Epileptogenic potential of carbapenem agents: mechanism of action, seizure rates, and clinical considerations

Ertapenem blood concentration: A retrospective cohort study to analyse risk of neurotoxicity

AIMS

Several cases of ertapenem-related neurotoxicity have been published in the current literature. However, studies evaluating the ertapenem blood concentration (EBC) as a risk of these adverse events are scarce. We aimed to evaluate the relationship between the trough EBC and the risk of neurological toxicity.

METHODS

This was a retrospective study, including patients who underwent ertapenem treatment between October 2019 and February 2021. We excluded patients in the critical care unit and those whose blood samples were not properly taken in order to analyse ertapenem trough concentration. We also excluded patients whose clinical follow-up was not properly realized for the entire period of ertapenem treatment. The main outcome was the presence of any suspicious neurological side effect owing to ertapenem administration and its relationship with the plasma concentration. Secondary outcomes were to identify clinical and analytical data contributing to a higher risk of neurotoxicity.

RESULTS

The initial cohort comprised 158 individuals. For the final analysis we evaluated 102 patients, reporting a neurological alteration in 13/102 (12.7%). Mean trough EBC was significantly higher in patients showing neurotoxicity in comparison with those who did not (37.8 mcg mL-1 , standard deviation [SD] ± 35.7 vs. 14.6 mcg mL-1 , SD ± 15.2; P = .002). In multivariable logistic regression analysis, EBC (odds ratio [OR] = 1.07; P = .006), a moderate renal insufficiency (OR = 9.2; P = .02) and a history of previous neurologic disease (OR = 9.9; P = .02) were identified as risk factors of neurological alteration during ertapenem treatment.

CONCLUSIONS

In patients at risk, determining the ertapenem plasma concentration may help to minimize the risk of neurotoxicity.

Seizures associated with antibiotics: a real-world disproportionality analysis of FAERS database

BACKGROUND

Drug-induced seizures are a common occurrence in clinical practice, with research indicating that around 6% of initial seizures are due to drug toxicity. The use of antibiotics is one such cause of drug-related seizures. Previous systematic review has identified specific antibiotics that pose a risk of seizures, but a comprehensive analysis of a large patient sample is needed to determine the risk associated with various drugs.

OBJECTIVE

This study aimed to evaluate the association between seizures and various antibiotics that are presently accessible.

METHODS

To identify potential risk signals from the US Food and Drug Administration adverse event reporting system (FAERS) database, a disproportionality analysis was conducted. The reporting odds ratio (ROR) using the frequency approach and the information component (IC) using the Bayesian approach were used to detect signals. The median time-to-onset of seizure, as well as the Weibull distribution parameters were calculated to analyze the onset time.

RESULTS

A total of 14,407,157 FAERS reports were analyzed.10 antibiotics were associated with seizures that were defined by 41 preferred terms. Onset time were aligned with the wear out failure type profile.

CONCLUSION

This study identified 10 antibiotics that showed significant associations with seizures. Imipenem-cilastatin had the highest seizure ROR.

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.

Altered EEG, disrupted hippocampal long-term potentiation and neurobehavioral deficits implicate a delirium-like state in a mouse model of sepsis

Sepsis and systemic inflammation are often accompanied by severe encephalopathy, sleep disruption and delirium that strongly correlate with poor clinical outcomes including long-term cognitive deficits. The cardinal manifestations of delirium are fluctuating altered mental status and inattention, identified in critically ill patients by interactive bedside assessment. The lack of analogous assessments in mouse models or clear biomarkers is a challenge to preclinical studies of delirium. In this study, we utilized concurrent measures of telemetric EEG recordings and neurobehavioral tasks in mice to characterize inattention and persistent cognitive deficits following polymicrobial sepsis. During the 24-hour critical illness period for the mice, slow-wave EEG dominance, sleep disruption, and hypersensitivity to auditory stimuli in neurobehavioral tasks resembled clinical observations in delirious patients in which alterations in similar outcome measurements, although measured differently in mice and humans, are reported. Mice were tested for nest building ability 7 days after sepsis induction, when sickness behaviors and spontaneous activity had returned to baseline. Animals that showed persistent deficits determined by poor nest building at 7 days also exhibited molecular changes in hippocampal long-term potentiation compared to mice that returned to baseline cognitive performance. Together, these behavioral and electrophysiological biomarkers offer a robust mouse model with which to further probe molecular pathways underlying brain and behavioral changes during and after acute illness such as sepsis.

Community-acquired pneumonia - An EFIM guideline critical appraisal adaptation for internists

BACKGROUND

In real-life settings, guidelines frequently cannot be followed since many patients are multimorbid and/or elderly or have other complicating conditions which carry an increased risk of drug-drug interactions. This document aimed to adapt recommendations from existing clinical practice guidelines (CPGs) to assist physicians' decision-making processes concerning specific and complex scenarios related to acute CAP.

METHODS

The process for the adaptation procedure started with the identification of unsolved clinical questions (PICOs) in patients with CAP and continued with critically appraising the updated existing CPGs and choosing the recommendations, which are most applicable to these specific scenarios.

RESULTS

Seventeen CPGs were appraised to address five PICOs. Twenty-seven recommendations were endorsed based on 7 high, 9 moderate, 10 low, and 1 very low-quality evidence. The most valid recommendations applicable to the clinical practice were the following ones: Respiratory virus testing is strongly recommended during periods of increased respiratory virus activity. Assessing the severity with a validated prediction rule to discriminate where to treat the patient is strongly recommended along with reassessing the patient periodically for improvement as expected. In adults with multiple comorbidities, polypharmacy, or advanced age, it is strongly recommended to check for possible drug interactions before starting treatment. Strong graded recommendations exist on antibiotic treatment and its duration. Recommendations on the use of biomarkers such as C-reactive protein or procalcitonin to improve severity assessment are reported.

CONCLUSION

This document provides a simple and reliable updated guide for clinical decision-making in the management of complex patients with multimorbidity and CAP in the real-life setting.

Antimicrobial safety considerations in critically ill patients: part II: focused on anti-microbial toxicities

INTRODUCTION

Antibiotic prescription is a challenging issue in critical care settings. Different pharmacokinetic and pharmacodynamic properties, polypharmacy, drug interactions, and high incidence of multidrug-resistant microorganisms in this population can influence the selection, safety, and efficacy of prescribed antibiotics.

AREAS COVERED

In the current article we searched PubMed, Scopus and Google Scholar for neurotoxicities, hematologic toxicity and fluid stewardship in intensive care units.

EXPERT OPINION

Critically ill patients who receive antimicrobial agents should be monitored for neurological, hematologic toxicities especially seizure, thrombocytopenia, and clostridioides infections. Other toxicities including QTc prolongation, electrolyte disturbances, liver enzyme elevation, and infusion-related reactions were being considered. Other changes, including fluid overload, hypoalbuminemia, augmented renal clearance, increased cardiac outputs in septic shock, and acute kidney injury, may influence treatment efficiency and patient outcome.

