Linezolid and the risk of lactic acidosis: Data mining and analysis of the FDA Adverse Event Reporting System

Linezolid and tedizolid adverse effects: a review on serotonin syndrome, myelosuppression, neuropathies, and lactic acidosis

Oxazolidinone antibiotics-linezolid and tedizolid-are often used to treat multidrug-resistant infections. They are highly bioavailable and ideal for transition to enteral therapy when appropriate. However, multiple associated adverse effects are potentially treatment-limiting. The objective of this review is to discuss relevant adverse effects of linezolid and tedizolid, including serotonin syndrome, myelosuppression, neuropathies, and lactic acidosis, and their commonality in real-world experience in the last decade. Mitigation strategies, including the role of therapeutic drug monitoring, are also discussed.

Linezolid-Induced Lactic Acidosis Presenting As Acute Cholecystitis: A Case Report and Systematic Review

Linezolid has gained increased use for the treatment of infections caused by multidrug-resistant Gram-positive bacteria in recent years. It can cause rare but potentially life-threatening lactic acidosis. Here, we presented a case report of linezolid-induced lactic acidosis (LILA), along with a systematic review of current literature. The patient was a 55-year-old male who presented with the symptoms of acute cholecystitis. He had been treated for sepsis due to acute cholecystitis with broad-spectrum antibiotics and intravenous fluids as per protocol. Still, his lactate level was getting elevated. After excluding other causes of lactic acidosis, LILA was diagnosed, and linezolid was discontinued. His lactic acid level, as well as his physical condition, improved after that. Studies related to LILA were searched in Medline via PubMed. After screening titles, abstracts, and full texts, data were extracted, tabulated, and presented in this article. The risk of bias was also assessed. We found 78 relevant articles in the primary search, and 26 articles, including 496 patients, were included in the study. From 23 studies of 129 patients, 28 patients (21.7%) died in the setting of LILA. The peak lactate level in which the patient developed LILA was 38.1 mmol/L after four weeks of therapy. The most common health conditions associated with LILA were end-stage renal failure (ESRD), diabetes mellitus (DM), hypertension, chronic obstructive pulmonary disease (COPD), etc. Eighteen studies with a total of 30 patients discontinued it after the development of LILA. Twenty-four patients (80%) out of 30 survived after the discontinuation. We recommend including LILA in the differential diagnoses when treating patients with lactic acidosis since LILA is associated with a relatively elevated mortality rate.

Neonatal Cardiac and Respiratory Arrest During Linezolid Therapy: A Case Report

Lactic acidosis is one of the severe adverse reactions of linezolid. Its clinical manifestations are non-specific, primarily including abdominal discomfort, nausea, vomiting, diarrhea, weakness, lethargy, rapid breathing, and tachycardia, with no reports of cardiac and respiratory arrest. In this case report, we present a 13-day-old male infant with omphalitis caused by methicillin-resistant Staphylococcus aureus (MRSA) infection, who was treated with linezolid. He had lactic acidosis before treatment, which was not severe and was likely related to the infection. After linezolid therapy, he experienced cardiac and respiratory arrest, and re-measurement showed an increase in lactate levels. After resuscitation, linezolid withdrawal, and symptomatic treatment, lactate levels decreased. However, due to hypoxic-ischemic encephalopathy and uncorrectable ventricular arrhythmia caused by post-cardiopulmonary resuscitation myocardial damage, the infant died. A comprehensive autopsy and genetic testing were performed after death, and no congenital diseases or inherited metabolic diseases were found. Given that this case was a sudden infant death without typical symptoms of lactic acidosis and linezolid is often mistakenly considered safer than vancomycin in the treatment of special populations, this paper analyzes and discusses this to draw attention to clinical treatment. More research is needed in the future to fully demonstrate its causal relationship and mechanism of action.

Pharmacovigilance Strategies to Address Resistance to Antibiotics and Inappropriate Use-A Narrative Review

The spread of antimicrobial resistance (AMR) is a global challenge. Close and continuous surveillance for quick detection of AMR can be difficult, especially in remote places. This narrative review focuses on the contributions of pharmacovigilance (PV) as an auxiliary tool for identifying and monitoring the ineffectiveness, resistance, and inappropriate use of antibiotics (ABs). The terms "drug ineffective", "therapeutic failure", "drug resistance", "pathogen resistance", and "multidrug resistance" were found in PV databases and dictionaries, denoting ineffectiveness. These terms cover a range of problems that should be better investigated because they are useful in warning about possible causes of AMR. "Medication errors", especially those related to dose and indication, and "Off-label use" are highlighted in the literature, suggesting inappropriate use of ABs. Hence, the included studies show that the terms of interest related to AMR and use are not only present but frequent in PV surveillance programs. This review illustrates the feasibility of using PV as a complementary tool for antimicrobial stewardship activities, especially in scenarios where other resources are scarce.

