Retrospective analysis of the risk factors for linezolid-induced thrombocytopenia in adult Japanese patients

Linezolid-Associated Thrombocytopenia: Assessment of Risk Factors in Patients without Hemato-Oncologic Diseases

Background: Linezolid is used for Gram-positive bacterial infections. Thrombocytopenia is one of its main adverse effects resulting from myelosuppression. Several studies have assessed risk factors that may increase the risk of this adverse effect. However, most studies included patients with hemato-oncologic diseases, which may confound such assessments. This study aimed to investigate risk factors for linezolid-associated thrombocytopenia in patients without hemato-oncologic diseases. Methods: This was a multicenter retrospective case-control study of adult patients treated with linezolid twice daily for ≥3 days. Patients with hemato-oncologic diseases, active dengue fever, active COVID-19, baseline platelet count <100 × 103/mm3, concurrent therapy with trimethoprim/sulfamethoxazole or valproic acid, and a recent platelet transfusion within 7 days were excluded. Thrombocytopenia was defined as a drop in platelet count below 100 × 103/mm3. Results: Out of 158 evaluated patients, 33 developed thrombocytopenia, indicating an incidence rate of 20.9%. Of all the risk factors assessed, creatinine clearance of <60 mL/min and bacteremia/infective endocarditis were significantly associated with linezolid-associated thrombocytopenia (adjusted odds ratios, 3.25 and 5.95; 95% CI 1.12-9.45 and 1.23-28.66; p = 0.031 and 0.026, respectively). End of therapy platelet counts were significantly lower in the cases than in the controls (79 vs. 243 × 103/mm3; p < 0.001). Similarly, the percentage of platelet count change was significantly different (-55.1% vs. -10.2%; p < 0.001). Conclusions: In our study, the incidence rate of linezolid-associated thrombocytopenia was 20.9%, and we found that patients with renal impairment and bacteremia may need close monitoring of platelet counts. Prospective studies are warranted to evaluate the potential need for renal dose adjustment.

Linezolid-Induced Thrombocytopenia in Patients with Renal Impairment: A Case Series, Review and Dose Advice

BACKGROUND AND OBJECTIVE

Oral linezolid is often used as alternative therapy for intravenous vancomycin. According to the current guidelines, no dose adjustment has to be made in case of renal impairment. Nevertheless, in our hospital we have seen several patients with renal impairment who developed linezolid-induced thrombocytopenia when linezolid was taken in the standard dose. In this case series and review we want to emphasize the necessity of reviewing the Dutch and international guidelines.

METHODS

We describe five cases with renal impairment that developed linezolid-induced thrombocytopenia in our hospital. A PubMed literature review was conducted to identify other cases and find the optimal dosing regimen for these patients.

RESULTS

Our cases join a long list of cases and available literature about linezolid-induced thrombocytopenia in patients with renal impairment. Less linezolid-induced thrombocytopenia was found, both in our cases and in the literature, after dose reduction of 50%. High linezolid trough concentrations were associated with a higher risk of linezolid-induced thrombocytopenia. Besides renal impairment, other risk factors for developing linezolid-induced thrombocytopenia were also identified, such as low body weight, high daily dose/kg, higher age, longer duration of therapy, low baseline count, malignity, low-dose aspirin and interacting co-medication.

CONCLUSION

Re-evaluation of the current dose advice is necessary. We advocate for a standard dose reduction to 50% after 2 days of standard dosing for all patients with an estimated glomerular filtration of <60 mL/min/1.73 m2. Besides this, therapeutic drug monitoring and thrombocytes monitoring may be executed weekly when patients have renal impairment or other risk factors for developing linezolid-induced thrombocytopenia.

Development and validation of a risk prediction model for linezolid-induced thrombocytopenia in elderly patients

OBJECTIVES

Linezolid is the first oxazolidinone antimicrobial agent developed for treating multi-drug-resistant gram-positive bacterial infections. The study aimed to investigate the risk factors of linezolid (LI)-induced thrombocytopenia (LI-TP) and to develop and validate a risk prediction model to identify elderly patients at high risk of developing LI-TP during linezolid therapy.

METHODS

A retrospective cohort study was performed at Zhongshan Hospital, FuDan University, China. The study involved elderly Chinese patients aged ≥65 years administered with linezolid (600 mg) twice a day between January 2015 and April 2021. We collected the patients' clinical characteristics and demographic data from electronic medical records, and compared the differences between LI-TP patients and those who had not developed thrombocytopenia (NO-TP) after linezolid treatment. The risk prediction model was developed based on the regression coefficient generated from logistic regression model.