Probable ertapenem-induced encephalopathy; case report and suggested alternatives for chronic prostatitis

Ertapenem is a carbapenem antibiotic usually reserved for complicated infections. Drug-induced neurotoxicity is a rare adverse reaction associated with ertapenem, and may be directly related to its chemical structure. We report a case of a 64-year-old male with a hematological history and chronic prostatitis that was admitted to hospital for gait instability, clumsiness, dysarthria and tremors. He started ertapenem intravenous 1 g once daily a week prior to admission. Creatinine clearance calculation by the Cockcroft-Gault method was 52 mL/min and total protein levels were low. Ertapenem's administration was discontinued and the patient's neurological symptoms improved dramatically just one day after. The result of the Naranjo Scale was six, suggesting a probable adverse drug reaction. We discussed if he could receive meropenem in case of severe infection such as septic shock. Considering the patient's medical history, the chemical structure of meropenem and the fact that there are almost no reported cases of neurotoxicity from this drug, we assume that meropenem could be used in case of severe infection in patients with history of neurotoxicity caused by ertapenem if no added risk factors are present, such as renal failure.

Pharmacokinetics of benapenem for injection in subjects with mild to moderate renal impairment

OBJECTIVE

This study evaluated the pharmacokinetic (PK) characteristics of benapenem in subjects with mild to moderate renal impairment to provide a reference for benapenem dosing regimens in this patient population.

METHODS

Eighteen subjects were enrolled in this study. Each subject received a single dose of benapenem intravenously (1.0 g in 100 ml of 0.9% saline) followed by blood and urine collection to measure the concentrations of benapenem and its major metabolite. PK analysis was performed to evaluate the effect of varying degrees of renal impairment on the PK characteristics of benapenem. The safety of benapenem was also evaluated.

RESULTS

In subjects with normal renal function, mild renal impairment, and moderate renal impairment, the maximum plasma benapenem concentrations were 163 ± 6.58 mg/L, 138 ± 17.4 mg/L, and 134 ± 0.11 mg/L, respectively (15.3% and 17.8% lower in subjects with mild and moderate renal impairment, respectively, than in subjects with normal renal function). The areas under the plasma concentration-time curve (AUC_0-inf) were 1153.67 ± 143.2 mg·h/L, 1129.17 ± 241.41 mg·h/L, and 1316.46 ± 229.83 mg·h/L, respectively (P > 0.05); the cumulative urinary excretion rates at 72 h after dosing were 52.61 ± 8.58%, 39.42 ± 8.35%, and 29.84 ± 9.15%, respectively; and the metabolic ratio (AUC_0-inf__KBP-3331/AUC_0-inf__benapenem) were 3.96 ± 0.35%, 5.56 ± 0.82%, and 8.24 ± 0.85%, respectively. No drug-related adverse events (AEs), serious AEs, or AEs leading to withdrawal occurred in this study.

CONCLUSION

No adjustment to benapenem dosing is needed in patients with mild to moderate renal impairment.

CLINICAL TRIAL REGISTRATION

Drug clinical trial registration and information publicity platform: http://www.chinadrugtrials.org.cn/index.html .

REGISTRATION NUMBER

CTR20190760.

Probable Encephalopathy and Spasticity in a Multiple Sclerosis Patient Following Carbapenem Administration: A Case Report and Brief Literature Review

Purpose: The purpose of this case report is to describe spasticity and encephalopathy that developed in a multiple sclerosis patient following carbapenem administration. Summary: A 55-year-old female with multiple sclerosis developed spasticity and encephalopathy within 24 hours of meropenem and ertapenem administration. This was the second time that she had developed encephalopathy following carbapenem administration. The patient gradually recovered over four days following discontinuation of carbapenem therapy. Conclusion: Carbapenem neurotoxicity, a well-documented adverse effect, has been linked to several risk factors, including central nervous system lesions. Despite this, there is little evidence describing the risk of neurotoxicity in patients with multiple sclerosis. It is important to understand the potential adverse effects of carbapenems in specific patient populations to help guide appropriate treatment of infections.

Antibiotics and the Nervous System-Which Face of Antibiotic Therapy Is Real, Dr. Jekyll (Neurotoxicity) or Mr. Hyde (Neuroprotection)?

Antibiotics as antibacterial drugs have saved many lives, but have also become a victim of their own success. Their widespread abuse reduces their anti-infective effectiveness and causes the development of bacterial resistance. Moreover, irrational antibiotic therapy contributes to gastrointestinal dysbiosis, that increases the risk of the development of many diseases, including neurological and psychiatric. One of the potential options for restoring homeostasis is the use of oral antibiotics that are poorly absorbed from the gastrointestinal tract (e.g., rifaximin alfa). Thus, antibiotic therapy may exert neurological or psychiatric adverse drug reactions which are often considered to be overlooked and undervalued issues. Drug-induced neurotoxicity is mostly observed after beta-lactams and quinolones. Penicillin may produce a wide range of neurological dysfunctions, including encephalopathy, behavioral changes, myoclonus or seizures. Their pathomechanism results from the disturbances of gamma-aminobutyric acid-GABA transmission (due to the molecular similarities between the structure of the β-lactam ring and GABA molecule) and impairment of the functioning of benzodiazepine receptors (BZD). However, on the other hand, antibiotics have also been studied for their neuroprotective properties in the treatment of neurodegenerative and neuroinflammatory processes (e.g., Alzheimer's or Parkinson's diseases). Antibiotics may, therefore, become promising elements of multi-targeted therapy for these entities.

Drug-Induced Seizures: Considerations for Underlying Molecular Mechanisms

A broad spectrum of chemical entities have been associated with drug-induced seizure (DIS), emphasizing the importance of this potential liability across various drug classes (e.g., antidepressants, antipsychotics, antibiotics, and analgesics among others). Despite its importance within drug safety testing, an understanding of the molecular mechanisms associated with DIS is often lacking. The etiology of DIS is understood to be a result of either a deficit in inhibitory (e.g., gamma aminobutyric acid) or an elevated excitatory (e.g., glutamate) signaling, leading to synchronous neuronal depolarization affecting various brain regions and impairing normal neurological functions. How this altered neuronal signaling occurs and how these changes interact with other non-brain receptor driven DIS-associated changes such as metabolic disturbances, electrolyte imbalances, altered drug metabolism, and withdrawal effects are poorly understood. Herein, we discuss important molecular mechanisms identified in DIS for several drugs and/or drug classes. With a better understanding of the molecular mechanisms associated with DIS, in vivo or in vitro models may be applied to characterize and mitigate DIS risk during drug development. Susceptibility stratification for DIS presents species differences in the following order beagle dogs > rodents and cynomolgus monkeys > Göttingen minipigs with a more than 2-fold difference between canines and minipigs, which is important to consider during non-clinical species selection. While clinical signs such as myoclonus, severe muscle jerks, or convulsions are often associated with abnormal epileptiform EEG activity, tremors are most of the time physiological and rarely observed with concurrent epileptiform EEG activity which need to be considered during DIS risk evaluation.