Comparison of the incidence of nausea and vomiting between linezolid and vancomycin using claims database: a retrospective cohort study

BACKGROUND

Nausea and vomiting during linezolid therapy have been reported as part of safety analyses in clinical trials. We have previously examined the incidence of vomiting during linezolid therapy (18.1%). A previous study conducted at a single hospital showed low external validity. It is necessary to verify whether these results can be reproduced using generalizable data sources.

AIM

To evaluate the incidence of nausea and vomiting during linezolid therapy compared with vancomycin using a Japanese claims database.

METHOD

Patients administered linezolid or vancomycin were selected from the database between January 2005 and June 2017. The primary endpoint was the comparison of nausea and vomiting between the linezolid and vancomycin groups. We conducted propensity score matching (PSM) to adjust for patient characteristics. To assess risk factors for nausea and vomiting, logistic regression was conducted as the secondary endpoint. We defined nausea and vomiting as the first prescription of antiemetics during linezolid or vancomycin therapy as a surrogate endpoint.

RESULTS

In total, 1215 patients were enrolled. After PSM, the number of patients in the linezolid and vancomycin groups was 241. Nausea and vomiting were observed in 11.2% and 5.0% of patients in the linezolid and vancomycin groups, respectively (p < 0.05). Linezolid administration was extracted as a risk factor for nausea and vomiting (odds ratio, 2.09; 95% confidence interval, 1.02-4.30).

CONCLUSION

This study clarified the relationship between linezolid and nausea and vomiting using a Japanese claims database. Further studies are required to elucidate the unknown mechanisms of linezolid-induced nausea and vomiting.

Adverse drug events associated with linezolid administration: a real-world pharmacovigilance study from 2004 to 2023 using the FAERS database

Introduction: Linezolid is an oxazolidinone antibiotic that is active against drug-resistant Gram-positive bacteria and multidrug-resistant Mycobacterium tuberculosis. Real-world studies on the safety of linezolid in large populations are lacking. This study aimed to determine the adverse events associated with linezolid in real-world settings by analyzing data from the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS). Methods: We retrospectively extracted reports on adverse drug events (ADEs) from the FAERS database from the first quarter of 2004 to that of 2023. By using disproportionality analysis including reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), along with the multi-item gamma Poisson shrinker (MGPS), we evaluated whether there was a significant association between linezolid and ADE. The time to onset of ADE was further analyzed in the general population and within each age, weight, reporting population, and weight subgroups. Results: A total of 11,176 reports of linezolid as the "primary suspected" drug and 263 significant adverse events of linezolid were identified, including some common adverse events such as thrombocytopenia (n = 1,139, ROR 21.98), anaemia (n = 704, ROR 7.39), and unexpected signals that were not listed on the drug label such as rhabdomyolysis (n = 90, ROR 4.33), and electrocardiogram QT prolonged (n = 73, ROR 4.07). Linezolid-induced adverse reactions involved 27 System Organ Class (SOC). Gender differences existed in ADE signals related to linezolid. The median onset time of all ADEs was 6 days, and most ADEs (n = 3,778) occurred within the first month of linezolid use but some may continue to occur even after a year of treatment (n = 46). Conclusion: This study reports the time to onset of adverse effects in detail at the levels of SOC and specific preferred term (PT). The results of our study provide valuable insights for optimizing the use of linezolid and reducing potential side effects, expected to facilitate the safe use of linezolid in clinical settings.

Linezolid dose adjustment according to therapeutic drug monitoring helps reach the goal concentration in severe patients, and the oldest seniors benefit more

BACKGROUND

The elderly with severe infection increased dramatically in intensive care unit (ICU). Proper antimicrobial therapy help improve the prognosis. Linezolid, as an antimicrobial drug, is commonly utilized to treat patients infected with methicillin-resistant S. aureus and vancomycin-resistant enterococci. Clinical evidence suggests elderly patients prone to linezolid overexposure. Here, we describe the results of three years' linezolid adjustment experiences according to therapeutic drug monitoring (TDM), especially in the oldest old.

METHODS

Linezolid therapeutic drug monitoring data were collected between January 2020 and November 2022 from patients who were admitted to ICU and treated with linezolid. All the patients started with a dosage of 600 mg, twice daily. The first TMD was carried out ten minutes before the seventh administration. The dosage adjustment was determined by the doctor according to the first TMD and patients' condition, and the repeated TDM was conducted as required. The dosage adjustment in different age group was recorded. Laboratory data were compared between the old and the oldest old. The high mortality risk of the oldest old was also explored.

