heightened patient satisfaction. Nonetheless, this approach should be monitored for the emergence of antimicrobial resistance given a longer than standard treatment course.

Ertapenem-Induced Neurotoxicity: A Literature Review of Clinical Characteristics and Treatment Outcomes

Background

Neurotoxicity is a rare adverse event for ertapenem. Given the limited evidence, large patient data are needed to aid in the identification and management of this fatal complication. Aim of the review, we summarize the characteristics, risk factors, and treatment of ertapenem-induced neurotoxicity.

Methods

Pubmed, Web of Science, Embase, Cochrane library, Wanfang, CNKI, China VIP database were searched up from 31 October 2001 to 31 December 2022. All articles concerning neurotoxicity induced by ertapenem were included. The retrieved articles were screened by two experienced clinicians by reading the titles, abstracts, and full texts.

Results

A total of 66 patients were included, with a median age of 71.5 years (range 40-92), of whom 45 (68.2%) were male. Twelve patients (18.2%) received irrational doses (exceeding the recommended dose), and 30 patients (45.5%) had chronic renal insufficiency. The median time to symptom onset was 5 (range 1-14). Epileptiform seizures (42.4%), visual hallucinations (36.4%), altered mental status (25.8%), and confusion (22.7%) were the most common symptoms of ertapenem-induced neurotoxicity. Of the 29 patients with reported albumin levels, 25 had serum albumin <3.5 g/dl. Ertapenem was discontinued in 95.5% of patients, and 90.9% recovered completely. Median time to symptom recovery was 7 days (range 1-42) after intervention including antiepileptic administration, or hemodialysis.

Conclusion

Neurotoxicity is a rare adverse event for ertapenem, especially in patients with advanced age, renal insufficiency, pre-existing neurological disease, and hypoalbuminemia. This adverse reaction usually resolves with medication interruption, or antiepileptic administration and hemodialysis.

Practical Guidelines for Managing Patients With Hidradenitis Suppurativa: An Update

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease that is characterized by the formation of comedones, papules, nodules, abscesses and sinus tracts in the axillary, inframammary, groin, and gluteal areas. Up to 3.8% of the Canadian population has HS, though due to a lack of awareness of HS, many patients are initially misdiagnosed and do not receive adequate treatment early on in the disease course. Once a diagnosis of HS is made, developing an effective management plan can be a dilemma for many providers. There is significant variability in response to any given therapy within the HS patient population and many HS patients have other medical comorbidities which must be taken into consideration. The aim of this review is to provide a practical approach for all healthcare providers to diagnose and manage HS and its associated comorbidities. A sample electronic medical record template for HS management was developed by the Canadian Hidradenitis Suppurativa Foundation Executive Board and is intended for use in clinical settings. This will help to increase collaboration between primary healthcare providers, dermatologists, and other medical specialists and ultimately improve the quality of care that HS patients receive.

A Meta-Analysis on Clinical Outcomes of Ceftolozane versus Piperacillin in Combination with Tazobactam in Patients with Complicated Urinary Tract Infections

Objective

To evaluate efficacy and adverse events of ceftolozane/tazobactam in complicated UTI including acute pyelonephritis.

Method

Databases that include PubMed, Embase, Scopus, and TRIP were searched. All randomized controlled trials and cohort studies were considered for the study. Statistical analysis was done using a fixed effects model, and results were expressed in proportion for dichotomous data and risk ratio for continuous data with 95% confidence intervals (CI).

Results

A clinical cure of ceftolozane/tazobactam was found to be 92% with 95% CI of 90-94 while that of piperacillin/tazobactam was only 78% (95% CI, 74-82) in patients with complicated UTI. Microbiological eradication was still higher in the ceftolozane/tazobactam group (83%, 95% CI 81-88) when compared with piperacillin/tazobactam (63% 95% CI, 58.77-65.2). Ceftolozane/tazobactam was more effective in the treatment of complicated urinary tract infections other than acute pyelonephritis as compared to piperacillin/tazobactam (RR = 1.21, 95% CI, 1.07-1.23). Serious adverse events were found comparable in both groups (RR = 1.15, 95% CI, 0.64-2.09).

Conclusion

The analysis showed that ceftolozane/tazobactam has better clinical outcomes including cure rates and low resistance for the treatment of complicated urinary tract infection.