Epileptic Seizures After Allogeneic Hematopoietic Stem Cell Transplantation

Technique in allogeneic hematopoietic stem cell transplantation has greatly advanced over the past decades, which has led to an increase in the number of patients receiving transplantation, but the complex procedure places these transplant recipients at high risk of a large spectrum of complications including neurologic involvement. As a common manifestation of neurological disorders, epileptic seizures after transplantation have been of great concern to clinicians because it seriously affects the survival rate and living quality of those recipients. The aim of this review is to elucidate the incidence of seizures after allogeneic hematopoietic stem cell transplantation, and to further summarize in detail its etiologies, possible mechanisms, clinical manifestations, therapeutic schedule, and prognosis, hoping to improve doctors' understandings of concurrent seizures following transplantation, so they can prevent, process, and eventually improve the survival and outlook for patients in a timely manner and correctly.

Activity of imipenem/relebactam against Pseudomonas aeruginosa producing ESBLs and carbapenemases

BACKGROUND

ESBL- and carbapenemase-producing Pseudomonas aeruginosa are prevalent in, for example, the Middle East, Eastern Europe and Latin America, though rarer elsewhere. Because P. aeruginosa readily mutate to become carbapenem resistant via loss of OprD, isolates producing ESBLs are often as broadly resistant as those producing carbapenemases. We hypothesized that: (i) relebactam might overcome class A carbapenemases directly in P. aeruginosa; and (ii) relebactam's inhibition of AmpC, which gives a generalized potentiation of imipenem against the species, might restore imipenem susceptibility in OprD-deficient ESBL producers.

METHODS

MICs were determined using CLSI agar dilution for P. aeruginosa isolates producing ESBLs, principally VEB types, and for those producing GES-5, KPC and other carbapenemases.

RESULTS

Relebactam potentiated imipenem by around 4-8-fold for most P. aeruginosa isolates producing VEB and other ESBLs; however, MICs were typically only reduced to 4-16 mg/L, thus mostly remaining above EUCAST's susceptible range and only partly overlapping CLSI's intermediate range. Strong (approx. 64-fold) potentiation was seen for isolates producing KPC carbapenemases, but only 2-fold synergy for those with GES-5. Predictably, potentiation was not seen for isolates with class B or D carbapenemase activity.

CONCLUSIONS

Relebactam did potentiate imipenem against ESBL-producing P. aeruginosa, which are mostly imipenem resistant via OprD loss, but this potentiation was generally insufficient to reduce imipenem MICs to the clinical range. Imipenem resistance owing to KPC carbapenemases was reversed by relebactam in P. aeruginosa, just as for Enterobacterales.

Pharmacist intervention to improve patients' knowledge and attitude towards hepatitis B infection

OBJECTIVE

Lack of knowledge/awareness of people living with hepatitis B (PLH) often leads to misinformation and stigmatisation. This study aimed to assess the contribution of the clinical pharmacist (CP)-led education on knowledge of PLH about their disease.

METHODS

This prospective, cross-sectional study was carried out between 1 October 2017 and 1 April 2018, at infectious disease and gastroenterology outpatient clinics in a university hospital. All PLH were interviewed face-to-face by a CP and a questionnaire about hepatitis B virus (HBV) knowledge was applied both at the beginning of the study (first interview) and 3 months later (second interview). Correct information was provided verbally to the patients by the CP concerning their incorrect answers during the first interview. A 10% increase in the number of correct answers was targeted for the second interview.

RESULTS

A total of 147 PLH with a mean age of 43.05 ± 13.25 years were included in the study (55.8% female). In the first interview, the mean (±standard deviation) number of correct answers was 35.53 ± 9.15 out of 51 questions. In the second interview, correct answers were 48.67 ± 2.74 with an increase of 25.8% (P < .001). In the first interview, the number of correct answers was higher for the following groups: 20-39 age group, people with monthly income of >1081 $ and university graduates. The number of correct answers to all questions but one was elevated (P < .001) in the second interview. Answers to the question "there is a carrier state in chronic hepatitis B (CHB)" did not change (P = .125).

CONCLUSION

Significant improvement was observed in the correct answer rate after CP's contribution, therefore as a team member, CP has an important role in improving patients' knowledge and attitude towards HBV infection.

Ertapenem neurotoxicity in patients with kidney damage: A case report

Ertapenem, a member of the carbapenem group of antibiotics, is a broad-spectrum antibiotic that is effective against multidrug-resistant gram-positive and gram-negative infections. In patients with acute or chronic kidney damage, one of the most serious side effects of ertapenem is neurotoxicity. Various clinical conditions such as seizures, hallucinations, delirium, confusion, and nystagmus may occur. Previous history of cerebral pathologies is a known risk factor for ertapenem-associated neurotoxicity. Immediate discontinuation of treatment is required. Although the symptoms usually resolve rapidly, cases with longer duration of symptoms have also been reported. Close monitoring of neurological status in such patients is essential.

Effect of drug interactions between carbapenems and valproate on serum valproate concentration: a systematic review and meta-analysis

Background: Concurrent use of valproate and carbapenem antibiotics may decrease serum valproate concentration (SVC). This study evaluated the effects of carbapenem-valproate drug interactions. Research design and methods: We screened PubMed, EMBASE, and Cochrane databases for eligible prospective or retrospective studies that evaluated the effect of concurrent use of carbapenem and valproate compared with valproate alone on SVC. Primary outcomes were the change in SVC from before the addition of the carbapenem to the SVC during the use of carbapenems and after carbapenem discontinuation, and seizure-related outcomes. Secondary outcomes were the influence of valproate or carbapenem dose on SVC and Drug Interaction Probability Scale scores. Results: Twelve studies (633 patients) were included. Compared with valproate alone, combination treatment with carbapenem substantially decreased mean SVC (mean difference, -43.98 mg/L; 95% confidence interval, -48.18 to -39.78). The onset of SVC decreases was within 1-3 days following carbapenem initiation. Seizure frequency increased by 26.3% during combination treatment. No difference was found in mean SVC between the different doses of valproate or carbapenem during combination treatment. Mean SVC increased to similar pre-carbapenem level within 1 to 2 weeks after carbapenem discontinuation. Conclusions: The drug interaction between valproate and carbapenem causes substantial SVC decreases, even to subtherapeutic levels, which may increase the risk of seizures.

Meropenem at recommended dose is a potential risk for seizure in hemodialysis patient

Dosage adjustment of meropenem is usually recommended in hemodialysis (HD) patients and about 30% of meropenem is cleared during regular HD sessions. However, most of the published trials excluded patients on regular HD. Little is known about the accurate dosage of meropenem needed to avoid central nervous system toxicity. Herein, we report a 65-year-old Saudi female, a known case of end-stage renal disease on regular HD, who was admitted because of pyelonephritis and started on meropenem in the recommended dose according to cultures and sensitivity. She developed tonic-clonic convulsions after the 7^th dose. Seizures were completely aborted after discontinuation of the offending drug. The recommended dosage of 500 mg daily in HD patients may still be too high particularly in Asian patients owing to their relatively small body mass index.