RESULTS

Data of 556 linezolid TDM from 330 patients were collected. Among which, 31.6%, 54.8%, and 75% of patients had supra-therapeutic linezolid trough concentrations at the first TDM assessment in different age group, leading to the dosage adjustment rate of 31.0%, 40.3%, 68.8% respectively. The linezolid dosage adjustments according to TDM help to reach therapeutic concentration. The oldest old was in high risk of linezolid overexposure with lowercreatinine clearance. The norepinephrine maximum dosage but not linezolid Cmin was associated with 28-day mortality in the oldest old.

CONCLUSIONS

Elderly patients with linezolid conventional 600 mg twice-daily dose might be at a high risk of overexposure, especially in the oldest old. The linezolid dosage adjustments according to TDM help reach the therapeutic concentration. The high mortality of the oldest old was not related with initial linezolid overexposure.

Hematological toxicities associated with linezolid therapy in adults: key findings and clinical considerations

INTRODUCTION

Linezolid can cause serious adverse effects including thrombocytopenia and anemia. Here, we focus specifically on linezolid-related hematological toxicity in adult patients requiring prolonged drug treatment.

AREAS COVERED

We review the available evidence on the likelihood of hematological toxicity in adult patients treated with linezolid, with a focus on the main risk factors and strategies to prevent this adverse event. A MEDLINE PubMed search for articles published from January 2000 to May 2022 was completed matching the terms linezolid, hematology, hematological toxicity, anemia, and thrombocytopenia. Moreover, additional studies were identified from the reference lists of retrieved articles.

EXPERT OPINION

Thrombocytopenia is the major concern with administration of linezolid for Gram-positive infections, whereas anemia is more common in patients with tuberculosis. The important clinical risk factors for the development of linezolid-related thrombocytopenia are aging, renal dysfunction, low baseline platelet count, duration of treatment, and linezolid plasma trough concentrations >8 mg/L. Patients receiving linezolid for extended periods of time or patient populations with increased risk of altered drug pharmacokinetics would benefit from therapeutic drug monitoring or from the availability of toxico-dynamic predictive models to optimize linezolid dosing.

Asparaginase-related diabetic ketoacidosis: Analysis of the FDA Adverse Event Reporting System (FAERS) data and literature review

WHAT IS KNOWN AND OBJECTIVE

Diabetic ketoacidosis (DKA) may occur during asparaginase use. However, limited by the study population, the association between asparaginase and DKA has not been elucidated. The purpose of this study was to determine the potential association between asparaginase and DKA and analyse related clinical characteristics and possible risk factor.

METHODS

Disproportionality analysis with the reporting odd ratio (ROR) was used to detect the adverse reaction signals of asparaginase-associated DKA in Food and Drug Administration Adverse Event Reporting System (FAERS). A literature review was conducted to further analyse clinical characteristics, possible risk factor and something noteworthy in asparaginase-associated DKA.

RESULTS AND DISCUSSION

A total of 12 reports of DKA associated with l-asparaginase (l-asp) and 6 reports associated with pegaspargase (PEG-asp) were extracted in FAERS, more than 50% of the cases were classified as serious adverse events. DKA was a positive signal of l-asp (ROR = 2.397, 95% CI 1.360-4.226), while not closely related to the use of PEG-asp (ROR = 1.602, 95% CI 0.719-3.570). Searched in PubMed, Embase and Web of Science, a total of eight patients were collected. The patients were mainly adolescent patients, aged between 11 and 25 years old with a median age of 16 years. Drug dosage form distribution is unbalanced, 7 patients received l-asp and only 1 received PEG-asp.

WHAT IS NEW AND CONCLUSIONS

The ROR of KDA caused by l-asp was statistically significant, but there was not a statistical association for DKA caused by PEG-asp. Asparaginase dosage form may affect the occurrence of DKA, but further research is needed.

Lactic acidosis associated with standard dose linezolid in a kidney recipient with impaired renal function

Severe lactic acidosis, a mitochondrial toxicity caused by the recommended standard dosage of linezolid (LZD), may occur in patients with impaired renal function. We describe an adult male who underwent kidney transplantation with stably impaired renal function, severe dyspnea, and abdominal discomfort. He received a standard oral dose of LZD (600 mg twice daily) and azithromycin for three weeks with a reduced immunosuppressant dose due to pulmonary non-tuberculosis mycobacterial infection. He was alert and afebrile, with a blood pressure of 140/60 mmHg. Pertinent laboratory data showed: pH 7.12, PaCO2 13.6 mmHg; HCO3- 4.3 mmol/L and serum lactate 18.4 mmol/L. His trough serum LZD concentration reached toxic levels (21.4 μg/mL). With hemodialysis, his clinical symptoms improved, with a decline in serum LZD (9.8μg/mL) and lactate (3.2 mmol/L). Chronic standard dose LZD in patients with impaired renal function can lead to life-threatening lactic acidosis, especially in coexisting conditions that reduce LZD metabolism.