Safety of Intravenous Push Ertapenem Compared to Intravenous Piggyback at a Tertiary Academic Medical Center

Background: Recent shortages of intravenous (IV) fluids have resulted in healthcare systems converting administration of many medications from IV piggyback (IVPB) to IV push (IVP). Administering medications via IVP presents numerous advantages; however, IV site reactions such as phlebitis and infiltration may occur. Objective: The objective of this analysis is to evaluate the infusion site safety of ertapenem given as peripheral IVP compared to IVPB in adult patients. Methods: This was an institutional review board-approved, single-center, retrospective study. Patients, ages 18 or older, receiving IV ertapenem were identified. The major endpoints analyzed were IV site reactions including phlebitis and infiltration. The Naranjo Nomogram was utilized to assess the causality of the reactions to determine the likelihood of whether the event was caused by the medication itself or other factors. Results: To date, 283 administrations (92 patients) in the IVP group and 319 administrations (82 patients) in the IVPB group were analyzed. There were 13 IV site reactions compared to 8 in the IVP vs IVPB group, respectively (P-value = 0.16). Ten of the events in the IVP group were deemed "possible" and 2 deemed "doubtful," while the remaining event was considered "probable" per the Naranjo Nomogram. Of the events in the IVPB group, all 8 were found to be "possible." Conclusion: The administration of IVP ertapenem showed comparable rates of infusion site reactions compared to IVPB. Implementation of IVP ertapenem appears to be associated with infusion site safety similar to IVPB and should be considered safe to administer.

Ertapenem Neurotoxicity in Hemodialysis Patients-Safe and Effective Dosing Is Still Needed: A Retrospective Study and Literature Review

BACKGROUND

The approved dosing of ertapenem in patients with chronic kidney disease stage 5 utilizing dialysis (CKD-5D) is 0.5 g intravenous daily. Several reports associated this dosing strategy with neurotoxicity.

OBJECTIVE

The purpose of this study is to identify the incidence of neurotoxicity in this population and the risk factors associated with this toxicity. The secondary objective was to review the literature and discuss a safer/cost-effective dosing strategy based on available data.

METHODS

A retrospective study was conducted screening all patients who received ertapenem and hemodialysis at our quaternary hospital between May 2015 and March 2019. Patients' demographics, comorbidities, concomitant drugs (known to induce neurotoxicity), and seizure history were collected.

RESULTS

A total of 99 eligible patients were identified; 10 of them (10%) developed neurotoxicity. The patients who developed neurotoxicity were all male; mean age was 74 ± 9 years as compared with 68.9 ± 13 years in the sample. Bivariate relationships between all predictors and the seizures (dichotomously coded) were estimated to investigate the risk factors. The following were the significant predictors of seizures: male sex (17%; P = 0.014), dementia (27%; P = 0.012), and concomitant use of β-lactams, aminoglycosides, or fluoroquinolones (19.6%; P = 0.042).

CONCLUSION AND RELEVANCE

The currently approved ertapenem dose imposes a risk of developing neurotoxicity in patients with CKD-5D. Utilizing the published data in this population, alternative post-dialysis dosing strategies administered through dialysis access such as 1 g loading dose, followed by either 0.5 g (for the 48 hours interdialytic time) or 1 g (for the 72 hours interdialytic time) might warrant further investigation for efficacy and safety.

Reversing resistance: The next generation antibacterials

Irrational antibiotic usage has led to vast spread resistance to available antibiotics, but we refuse to slide back to “preantibiotic era.” The threat is serious with the “Enterococcus, Staphylococcous, Klebsiella, Acinetobacter, Pseudomonas and Enterobacter” organisms causing nosocomial infections that are difficult to treat because of the production of extended spectrum β-lactamases, carbapenamases and metallo-β-lactamases. Facing us is a situation where soon multidrug resistance would have spread across the globe with no antibiotics to withstand it. The infectious disease society of America and Food and Drug Administration have taken initiatives like the 10 × ‘20 where they plan to develop 10 new antibiotics by the year 2020. Existing classes of antibiotics against resistant bacteria include the carbapenems, oxazolidinones, glycopeptides, monobactams, streptogramins and daptomycin. Newer drugs in existing classes of antibiotics such as cephalosporins, aminoglycosides, tetracyclines, glycopeptides and β-lactamase inhibitors continue to get synthesized. The situation demands newer targets against bacterial machinery. Some of them include the peptidoglycantransferase, outer membrane protein of Pseudomonas, tRNA synthase, fatty acid synthase and mycobacterial ATP synthase. To curb the irrational and excessive usage of presently available antibiotics should be a priority if they are still to be kept in usage for the future.