Antibiotic-induced epileptic seizures: mechanisms of action and clinical considerations

In recent years, there has been growing interest in the development of epileptic seizures as an adverse effect of antibiotic therapy. The most commonly accepted mechanisms underlying the development of antibiotic-induced seizures include direct- and indirect gamma-aminobutyric acid (GABA) antagonism, inhibition of GABA synthesis, and glutaminergic N-methyl-D-Aspartate (NMDA) receptor agonistic activity. Inhibitory pathway inhibition leads to increased neuronal excitability and lowered seizure threshold. Blockage of myoneural presynaptic acetylcholine release, mitochondrial dysfunction, interference of neural protein synthesis, and oxidative stress caused by the generation of neurotoxic radicals also contributes to the development of neurotoxicity. Patients with pre-existing risk factors such as renal or hepatic insufficiency, central nervous system pathology, neurological diseases, history of epilepsy or seizures, critical illness, and increased age are more susceptible to seizure development as a consequence of antibiotic therapy. Administration of antibiotics, together with antiseizure drugs, may also lead to enhanced seizure risk due to drug interactions, which predisposes to alterations in drug metabolism and therapeutic efficacy.

Intraventricular Tigecycline as a Last Resort Therapy in a Patient with Difficult-to-Treat Healthcare-Associated Acinetobacter baumannii Ventriculitis: a Case Report

Healthcare-associated ventriculitis and meningitis is a common complication in patients who suffer from head trauma or have undergone a neurosurgery. Healthcare-associated ventriculitis and meningitis is associated with significant morbidity and mortality. Complications of healthcare-associated ventriculitis and meningitis include persistent vegetative state, moderate and severe disability, and death. Acinetobacter baumannii is the causative pathogen in 3.6–11.2% of cases of healthcare-associated ventriculitis and meningitis. Cases of difficult-to-treat healthcare-associated A. baumannii ventriculitis and meningitis are being reported more frequently. However, in most of these cases, a combination of intravenous (IV) and intraventricular (IVT)/intrathecal colistin achieves good therapeutic outcome. This report describes a clinical case of difficult-to-treat healthcare-associated A. baumannii ventriculitis. The A. baumannii strain was sensitive to colistin and trimethoprim-sulfamethoxazole, intermediate to tigecycline, and resistant to other antibiotics. While colistin was the drug of choice in our case, the patient developed anaphylactoid reaction during the IV administration of the loading dose of colistin, which mandated us to discontinue colistin and complicated the treatment of our patient. The patient did not respond to a combination of IV antibiotics that included meropenem, trimethoprim-sulfamethoxazole, and tigecycline. However, when IVT tigecycline was added as a last-resort therapeutic option, the patient’s ventriculitis dramatically improved, and the patient was discharged from the hospital. Physicians who treat patients with healthcare-associated A. baumannii ventriculitis might resort to IVT tigecycline when they run out of therapeutic options.

A Physiologically Based Pharmacokinetic Model of Ertapenem in Pediatric Patients With Renal Impairment

Ertapenem is a widely used antibiotic; however, its pharmacokinetics has not been fully evaluated in children with renal impairment. A physiologically based pharmacokinetic (PBPK) model of ertapenem was established and validated to simulate its disposition in the healthy population and adults with renal impairment, as well as to predict the exposure in pediatric patients with renal impairment. The simulated PBPK modeling results and the observed data of ertapenem after intravenous administration of various regimens were consistent according to the fold error values of less than 2. Furthermore, %T > MIC of ertapenem was evaluated using the PBPK model. The C_max was not significantly changed in pediatric patients with renal impairment compared to healthy children. However, the AUC was 1.42-fold, 1.84-fold, 2.37-fold, and 3.52-fold higher in mild, moderate, severe renal impairment, and end-stage renal disease, respectively, than that in healthy children and the doses of ertapenem were reduced to 13 mg/kg b.i.d, 9 mg/kg b.i.d, 6 mg/kg b.i.d, and 5 mg/kg b.i.d, respectively. The probability of achieving 40%T > MIC (MIC ≤ 4 μg/mL) was nearly 100% throughout the recommended dosing interval. In conclusion, our model can be used as a tool to generate better predictions for the most effective ertapenem dosing in pediatric patients.

Meropenem/vaborbactam: a next generation β-lactam β-lactamase inhibitor combination

INTRODUCTION

infections due to carbapenem-resistant Enterobacterales (CRE) constitute a worldwide threat and are associated with significant mortality, especially in fragile patients, and costs. Meropenem-vaborbactam (M/V) is a combination of a group 2 carbapenem with a novel cyclic boronic acid-based β-lactamase inhibitor which has shown good efficacy against KPC carbapenemase-producing Klebsiella pneumoniae, which are amongst the most prevalent types of CRE.

AREAS COVERED

This article reviews the microbiological and pharmacological profile and current clinical experience and safety of M/V in the treatment of infections caused by CRE.

EXPERT OPINION

M/V is a promising drug for the treatment of infections due to KPC-producing CRE (KPC-CRE). It exhibited an almost complete coverage of KPC-CRE isolates from large surveillance studies and a low propensity for resistance selection, retaining activity also against strains producing KPC mutants resistant to ceftazidime-avibactam. Both meropenem and vaborbactam have a favorable pharmacokinetic profile, with similar kinetic properties, a good intrapulmonary penetration, and are efficiently cleared during continuous venovenous hemofiltration (CVVH). According to available data, M/V monotherapy is associated with higher clinical cure rates and lower rates of adverse events, especially in terms of nephrotoxicity, if compared to 'older' combination therapies.

Imipenem-Cilastatin-Relebactam: A Novel β-Lactam-β-Lactamase Inhibitor Combination for the Treatment of Multidrug-Resistant Gram-Negative Infections

Imipenem-cilastatin-relebactam (IMI-REL) is a novel β-lactam-β-lactamase inhibitor combination recently approved for the treatment of complicated urinary tract infections (cUTIs) and complicated intraabdominal infections (cIAIs). Relebactam is a β-lactamase inhibitor with the ability to inhibit a broad spectrum of β-lactamases such as class A and class C β-lactamases, including carbapenemases. The addition of relebactam to imipenem restores imipenem activity against several imipenem-resistant bacteria, including Enterobacteriaceae and Pseudomonas aeruginosa. Clinical data demonstrate that IMI-REL is well tolerated and effective in the treatment of cUTIs and cIAIs due to imipenem-resistant bacteria. In a phase III trial comparing IMI-REL with imipenem plus colistin, favorable clinical response was achieved in 71% and 70% of patients, respectively. Available clinical and pharmacokinetic data support the approved dosage of a 30-minute infusion of imipenem 500 mg-cilastatin 500 mg-relebactam 250 mg every 6 hours, along with dosage adjustments based on renal function. In this review, we describe the chemistry, mechanism of action, spectrum of activity, pharmacokinetics and pharmacodynamics, and clinical efficacy, and safety and tolerability of this new agent. The approval of IMI-REL represents another important step in the ongoing fight against multidrug-resistant gram-negative pathogens.

Higher rates of carbapenem-related seizures in older hospitalised adults

Clinical experience suggests higher occurrence of carbapenem-associated seizures in the elderly than what is reported in the available literature (range between 0.2% and 0.7%). An audit of 1345 patients with age 60 years or older, who received imipenem, ertapenem or meropenem during their acute hospitalisation found 32 (2.4%) subjects developed seizures. Subjects with more than one central nervous system disorders were 11.6 times more likely to develop seizures (odds ratio 11.61, P < 0.001) and subjects with prior history of seizures is associated with four times greater risks (odds ratio 4.02, P = 0.005). Physicians should exercise caution when prescribing carbapenems in elderly, especially those with known epilepsy and a high number of intracranial pathologies.