RESULTS

A total of 343 inpatients were enrolled from January 2015 to August 2020 and were used as the training set. Among them, 67 (19.5%) developed LI-TP. Multivariate logistic regression analysis revealed that baseline platelet counts <150×109·L-1 (odds ratio (OR)=3.576; p<0.001), age ≥75 years (OR=2.258; p=0.009), estimated glomerular filtration rate (eGFR <60 mL·(min·1.73 m2)-1 (OR=2.553; p=0.002), duration of linezolid therapy ≥10 d (OR=3.218; p<0.001), intensive care unit (ICU) admittance (OR=2.682; p=0.004), concomitant piperacillin-tazobactam (OR=3.863; p=0.006) were independent risk factors for LI-TP in elderly patients. The LI-TP risk prediction model was established using a scoring method based on the regression coefficient and exhibited a good discriminative power, with an area under the curve (AUC) of 0.795 (95% confidence interval (CI) 0.740 to 0.851) and 0.849 (95% CI 0.760 to 0.939) in the training set (n=343) and validation set (n=90) respectively.

CONCLUSIONS

These findings indicate that duration of linezolid therapy, age, eGFR, ICU admittance, baseline platelet counts, concomitant piperacillin-tazobactam were significantly associated with LI-TP in elderly patients. A risk prediction model based on these risk factors showed a good discriminative performance and may be useful for clinicians to identify patients at high risk of developing LI-TP.

Prediction of risk factors for linezolid-induced thrombocytopenia based on neural network model

Background: Based on real-world medical data, the artificial neural network model was used to predict the risk factors of linezolid-induced thrombocytopenia to provide a reference for better clinical use of this drug and achieve the timely prevention of adverse reactions. Methods: The artificial neural network algorithm was used to construct the prediction model of the risk factors of linezolid-induced thrombocytopenia and further evaluate the effectiveness of the artificial neural network model compared with the traditional Logistic regression model. Results: A total of 1,837 patients receiving linezolid treatment in a hospital in Xi 'an, Shaanxi Province from 1 January 2011 to 1 January 2021 were recruited. According to the exclusion criteria, 1,273 cases that did not meet the requirements of the study were excluded. A total of 564 valid cases were included in the study, with 89 (15.78%) having thrombocytopenia. The prediction accuracy of the artificial neural network model was 96.32%, and the AUROC was 0.944, which was significantly higher than that of the Logistic regression model, which was 86.14%, and the AUROC was 0.796. In the artificial neural network model, urea, platelet baseline value and serum albumin were among the top three important risk factors. Conclusion: The predictive performance of the artificial neural network model is better than that of the traditional Logistic regression model, and it can well predict the risk factors of linezolid-induced thrombocytopenia.

Towards a better detection of patients at-risk of linezolid toxicity in clinical practice: a prospective study in three Belgian hospital centers

Introduction: Linezolid is a last-resort antibiotic for infections caused by multidrug-resistant microorganisms. It is widely used for off-label indications and for longer than recommended treatment durations, exposing patients at higher risk of adverse drug reactions (ADRs), notably thrombocytopenia. This study aimed to investigate ADR incidence and risk factors, identify thrombocytopenia-related trough levels based on treatment duration, and evaluate the performance of predictive scores for ADR development. Methods: Adult in- and outpatients undergoing linezolid therapy were enrolled in three hospitals and ADRs and linezolid trough levels prospectively monitored over time. A population pharmacokinetic (pop-PK model) was used to estimate trough levels for blood samples collected at varying times. Results: A multivariate analysis based on 63 treatments identified treatment duration ≥10 days and trough levels >8 mg/L as independent risk factors of developing thrombocytopenia, with high trough values correlated with impaired renal function. Five patients treated for >28 days did not develop thrombocytopenia but maintained trough values in the target range (<8 mg/L). The Buzelé predictive score, which combines an age-adjusted Charlson comorbidity index with treatment duration, demonstrated 77% specificity and 67% sensitivity to predict the risk of ADR. Conclusion: Our work supports the necessity of establishing guidelines for dose adjustment in patients with renal insufficiency and the systematic use of TDM in patients at-risk in order to keep trough values ≤8 mg/L. The Buzelé predictive score (if ≥7) may help to detect these at-risk patients, and pop-PK models can estimate trough levels based on plasma samples collected at varying times, reducing the logistical burden of TDM in clinical practice.

Evaluation of the impact of rifampicin on the plasma concentration of linezolid in tuberculosis co-infected patients