Therapeutic Drug Monitoring of Antibiotics in the Elderly: A Narrative Review

PURPOSE

Antibiotic dosing adaptation in elderly patients is frequently complicated by age-related changes affecting the processes of drug absorption, distribution, metabolism, and/or elimination. These events eventually result in treatment failure and/or development of drug-related toxicity. Therapeutic drug monitoring (TDM) can prevent suboptimal antibiotic exposure in adult patients regardless of age. However, little data are available concerning the specific role of TDM in the elderly.

METHODS

This review is based on a PubMed search of the literature published in the English language. The search involved TDM studies of antibiotics in the elderly performed between 1990 and 2021. Additional studies were identified from the reference lists of the retrieved articles. Studies dealing with population pharmacokinetic modeling were not considered.

RESULTS

Only a few studies, mainly retrospective and with observational design, have specifically dealt with appropriate antibiotic dosing in the elderly based on TDM. Nevertheless, some clinical situations in which the selection of optimal antibiotic dosing in the elderly was successfully guided by TDM were identified.

CONCLUSIONS

Elderly patients are at an increased risk of bacterial infections and inadequate drug dosing compared to younger patients. Therefore, the availability of TDM services can improve the appropriateness of antibiotic prescriptions in this population.

Investigation of the risk factors of vomiting during linezolid therapy: a retrospective observational study

PURPOSE

Some clinical studies have reported the occurrence of nausea and vomiting with linezolid (LZD) administration. However, no studies have evaluated nausea and vomiting as primary endpoints. In a previous study, we noted a possible relationship between LZD and vomiting, but risk factors were not identified. Therefore, the aim of the present study was to identify them.

METHODS

Patients who received LZD 600 mg twice daily at Hokkaido University Hospital from September 2008 to April 2019 were enrolled in this retrospective observational study. Patient characteristics, concomitant medications, laboratory data, and the occurrence of vomiting were obtained from electronic medical records. Logistic regression analysis was performed to identify risk factors for vomiting, including age, sex, body weight, concomitant medications, and surgeries.

RESULTS

A total of 496 patients were included in this study, of which 90 experienced vomiting. By multivariate logistic regression analysis, female sex (adjusted odds ratio [aOR], 2.69; 95% confidence interval [CI], 1.62-4.47), ≥ 10 days of LZD administration (aOR, 2.57; CI, 1.46-4.50), and hyponatraemia (aOR, 2.96; CI, 1.72-5.10) were identified as independent risk factors for vomiting; administration of serotonergic agents (aOR, 0.23; CI, 0.07-0.82) was negatively associated.

CONCLUSIONS

This study is the first to successfully identify risk factors for LZD-induced vomiting. Careful monitoring of patients with these risk factors may lead to safer and sustainable LZD administration.

Supra-therapeutic Linezolid Trough Concentrations in Elderly Patients: A Call for Action?

BACKGROUND AND OBJECTIVE

According to the drug label, linezolid dosage adjustments are not needed in geriatric patients. Nevertheless, clinical evidence suggests that elderly patients may benefit from the use of reduced linezolid doses to limit drug overexposure. Here, we aimed to describe the results of the last 5 years of therapeutic drug monitoring of linezolid in our institution with a special focus on elderly patients.

METHODS

Linezolid therapeutic drug monitoring requests collected between January 2016 and June 2020 were considered. Linezolid trough concentrations were considered both as a continuous variable and as a categorical variable, clustering data according to the therapeutic range proposed by available literature (< 2, 2-8, and > 8 mg/L, respectively). Patients' age and sex were considered as categorical variables. Comparisons of linezolid trough concentrations between groups of patients stratified according to age were performed using an analysis of variance; comparisons in the frequency distributions were performed using the chi-squared test.

RESULTS

From 2016 to 2020, we collected 3250 linezolid TDM requests. A highly significant, progressive increment in the linezolid trough concentrations was observed moving from patients aged < 50 years (5.8 ± 5.6 mg/L) to those aged > 90 years (16.6 ± 10.0 mg/L), with an overall increment of 30% per decade of age. Nearly 30%, 50%, and 65% of patients aged < 65 years, 65-80 years, and > 80 years, respectively, had supra-therapeutic linezolid trough concentrations at the first therapeutic drug monitoring assessment. This trend did not change significantly moving from 2016 to 2020.

CONCLUSIONS

Elderly patients given linezolid at the conventional 600-mg twice-daily dose might be at a high risk of being overexposed to treatment, eventually increasing their risk to experience drug-related hematological toxicity. Reduced linezolid dosing schemes should be potentially considered in elderly patients at a low risk of treatment failure, ideally guided by therapeutic drug monitoring.