Nosocomial extended-spectrum beta-lactamase-producing Klebsiella pneumoniae bacteremia in hemodialysis patients and the implications for antibiotic therapy

BACKGROUND

In the face of increasing treatment options for extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) hemodialysis (HD) access-related bacteremia, the difference in clinical effectiveness between ertapenem and flomoxef remains unclear. We conducted this retrospective study to determine their efficacies and treatment outcomes.

METHODS

Patients on maintenance HD with fistula-, graft-, or catheter-related ESBL-Kp bacteremia were enrolled. Data related to clinical features and antibiotic treatments were collected. Outcome was determined by mortality resulting from bacteremia during the 14-day period after the collection of the first positive blood culture for flomoxef-susceptible ESBL-Kp.

RESULTS

The 64 patients studied had severe septicemia as determined by the Pitt bacteremia score; 50% (32/64) were in the intensive care unit (ICU) at the time of bacteremia. Old age (>65 years; 57.8%), malnutrition (albumin<3.5g/dl; 92.2%), a history of severe illnesses (defined by shock, intubation, or ICU stay; 82.5%), and prolonged hospitalization prior to the onset of bacteremia (>30 days; 75%) were also highly prevalent. The study population comprised nine fistula-, 10 graft-, and 45 HD catheter-related bacteremia cases, and the mortality rate was high (38/64, 59.4%). The mortality rate was significantly higher in the flomoxef treatment group than in the ertapenem treatment group (22/30, 73% vs. 16/34, 47%, p<0.05). Among patients with catheter-related bacteremia, multivariate analyses revealed that flomoxef use (odds ratio (OR) 2.52, 95% confidence interval (CI) 1.34-35.17) and Pitt bacteremia score (OR 4.37, 95% CI 1.28-5.26) were independently associated with mortality.

CONCLUSIONS

In accordance with our previous study, our results have demonstrated the inferiority of flomoxef to carbapenems in the treatment of HD access-related ESBL-Kp bacteremia and provide an insight into the possibility of using ertapenem rather than flomoxef as an initial or de-escalating therapy for infections caused by ESBL-producing bacteria.

Efficacy of ertapenem for treatment of bloodstream infections caused by extended-spectrum-β-lactamase-producing Enterobacteriaceae

Ertapenem is active against extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae organisms but inactive against Pseudomonas aeruginosa and Acinetobacter baumannii. Due to a lack of therapeutic data for ertapenem in the treatment of ESBL bloodstream infections (BSIs), group 2 carbapenems (e.g., imipenem or meropenem) are often preferred for treatment of ESBL-producing Enterobacteriaceae, although their antipseudomonal activity is unnecessary. From 2005 to 2010, 261 patients with ESBL BSIs were analyzed. Outcomes were equivalent between patients treated with ertapenem and those treated with group 2 carbapenems (mortality rates of 6% and 18%, respectively; P = 0.18).

Beta-lactams and beta-lactamase-inhibitors in current- or potential-clinical practice: a comprehensive update

The use of successive generations of beta-lactams has selected successive generations of beta-lactamases including CTX-M ESBLs, AmpC beta-lactamases, and KPC carbapenamases in Enterobacteriaceae. Moreover, this cephalosporin resistance, along with rising resistance to fluoroquinolones, is now driving the use of carbapenems and unfortunately the carbapenem resistance has emerged markedly, especially in Acinetobacter spp. due to OXA- and metallo-carbapenemases. The industry responded to the challenge of rising resistance and recently developed some novel beta-lactams such as ceftobiprole, ceftaroline etc. and many beta-lactam compounds, including beta-lactamase-inhibitors, such as BMS-247243, S-3578, RWJ-54428, CS-023, SMP-601, NXL 104, BAL 30376, LK 157, and so on are under trials. This review provides the comprehensive accounts of the developments in penicillins, cephalosporins, carbapenems, and beta-lactamase-inhibitors, and the insight about medicinal chemistry, mechanism(s) of action and resistance, potential strategies to overcome resistance due to beta-lactamases, and also the recent advancements in the development of newer beta-lactam compounds; some of which are still under trials and yet to be classified. This review will fill the gap since previously published reviews and will serve as a comprehensive update on the current topic.