Comparative efficacy of doripenem versus meropenem for hospital-acquired and ventilator-associated pneumonia

BACKGROUND

Doripenem shows good in vitro activity against common nosocomial pathogens, such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii. However, the use of doripenem for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) remains controversial. The aim of this study was to compare the efficacy and safety between doripenem and meropenem for patients with HAP or VAP.

METHODS

Adult patients diagnosed with HAP and VAP at National Taiwan University Hospital, who received doripenem or meropenem for more than 48 h between January 2015 and November 2017, were retrospectively reviewed. All-cause mortality on the 30th day was used as the primary outcome measurements.

RESULTS

Fifty-seven patients with doripenem and 252 patients with meropenem were analyzed. Compared to the meropenem group, the doripenem group was younger and had a higher Sequential Organ Failure Assessment (SOFA) score. Multivariable Cox regression analysis revealed that presence of solid organ malignancies (adjusted hazard ratio [AHR], 1.82; 95% CI, 1.04-3.19, p = 0.003) and SOFA score (AHR, 1.10; 95% CI, 1.03-1.17, p = 0.003) were independent factors associated with mortality. There was no survival difference of 30-day mortality between patients receiving doripenem and meropenem for HAP or VAP (log-rank p = 0.113). However, a poorer outcome was observed among patients with hematological disease in the doripenem group (log-rank p = 0.012).

CONCLUSION

Our results demonstrate that doripenem has similar efficacy as meropenem in HAP or VAP patients. With an aim to enhance antibiotic diversity, doripenem could be an alternative choice for patients with HAP or VAP, except for those with hematological malignancies.

Clinical Pharmacology of Antibiotics

Antimicrobial pharmacology and its effect on prescribing is quite complex. Selecting an antibiotic that will optimally treat an infection while minimizing adverse effects and the development of resistance is only the first step, as one must also consider the patient's individual pharmacokinetic alterations and the pharmacodynamic properties of the drug when prescribing it as well. Patients with CKD may have alterations in their protein binding, volumes of distribution, kidney clearance, and nonrenal clearance that necessitates antibiotic dose adjustments to prevent the development of toxicity. Knowledge of a drug's pharmacodynamics, defined as the relationship between drug exposure and antibacterial efficacy, provides some guidance regarding the optimal way to make dose adjustments. Different pharmacodynamic goals, such as maximizing the time that free (unbound) drug concentrations spend above the minimum inhibitory concentration (MIC) for time dependent drugs (e.g., β-lactams) or maximizing the free peak-to-MIC ratio for concentration-dependent antibiotics (e.g., aminoglycosides), require different adjustment strategies; for instance, decreasing the dose while maintaining normal dosing frequency or giving normal (or even larger) doses less frequently, respectively. Patients receiving hemodialysis have other important prescribing considerations as well. The nephrologist or patient may prefer to receive antibiotics that can be administered intravenously toward the end of a dialysis session. Additionally, newer dialysis technologies and filters can increase drug removal more than originally reported. This review will discuss the place in therapy, mechanism of action, pharmacokinetic, pharmacodynamic, and other pharmacologic considerations encountered when prescribing commonly used antibiotics in patients with chronic kidney disease or ESKD.

A Case of Ertapenem Neurotoxicity Resulting in Vocal Tremor and Altered Mentation in a Dialysis Dependent Liver Transplant Patient

Carbapenem agents are advanced derivatives of cephalosporins that are active against bacteria that produce extended spectrum beta lactamases (ESBL). These antibiotics are resistant to enzymatic cleavage, and have good central nervous system penetration. Given this fact, it is not surprising that these drugs have been reported to cause neurological side effects like seizures and encephalopathy. We report a case of a patient on hemodialytic support who had a notable change in mentation and vocal tremor. This was at first attributed to calcineurin toxicity, but after the finding of a normal tacrolimus level, ertapenem neurotoxicity was suspected. After discontinuation of the offending agent, the patient’s vocal tremor, cognition, and neurological function returned to baseline levels.

Ertapenem-associated neurotoxicity in the spinal cord injury (SCI) population: A case series

Context Ertapenem, a broad spectrum carbapenem antibiotic, is used often in Spinal Cord Injury (SCI) patients due to increased risk factors for multi-drug resistant (MDR) infections in this population. Neurotoxicity, specifically seizures, due to ertapenem is a known adverse effect and has been described previously. Other manifestations such as delirium and visual hallucinations have rarely been reported, and no literature, to the best of our knowledge, specifically describes these effects solely in the SCI population. Findings Four cases of mental status changes and hallucinations in SCI patients attributed to ertapenem therapy are described. Onset of symptoms began between one and six days following initiation of ertapenem and resolved between two to 42 days following discontinuation. Based on the Naranjo probability scale, a probable relationship exists between the adverse events and ertapenem for three out of the four cases. Possible overestimation of renal function and hypoalbuminemia may be contributing factors to the noted adverse reactions. Conclusion/Clinical Relevance The cases described highlight the importance of recognizing ertapenem-associated hallucinations in SCI patients. The population is particularly vulnerable due to risk factors for MDR infections necessitating ertapenem use, possible overestimation of renal function, and a high prevalence of hypoalbuminemia.

Meropenem-vaborbactam for adults with complicated urinary tract and other invasive infections

INTRODUCTION

Complicated urinary tract infections are increasingly caused by multidrug-resistant organisms. Carbapenem-resistant Enterobacteriaceae (CRE) constitute a rising threat among uropathogens with significant morbidity and mortality. Meropenem-vaborbactam is a novel carbapenem and cyclic boronic acid-based beta-lactamase inhibitor combination with potent activity against subtypes of CRE. Areas covered: This article reviews mechanisms of carbapenem resistance, existing treatment options for CRE, and the current evidence to support the use of meropenem-vaborbactam for the treatment of infections caused by subtypes of CRE including complicated urinary tract infections. Expert commentary: Meropenem-vaborbactam is a superior treatment option for infections secondary to Klebsiella pneumoniae carbapenemase (KPC)-producing CRE. It is associated with higher rates of treatment success and lower rates of toxicity than traditional agents and demonstrates a potentially higher barrier to acquired antimicrobial resistance than ceftazidime-avibactam. At present, meropenem-vaborbactam should be regarded as a preferred treatment option for invasive infections secondary to KPC-producing CRE.

Evaluation of Renal Function Estimation Formulas Specific to Dynamic Renal Function for Drug Dosing in Critically Ill Patients

OBJECTIVES

The study compared estimated creatinine clearance (eCrCl) between the Cockcroft-Gault (CG) equation and the Jelliffe, Chiou, and Brater equations designed for estimation in dynamic renal function and resulting antimicrobial dosing concordance of five antimicrobials (cefepime, meropenem, piperacillin/tazobactam, vancomycin, and fluconazole) commonly used in the intensive care unit (ICU).

METHODS

Electronic medical records were used to identify the target patient population. Analysis of variance tests with repeated measures were performed to compare eCrCl. Bowker's tests of symmetry were applied to compare the dosing regimen discordance between CG and candidate equations.