Safety profile of meropenem: an updated review of over 6,000 patients treated with meropenem

Meropenem is a broad-spectrum carbapenem antibacterial with potent antimicrobial activity against a broad range of Gram-negative, Gram-positive and anaerobic bacteria. The second parenteral carbapenem to be introduced worldwide, meropenem has been in clinical use since 1994. Two previous safety reviews have established that meropenem has a favourable and acceptable safety profile. This new review was conducted after the approval of meropenem in the US in 2005 for the treatment of patients with complicated skin and skin-structure infections, in addition to the previously approved indications of intra-abdominal infections and paediatric bacterial meningitis. The analysis includes the clinical trial data from the previous safety reviews, updated with expanded experience across a number of serious bacterial infections, including a large international study in patients with skin or skin-structure infections and further experience in patients with intra-abdominal infections and bacterial meningitis. A total of 6154 patients with 6308 meropenem exposures were compared with 4483 patients treated with comparator agents (4593 exposures), and the paediatric population base for which safety data are available has doubled to over 1000 patients. The data presented reinforce the favourable safety profile of meropenem. In general, the incidence and pattern of adverse events occurring with meropenem were similar to those of the first carbapenem, imipenem/cilastatin, and to those of the cephalosporin- and clindamycin-based regimens to which it had been compared. The most common adverse events reported for meropenem were diarrhoea (2.5%), rash (1.4%) and nausea/vomiting (1.2%). No adverse event occurred in more than 3% of patient exposures to meropenem, indicating a low overall frequency of adverse events as well as excellent gastrointestinal tolerability. Furthermore, no unexpected adverse events were identified, and the very low incidence of seizures in patients with meningitis was not considered to be drug related. In infections other than meningitis, the incidence of seizures considered by investigators to be related to meropenem treatment was 0.07%. In the new studies that updated the earlier safety data, no new cases of drug-related seizure were reported for any treatment or patient group (meningitis/non-meningitis infections). In conclusion, meropenem is well tolerated and has good CNS and gastrointestinal tolerability when used for the treatment of serious bacterial infections in a wide range of adult and paediatric patient populations.

Comparative pharmacokinetics and pharmacodynamic target attainment of ertapenem in normal-weight, obese, and extremely obese adults

Little is known of the effects of obesity on ertapenem drug disposition and pharmacodynamics. Thirty healthy volunteers in three body mass index (BMI) groups (10 per group), normal weight (BMI, 18.5 to 24.9 kg/m2), class I-II obesity (BMI, 30 to 39.9 kg/m2), and class III obesity (BMI, >or=40 kg/m2), were administered a 1-g dose of ertapenem. Serum concentrations were obtained over 24 h. Population pharmacokinetic data were obtained using a nonparametric adaptive grid followed by Monte Carlo simulation to determine the probability of obtaining the free drug exposure targets of the time that the free drug concentration remains above the MIC (fT>MIC) of 20% and 40% for bacteriostatic and maximal bactericidal activity, respectively. Compared to the subjects in the obese groups, area under the concentration-time curve from 0 h to infinity was significantly higher in the normal-weight subjects, whereas the total central compartment volume was higher in the class III obese subjects (P<or=0.05). Achieving a bacteriostatic target of fT>MIC of 20% with a 90% probability was attained at MICs of <or=0.5 microg/ml for normal-weight subjects. Class I-II and class III obese subjects were able to achieve this target only at a MIC of <or=0.25 microg/ml. For maximal bactericidal activity (fT>MIC, 40%), no group attained the target at the 90% probability level at any tested MIC. The results suggest that the standard 1-g ertapenem dose may not provide adequate drug exposure for any body mass index classification for MICs in excess of 0.25 to 0.5 microg/ml.

Ertapenem: a review of its use in the treatment of bacterial infections

The Group 1, 1 beta-methyl carbapenem ertapenem (Invanz) is approved for parenteral use in patients with complicated intra-abdominal infection (cIAI), community-acquired pneumonia (CAP) and acute pelvic infection caused by susceptible strains of certain designated organisms in both the US and the EU. Additional approved indications in the US include complicated skin and skin structure infection (cSSSI) and complicated urinary tract infection (cUTI). Ertapenem is approved for use in adults in both the US and the EU and in paediatric patients aged >or=3 months in the US. Ertapenem has a broad spectrum of in vitro activity against Gram-negative pathogens, including extended-spectrum beta-lactamase (ESBL)- and AmpC-producing Enterobacteriaceae, Gram-positive pathogens and anaerobic pathogens. It has similar efficacy to comparator antibacterials such as piperacillin/tazobactam in cSSSI (including diabetic foot infection), cIAI and acute pelvic infection and ceftriaxone with or without metronidazole in cIAI, cUTI and CAP. The drug has also shown efficacy in the treatment of paediatric patients with complicated community-acquired bacterial infections. Ertapenem has a convenient once-daily administration schedule and is generally well tolerated. Thus, ertapenem is an important option for the empirical treatment of complicated community-acquired bacterial infections in hospitalised patients.

Quantification of the carbapenem antibiotic ertapenem in human plasma by a validated liquid chromatography–mass spectrometry method

BACKGROUND

Ertapenem (Invanz) is a newly developed carbapenem beta-lactam antibiotic. LC-MS is the method of choice for therapeutic drug monitoring (TDM) of a variety of drugs including antibiotics. No validated LC-MS method for ertapenem quantification is described in the literature so far.

METHODS

A rapid and robust LC-MS quantification method for ertapenem was developed and validated for clinical routine application in plasma samples. After immediate stabilisation with MES buffer (pH 6.5), samples were prepared for LC-MS analysis using simple protein precipitation. LC-MS coupling was realised by the use of a Phenomenex Synergi 4micro Polar-RP A80 Mercury LC column (10 x 2.0 mm) in combination with a Single-MS (Agilent 1100 LC-MSD SL) operating in negative selected ion monitoring (SIM) detection mode with ceftazidime as internal standard for adequate selective and sensitive analysis.

RESULTS

LC-MS method validation by means of determination of limit of detection (LOD 0.1 microg mL-1), lower limit of quantification (LLOQ 1 microg mL-1), linearity (0.1-50 microg mL-1), recovery (> 90%), intra- and inter-day precision (RSD < 10%), accuracy (> 90%), inter-subject variability (< 10% at LLOQ), drug stability in plasma (> 3 months) and in post-extracted samples (> 99% for 24 h), and matrix effects (process efficiency > 90%) showed excellent performance parameters considering Guidance for Industry - Bioanalytical Method Validation.

CONCLUSION

This method is perfectly appropriate for routine quantification of ertapenem and possibly other polar carbapenem beta-lactam antibiotics.

Ertapenem: review of a new carbapenem

The carbapenems are beta-lactam-type antibiotics with an exceptionally broad spectrum of activity. Ertapenem is a new carbapenem developed to address the pharmacokinetic shortcomings (short half-life) of imipenem and meropenem. Ertapenem shares similar structural features with meropenem, including its stability to dehydropeptidase-1, allowing it to be administered without a dehydropeptidase-1 inhibitor. Ertapenem, like imipenem and meropenem, demonstrates broad-spectrum antimicrobial activity against many Gram-positive and -negative aerobes and anaerobes and is resistant to nearly all beta-lactamases, including extended-spectrum beta-lactamases and AmpCs. However, it differs from both imipenem and meropenem in demonstrating limited activity against Enterococcusspp., Pseudomonasaeruginosa and other nonfermentative Gram-negative bacteria commonly associated with nosocomial infections. The extensive protein binding of ertapenem extends the half-life and allows for once-daily dosing. Prospective, multicenter, randomized, double-blind, comparative clinical studies demonstrate similar clinical efficacy of ertapenem compared with other agents. Clinical trials of complicated intra-abdominal infection, acute pelvic infection, complicated skin and soft-structure infection, community-acquired pneumonia and complicated urinary tract infections demonstrated that ertapenem has equivalent efficacy and safety compared with ceftriaxone and piperacillin/tazobactam. Ertapenem is a promising new carbapenem with excellent efficacy and safety for the treatment of a variety of community-acquired infections. It also appears to be of great value as an outpatient parenteral antimicrobial therapy.

Ertapenem-Associated Seizures in a Peritoneal Dialysis Patient

OBJECTIVE:

To report a case of a patient undergoing peritoneal dialysis who developed refractory seizures after 2 doses of ertapenem.

CASE SUMMARY:

A 56-year-old white man with end-stage renal disease requiring continuous ambulatory peritoneal dialysis experienced 5 seizures following 2 doses of ertapenem 500 mg given intravenously. The first generalized tonic—clonic seizure occurred 16 hours after the second ertapenem dose and lasted 3 minutes. Three hours after his first seizure, the patient experienced 2 more seizures 15 minutes apart, lasting 3 minutes each. After suffering a fifth seizure, the patient became apneic and pulseless and was not resuscitated, as he had previously requested a “do not resuscitate” status.