RESULTS

From January 1, 2008 through December 31, 2012, we identified 387 patients with acute kidney injury (AKI), among whom 62% (n = 240) were older adults (65 years and older) and 46% (n = 178) were obese (body mass index ≥30). In the declining phase of renal function, eCrCl means were different between the CG and Brater equations (32.0 vs 26.1 mL/min, P < 0.001). The dosing regimen discordance rates (CG vs candidate equations) in declining renal function varied from 19.3% to 25% and were statistically significant for cefepime and meropenem (P < 0.001) based on Food and Drug Administration recommendations for dose adjustment. In the improving phase, eCrCl means were different (P < 0.001) between CG (43.0 mL/min) and candidate formulas (Brater 47.9, Chiou 31.7, and Jelliffe 55.3 mL/min). The dosing regimen discordance rates (CG vs candidate equations) in the improving phase varied from 8.3% to 39% and were statistically significant for all 5 antimicrobials (P < 0.001).

CONCLUSIONS

Differences in eCrCl between CG and candidate formulas were observed in surgical ICU patients with acute kidney injury. Discordant dosing recommendations may affect antimicrobial regimens in ICU patients with dynamic renal function.

In Vitro Activity of β-Lactams in Combination with β-Lactamase Inhibitors against Mycobacterium tuberculosis Clinical Isolates

OBJECTIVES

Evaluating the activity of nineteen β-lactams in combination with different β-lactamase inhibitors to determine the most potent combination against Mycobacterium tuberculosis (MTB) in vitro.

METHODS

Drug activity was examined by drug susceptibility test with 122 clinical isolates from China. Mutations of blaC and drug targets ldtMt1 , ldtMt2 , dacB2, and crfA were analyzed by nucleotide sequencing.

RESULTS

Tebipenem (TBM) in combination with clavulanate (CLA) exhibited the highest anti-TB activity. The MIC of β-lactam antibiotics was reduced most evidently in the presence of CLA, compared to avibactam (AVI) and sulbactam (SUB). Eight polymorphism sites were identified in blaC, which were not associated with β-lactams resistance. Interestingly, one strain carrying G514A mutation in blaC was highly susceptible to β-lactams regardless of the presence of inhibitors. The transpeptidase encoding genes, ldtMt1 , ldtMt2 , and dacB2, harboured three mutations, two mutations, and one mutation, respectively, but no correlation was found between these mutations and drug resistance.

CONCLUSION

The activity of β-lactams against MTB and different synergetic effect of β-lactamase inhibitors were indicated. TBM/CLA exhibited the most activity and has a great prospect in developing novel anti-TB regimen; however, further clinical research is warranted. Moreover, the resistance to the β-lactam antibiotics might not be conferred by single target mutation in MTB and requires further studies.

Neurological Adverse Effects Attributable to β-Lactam Antibiotics: A Literature Review

β-lactam antibiotics are commonly prescribed antibiotic drugs. To describe the clinical characteristics, risk markers and outcomes of β-lactam antibiotic-induced neurological adverse effects, we performed a general literature review to provide updated clinical data about the most used β-lactam antibiotics. For selected drugs in each class available in France (ticarcillin, piperacillin, temocillin, ceftazidime, cefepime, cefpirome, ceftaroline, ceftobiprole, ceftolozane, ertapenem and aztreonam), a systematic literature review was performed up to April 2016 via an electronic search on PubMed. Articles that reported original data, written in French, Spanish, Portuguese or English, with available individual data for patients with neurological symptoms (such as seizure, disturbed vigilance, confusional state, myoclonia, localising signs, and/or hallucinations) after the introduction of a β-lactam antibiotic were included. The neurological adverse effects of piperacillin and ertapenem are often described as seizures and hallucinations (>50 and 25% of cases, respectively). Antibiotic treatment is often adapted to renal function (>70%), and underlying brain abnormalities are seen in one in four to one in three cases. By contrast, the neurological adverse drug reactions of ceftazidime and cefepime often include abnormal movements but few hallucinations and seizures. These reactions are associated with renal insufficiency (>80%) and doses are rarely adapted to renal function. Otherwise, it appears that monobactams do not have serious neurological adverse drug reactions and that valproic acid and carbapenem combinations should be avoided. The onset of disturbed vigilance, myoclonus, and/or seizure in a patient taking β-lactam antibiotics, especially if associated with renal insufficiency or underlying brain abnormalities, should lead physicians to suspect adverse drug reactions and to consider changes in antibacterial therapy.

Antiepileptic drugs in critically ill patients

BACKGROUND

The incidence of seizures in intensive care units ranges from 3.3% to 34%. It is therefore often necessary to initiate or continue anticonvulsant drugs in this setting. When a new anticonvulsant is initiated, drug factors, such as onset of action and side effects, and patient factors, such as age, renal, and hepatic function, should be taken into account. It is important to note that the altered physiology of critically ill patients as well as pharmacological and nonpharmacological interventions such as renal replacement therapy, extracorporeal membrane oxygenation, and target temperature management may lead to therapeutic failure or toxicity. This may be even more challenging with the availability of newer antiepileptics where the evidence for their use in critically ill patients is limited.

MAIN BODY

This article reviews the pharmacokinetics and pharmacodynamics of antiepileptics as well as application of these principles when dosing antiepileptics and monitoring serum levels in critically ill patients. The selection of the most appropriate anticonvulsant to treat seizure and status epileptics as well as the prophylactic use of these agents in this setting are also discussed. Drug-drug interactions and the effect of nonpharmacological interventions such as renal replacement therapy, plasma exchange, and extracorporeal membrane oxygenation on anticonvulsant removal are also included.

CONCLUSION

Optimal management of antiepileptic drugs in the intensive care unit is challenging given altered physiology, polypharmacy, and nonpharmacological interventions, and requires a multidisciplinary approach where appropriate and timely assessment, diagnosis, treatment, and monitoring plans are in place.

The Effect of Different Carbapenem Antibiotics (Ertapenem, Imipenem/Cilastatin, and Meropenem) on Serum Valproic Acid Concentrations

BACKGROUND

Carbapenem antibiotics (CBPMs) may significantly reduce the serum concentration of valproic acid (VPA), but the extent of this effect among various CBPMs is unknown. This study compared the extent and onset of the interactions among ertapenem, imipenem/cilastatin, and meropenem.

METHODS

A 5-year retrospective study was performed. Hospitalized patients over 18 years old who received VPA and a CBPM concurrently were enrolled via the pharmacy computer system. Patients who lacked VPA serum concentration measurements before or during CBPMs' use, had concurrent medication(s) that might interfere with VPA metabolism, or had a history of liver cirrhosis were excluded. Total VPA serum concentrations before and during CBPMs' use and after its discontinuation were recorded, and differences among various CBPMs were analyzed.

RESULTS

Fifty-two patients were included in this analysis. Irrespective of the route of administration, VPA serum concentrations were subtherapeutic in 90% of the subjects during CBPMs' use. There was a significant decrease (P < 0.001) in VPA serum concentrations during the use of CBPMs: 72% ± 17%, 42% ± 22%, and 67% ± 19% in the ertapenem (N = 9), imipenem/cilastatin (N = 17), and meropenem (N = 26) groups, respectively. The effect of ertapenem and meropenem on VPA was significantly more expressed than that of imipenem/cilastatin (P < 0.005). The onset of this drug interaction occurred within 24 hours of CBPMs' administration, and VPA serum concentrations returned to 90% of baseline within 7 days of CBPMs' discontinuation along with a 20% increase in VPA dose. Increasing VPA dose during the use of ertapenem or meropenem did not result in elevating VPA serum concentrations to therapeutic levels during the combined therapy period.