DISCUSSION:

Carbapenem treatment has been associated with simple partial, complex partial, and generalized tonic—clonic seizures, with generalized seizures representing the most frequently occurring type. Safety data from 7 published clinical trials of ertapenem revealed a seizure incidence of 0.18%. To our knowledge, there are no previously published reports of ertapenem neurotoxicity in patients undergoing peritoneal dialysis. Moreover, little information is available regarding the pharmacokinetics of carbapenems in end-stage renal disease. Ertapenem pharmacokinetics were not tested in any patients receiving peritoneal dialysis during published clinical trials.

CONCLUSIONS:

Our patient experienced 5 seizures, possibly induced by ertapenem, as validated by the Naranjo probability scale. Clinicians administering ertapenem to patients undergoing peritoneal dialysis should use caution, as clinical experience with the agent is limited and pharmacokinetic data are lacking.

Ertapenem versus ceftriaxone and metronidazole as treatment for complicated intra-abdominal infections

BACKGROUND

Prompt surgical intervention supplemented by appropriate antimicrobial therapy is usually required for successful treatment of complicated intra-abdominal infections. The objective of this study was to further evaluate the efficacy and safety of ertapenem relative to ceftriaxone/metronidazole as treatment for complicated intra-abdominal infections.

METHODS

Adult patients with intra-abdominal infections requiring surgery were eligible for this open-label randomized trial comparing ertapenem 1 g daily with ceftriaxone 2 g daily plus metronidazole 30 mg/kg/day. The primary efficacy outcome was the clinical response rate in clinically and microbiologically evaluable participants at the test-of-cure (TOC) visit 2 weeks after discontinuation of therapy. All treated patients were included in the safety analysis.

RESULTS

Participant demographics, disease characteristics, and duration of therapy in both treatment groups were generally similar. Escherichia coli was the most commonly isolated baseline pathogen, recovered in 52% of cases in each treatment group. Favorable clinical responses were achieved at TOC in 143 (96.6%) of 148 ertapenem recipients and in 146 (96.7%) of 151 ceftriaxone/metronidazole recipients. The frequencies of drug-related adverse events, most commonly nausea, diarrhea, vomiting, and elevated platelet count, were generally comparable in both treatment arms. Four ertapenem recipients (1.8%) and one ceftriaxone/metronidazole recipient (0.4%) experienced serious drug-related adverse events.

CONCLUSIONS

In this study, ertapenem and ceftriaxone/metronidazole were comparably effective treatments for adult patients with complicated intra-abdominal infections.

Ertapenem pharmacokinetics and impact on intestinal microflora, in comparison to those of ceftriaxone, after multiple dosing in male and female volunteers

The pharmacokinetics of ertapenem and ceftriaxone were investigated in an open, randomized, two-period crossover study after single- and multiple-dose administration in 10 healthy volunteers (five women and five men). Both antibiotics were administered intravenously once daily for 7 days at dosages of 1 g (ertapenem) and 2 g (ceftriaxone). The concentrations of the antibiotics in serum and urine were quantified by the agar well diffusion method bioassay and, in addition, for ertapenem only, by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). For ertapenem the maximum concentration of the drug in plasma (C(max)) was 256 mg/liter, the half-life was 20.7 h, and the area under the plasma concentration-time curve (AUC) was 830 mg. h/liter. The concentrations in fecal samples were (mean value) 37.2 and 32.7 mg/kg on day 4 and day 8, respectively. Ceftriaxone exhibited a mean C(max) of 315 mg/liter, a half-life of 7.6 h, and an AUC of 1,556 mg. h/liter. The mean concentrations in fecal samples were 153 and 258 mg/kg on day 4 and day 8, respectively. No accumulation of ertapenem or ceftriaxone was detected at steady state. A slightly but significantly decreased AUC for ertapenem was detected for the female volunteers. No serious adverse event was observed. Both antibiotics induced a marked decrease in the anaerobic microflora (4-log-unit decreases in lactobacilli, bifidobacteria, clostridia, and bacteroides) and Escherichia coli, whereas the number of enterococci increased (4 log units). A slight overgrowth of yeasts was observed with both regimens. In all cases the microflora returned to normal levels on days 21 to 35.