CONCLUSIONS

CBPMs reduced VPA serum concentration within 24 hours of administration by approximately 60%. Ertapenem and meropenem had a greater effect on VPA serum concentration than imipenem/cilastatin. Because of the dramatic reduction of VPA serum concentration during CBPMs' use, concomitant use of VPA and CBPMs should be avoided.

Risk factors associated with the development of seizures among adult patients treated with ertapenem: A matched case-control study

Objective

The purpose of this study is to compare the characteristics of those ertapenem-treated adult patients with and without development of seizures, and identify the associated factors for the development of seizures.

Methods

This retrospective study was conducted at Chia-Yi Christian Hospital from January 2012 to December 2014. Patients developing seizures during their ertapenem treatment course were identified as case patients. Those without seizures who had received ertapenem for at least five days were considered as the pool of control patients. For each case patient, four matched patients from the control pool were randomly selected as the final control group, based on age, gender, and the date of ertapenem prescription.

Results

A total of 1706 ertapenem-treated patients were identified, 33 (1.9%) individuals developed seizures with the enrollment of 132 matched control patients. Among these 33 patients, the average age was 79.3 ± 7.5 years, and 20 (60.6%) were male. The mean Charlson co-morbidity score was 4.5 ± 2.4, and the first episode of seizure happened 3.3 ± 2.6 days after receiving ertapenem. In multivariate logistic regression analysis, the independent predictors associated with the development of ertapenem-associated seizures were old stroke (OR, 14.36; 95% CI, 4.38–47.02; p < 0.0001), undergoing brain images within one year prior to the admission (OR, 5.73; 95% CI, 1.78–18.43; p = 0.0034), low hemoglobin level (OR, 3.88; 95% CI, 1.28–12.75; p = 0.0165) and low platelet count (OR, 4,94; 95% CI, 1.56–15.68; p = 0.0067) at presentations, and protective factors against the development of seizures were heart failure (OR, 0.04; 95% CI, 0.00–0.63; p = 0.0222), concomitant use of steroids (OR, 0.19; 95% CI, 0.05–0.77; p = 0.0201), or antiplatelet agents (OR, 0.12; 95% CI, 0.02–0.63, p = 0.0123) with ertapenem.

Conclusions

The development of ertapenem-associated seizures may occur more frequently and much earlier due to its widespread use in treating drug-resistant pathogens, especially when these pathogens emerged worldwide.Our study would help physician to estimate the risk of developing seizure among patients receiving ertapenem.

Ertapenem-Induced Encephalopathy in a Patient With Normal Renal Function

Drug-induced neurotoxicity is a rare adverse reaction associated with ertapenem. Encephalopathy is a type of neurotoxicity that is defined as a diffuse disease of the brain that alters brain function or structure. We report a patient with normal renal function who developed ertapenem-induced encephalopathy manifesting as altered mental status, hallucinations, and dystonic symptoms. The patient’s symptoms improved dramatically following ertapenem discontinuation, consistent with case reports describing ertapenem neurotoxicity in renal dysfunction. Since clinical evidence strongly suggested ertapenem causality, we utilized the Naranjo Scale to estimate the probability of an adverse drug reaction to ertapenem. Our patient received a Naranjo Scale score of 7, suggesting a probable adverse drug reaction, with a reasonable temporal sequence to support our conclusion.

Neurologic Complications of Commonly Used Drugs in the Hospital Setting

This chapter reviews the neurologic complications of medications administered in the hospital setting, by class, introducing both common and less common side effects. Detail is devoted to the interaction between pain, analgesia, sedation, and their residual consequences. Antimicrobials are given in nearly every hospital setting, and we review their capacity to produce neurologic sequelae with special devotion to cefepime and the antiviral treatment of human immunodeficiency virus. The management of hemorrhagic stroke has become more complex with the introduction of novel oral anticoagulants, and we provide an update on what is known about reversal of the new oral anticoagulants. Both central and peripheral nervous system complications of immunosuppressants and chemotherapies are reviewed. Because diagnosis is generally based on clinical acumen, alone, neurotoxic syndromes resulting from psychotropic medications may be easily overlooked until severe dysautonomia develops. We include a practical approach to the diagnosis of serotonin syndrome and neuroleptic malignant syndrome.

Safety of high-dose doripenem in adult patients with cystic fibrosis

BACKGROUND

High doses of β-lactam antibiotics have been advocated for acute pulmonary exacerbations caused by Pseudomonas aeruginosa in patients with cystic fibrosis (CF) secondary to high minimum inhibitory concentrations (MIC) of the infecting organisms. Some β-lactam antibiotics have increased elimination in CF patients. This case series examines the safety of high-dose doripenem (HDD), 2 g intravenously every 8 hours, which is 4 times the labeled dose, in CF patients.

METHODS

This was a retrospective, single site, chart review of all CF patients given HDD during a 3-year period. Adverse events were prospectively defined using labeled definitions within the package insert and the medical literature. A standard case report form was used to collect demographic details, antibiotic lengths of therapy and adverse events.

RESULTS

A total of 17 patients (9 males), with a median age of 24 years, contributed 43 unique visits and 382 HDD exposure days. Mean duration of inpatient doripenem use was 8.9 days. Concurrent antibiotics were common, with a median number of additional antibiotics per admission of three. The median number of adverse effects documented was two. The most common adverse event was anemia, which was identified in 41 of 43 visits, but was present on admission in 31 instances. One patient developed leukopenia for 1 day, but returned to normal without dose adjustment. There were three instances of Clostridium difficile infection. One patient was documented to have an allergic reaction that led to discontinuation, but was ultimately rechallenged without adverse effect. Other common adverse events were gastrointestinal in origin. No other possible adverse effects led to discontinuation of the drug.

CONCLUSIONS

In adult patients with CF, HDD in combination with other antibiotics did not lead to adverse effects necessitating discontinuation. HDD should be considered in this selected patient population, particularly when high MIC organisms are identified.

Personalised beta-lactam therapy: basic principles and practical approach

Bacterial infections are potentially life-threatening diseases requiring effective antibiotic treatment right from the outset to achieve a favourable prognosis. Therapeutic success depends on the susceptibility of the bacterial pathogen, determined by the minimum inhibitory concentration (MIC), and the concentration of the antibiotic at the focus of infection, which is influenced by drug metabolism and pharmacokinetic (PK) factors. Beta-lactams are time-dependent antibiotics. Bacterial killing correlates with the duration of the drug concentration above the MIC of the pathogen. Critical illness is associated with major PK changes. This may lead to unexpected drug concentrations and unpredictable dose requirements differing significantly from standard dosages. Emerging dosing strategies are therefore based on PK/pharmacodynamic (PD) principles. Therapeutic drug monitoring (TDM) is increasingly playing a key role in antibiotic treatment optimisation in general and in beta-lactam therapy, in particular, notably in severely ill patients. Furthermore, evidence of the superiority of continuous beta-lactam infusions over shorter administration regimens is growing. Target drug concentrations have to be defined, considering MIC values especially in pathogens with limited susceptibility. For reliable TDM results, correct pre-analytical sample handling is indispensable. Personalised, TDM-guided therapy currently offers the most promising approach to assuring that beta-lactam treatment is effective, especially in critically ill patients.

Status Epilepticus and Delirium Associated with Ertapenem in a Very Elderly Patient with Chronic Kidney Disease and Silent Ischaemic Cerebrovascular Disease

An 85-year-old female with chronic kidney disease and newly acquired seizures on oral phenytoin received intravenous ertapenem 500 mg once daily for a urinary tract infection and bacteraemia involving extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. After three ertapenem doses, she developed seizures which self-aborted. Corrected phenytoin level was sub-therapeutic initially, but became therapeutic following a phenytoin dose increase. On Day 14 of ertapenem, the patient suffered another episode of seizure. Ertapenem was stopped. On Day 15, she developed status epilepticus lasting 2 days, requiring intravenous lorazepam, sodium valproate and phenytoin. The last episode of seizure occurred 3 days after discontinuation of ertapenem, with a dramatic recovery of her Glasgow Coma Scale and resolution of delirium. At the time of writing, she has remained seizure free for over 2 years. A retrospective audit of the emergency department notes revealed that she had a course of ertapenem in another institution prior, which also led to two seizure episodes—once 8 days after starting ertapenem, another 3 days after stopping ertapenem. Despite using a renal-adjusted ertapenem dose, each dip in her creatinine clearance level was associated with seizures, preceded by delirium each time. Naranjo assessment score was 6, suggesting a probable relationship between the seizures and ertapenem.

Seizures as adverse events of antibiotic drugs: A systematic review

OBJECTIVE

Antibiotic drugs are commonly associated with seizures. Tailoring antibiotics to the individual risk for seizures is challenged as avoidance of certain antibiotic classes may no longer be possible due to the emergence of resistant bacteria. We performed a systematic review regarding the current evidence for seizures associated with all antibiotic classes, their underlying mechanisms, and predisposing factors.

METHODS

The medical search engine PubMed was systematically screened to identify articles in English published between 1960 and 2013. All study designs were considered and evidence was assessed.

RESULTS

We included 143 articles involving 25,712 patients and 25 different antibiotics. Evidence for antibiotic-related symptomatic seizures is low to very low, mainly deriving from studies regarding β-lactams, especially unsubstituted penicillins and fourth-generation cephalosporins, as well as carbapenems, mainly imipenem, all administered in high doses or in patients with renal dysfunction, brain lesions, or known epilepsy. Evidence regarding symptomatic seizures from fluoroquinolones only relies on case reports and case series with most reports for ciprofloxacin in patients with renal dysfunction, mental disorders, prior seizures, or coadministered theophylline.

CONCLUSIONS

Evidence for an association between antibiotic drugs and symptomatic seizures is low to very low (evidence Class III-IV). Despite this, numerous reports point to an increased risk for symptomatic seizures especially of unsubstituted penicillins, fourth-generation cephalosporins, imipenem, and ciprofloxacin in combination with renal dysfunction, brain lesions, and epilepsy. During administration of such antibiotics in patients with particular predispositions, close monitoring of serum levels is advocated. As most seizures associated with cephalosporins are nonconvulsive, continuous EEG should be considered in patients with altered levels of consciousness.

Oral and intramuscular treatment options for early postpartum endometritis in low-resource settings: a systematic review

OBJECTIVE

To suggest options for oral and intramuscular antibiotic treatment of early postpartum endometritis in low-resource community settings where intravenous antibiotics are unavailable.

DATA SOURCES

Studies were identified through MEDLINE from inception through December 2014. Search terms included [("anti-bacterial agents [MeSH]" or "anti-infective agents [MeSH]") and ("endometritis [MeSH]" or "puerperal infection [MeSH]")]. A second search using the terms [("endometritis or endomyometritis or puerperal infection) and ("antibiotics or antimicrobials or anti-bacterial agents or anti-infective agents)"] was also used. Additionally, all references from selected articles were reviewed, a hand-search of a subject matter expert library was conducted, and a search of ClinicalTrials.gov was performed.

METHODS OF STUDY SELECTION

We conducted a systematic review of the literature in two phases. Phase I provides a summary of clinical cure data from prospective studies of oral and intramuscular antimicrobial regimens as well as summarizes evidence from trials of intravenous antimicrobials. Phase II is a quantitative analysis of pathogens from intrauterine postpartum endometritis samples. Based on these results, and with consideration of existing recommendations for antibiotic use during breastfeeding, we suggest oral and intramuscular antimicrobial options for the treatment of early postpartum endometritis after vaginal delivery in low-resource settings.

TABULATION, INTEGRATION, AND RESULTS

Reports involving oral or intramuscular antimicrobial treatment of postpartum endometritis are rare and of generally poor quality. Antimicrobial trials of postpartum endometritis treatment and intrauterine microbiology studies suggest five antimicrobial regimens may be effective: oral clindamycin plus intramuscular gentamicin, oral amoxicillin-clavulanate, intramuscular cefotetan, intramuscular meropenem or imipenem-cilastatin, and oral amoxicillin in combination with oral metronidazole.

CONCLUSION

This review provides suggestions for oral, intramuscular, and combined antimicrobial regimens that may warrant additional study. Experimental trials should consider clinical effectiveness, safety and side effects profiles, and feasibility of community-based treatment.

Pharmacological interaction between valproic acid and carbapenem: what about levels in pediatrics?

Valproic acid (VPA) is the most commonly used antiepileptic drug in pediatric patients, but its major drawback is its multiple pharmacological interactions.

OBJECTIVE

To study children who had been simultaneously treated with carbapenems and valproic acid, considering drug levels, pharmacological interactions and clinical follow-up.

MATERIAL AND METHODS

Retrospective study of children who simultaneously received treatment with VPA and carbapenems between January 2003 and December 2011. Demographic variables, indication of treatment, dose, VPA plasma levels, interactions, clinical manifestations and medical management were analyzed.

RESULTS

28 children with concomitant treatment with both drugs were included in the study. 64.3% were males. 78.6% of the interactions were observed in the Intensive Care Unit. 60.7% of children had been previously treated VPA and its major indication were generalized seizures. Basal plasma levels of VPA were recorded in 53% and at 24 h after admittance in 60%. "40% of basal VPA levels were below therapeutic range prior to the administration of carbapenem. After the introduction of carbapenem 88% of level determinations were below therapeutic range". 54.5% of the patients that were chronically receiving VPA and had good control of epilepsy before admission had seizures during the coadministration. One patient that was on VPA before admission but with bad control of epilepsy worsened, and one patient that acutely received VPA did not achieve seizure freedom. In these cases it was necessary to either increase VPA dose or change to a different antiepileptic drug.

CONCLUSIONS

Little is known about the mechanism of pharmacologic interactions between carbapenems and VPA, but it leads to a reduction in plasma levels that may cause a loss of seizure control, so simultaneous use of both drugs should be avoided when possible. If not, VPA levels should be monitored.