Linezolid combined with rifampicin has shown excellent clinical outcomes against infection by multi-resistant Gram-positive bacteria. However, several studies have indicated that rifampicin reduces the plasma concentration of linezolid in patients with severe infection. Linezolid has been recommended for the treatment of patients with multidrug-resistant or extensively drug-resistant tuberculosis. However, studies on the interaction between linezolid and rifampicin in patients suffering from tuberculosis with infection are lacking. We evaluated the interaction between linezolid and rifampicin based on therapeutic drug monitoring (TDM). A retrospective analysis was undertaken for patients with tuberculosis and infection who were treated with linezolid and undergoing TDM. Patients were divided into the linezolid group and linezolid + rifampicin group. Data on demographic characteristics, disease, duration of linezolid therapy, and the plasma concentration of linezolid were used for statistical analyses. Eighty-eight patients with tuberculosis and infection were assessed. Values for the peak (Cmax) and trough (Cmin) concentrations of linezolid in plasma were available for 42 and 46 cases, respectively. Patients in the linezolid group had a significantly higher Cmax [15.76 (8.07-26.06) vs. 13.18 (7.48-23.64) mg/L, p = 0.048] and Cmin [8.38 (3.06-16.53) vs. 4.27 (0.45-10.47), p = 0.005] than those in the linezolid + rifampicin group. The plasma concentration of linezolid increased obviously in two patients after rifampicin discontinuation. However, the total efficiency and prevalence of hematologic adverse reactions were not significantly different in the linezolid group and linezolid + rifampin group. The plasma concentration of linezolid decreased upon combination with rifampicin, suggesting that TDM may aid avoidance of subtherapeutic levels of linezolid upon co-treatment with rifampicin.

Risk factors for thrombocytopenia in patients receiving linezolid therapy: a systematic review and meta-analysis

PURPOSE

The incidence of linezolid-induced thrombocytopenia (LIT) has been reported to vary widely across studies. We performed a meta-analysis to identify the risk factors for thrombocytopenia among patients who received linezolid treatment.

METHODS

The PubMed, Embase and Cochrane Library databases were searched from inception to November 2022 to identify eligible studies. Data on the potential predictors of incidence in LIT were pooled using a random effects model. Sensitivity analyses were performed to determine the robustness of the results when significant heterogeneity was observed.

RESULTS

Forty observational studies involving 6454 patients treated with linezolid were included in the analysis. LIT was estimated to occur in 37% of patients. The following important factors were associated with the incidence of LIT: advanced age, body mass index, concurrent renal impairment or liver disease, abnormal laboratory parameters (including white blood cell count, serum creatinine, baseline platelet count, albumin, creatinine clearance rate, and estimated glomerular filtration rate), treatment duration and renal replacement therapy.

CONCLUSIONS

A variety of risk factors related to the occurrence of LIT were revealed in our analysis. Early identification of these factors could help patients improve clinical outcomes.

Effect of Platelet Parameters on Linezolid-Related Thrombocytopenia in Hospitalized Patients

Background

Linezolid-induced thrombocytopenia incidence varies considerably. Linezolid-related thrombocytopenia in patients has received few studies which have investigated risk factors including platelet parameters except for platelet counts. The study aims to analyze the effect of platelet parameters, including mean platelet volume and platelet large cell ratio, on linezolid-related thrombocytopenia in patients.

Methods

The effect of platelet parameters on linezolid-related thrombocytopenia was identified by univariate and multivariate logistic regressions. A Kaplan-Meier survival analysis was carried out to compare the survival of patients who developed linezolid-related thrombocytopenia with patients who did not.

Results

Thrombocytopenia occurred at a rate of 41.5% (66/159) after linezolid therapy in hospitalized patients. Platelet parameters, including the difference in mean platelet volume (MPV/fL=0.08 (-1.2-0.9)vs-0.5 (-1.5-0.3), (OR, 0.459; P = 0.001), the difference in platelet large cell ratio (PLCR/fL=0.9 (-5.1-6.2)vs-3.8 (-8.6-2.4), (OR, 1.156; P = 0.001), baseline platelet counts (OR, 0.995; P = 0.006) and duration of linezolid therapy≥10d (OR, 1.346; P = 0.007), were significantly associated with linezolid-related thrombocytopenia in hospitalized patients. In addition, other risk factors which also are associated with linezolid-related thrombocytopenia include baseline red blood cells, co-medication with parecoxib and co-medication with caspofungin. Accumulated in-hospital mortality of patients with thrombocytopenia was significantly higher than that of patients without thrombocytopenia during linezolid treatment (19.7% vs 8.6%, P = 0.003).

Conclusion

The difference in mean platelet volume, the difference in large platelet ratio, baseline platelet counts and duration of linezolid therapy≥10d significantly affected the development of linezolid-related thrombocytopenia in hospitalized patients.

Effect of linezolid on platelet count in critically ill patients with thrombocytopenia

INTRODUCTION

Linezolid (LZD) is one of the antibiotics used to treat methicillin-resistant Staphylococcus aureus. In Japan, the dose of LZD is not generally adjusted by renal function or therapeutic drug monitoring and is readily available for critically ill patients. The adverse effects of LZD include pancytopenia, especially thrombocytopenia. We investigated the effect of LZD on platelet counts in critically ill patients with thrombocytopenia during admission to the intensive care unit (ICU).

METHODS

Fifty-five critically ill patients with existing thrombocytopenia (platelet count < 100 ×103 /μL) who received LZD for five days or more during the period from January 2011 to October 2018 were included. Changes in platelet count and frequency of platelet concentrate (PC) transfusion were evaluated retrospectively.

RESULTS

Mean (± standard error) platelet count prior to initiation of LZD was 47 ± 4 ×103 /uL, which increased significantly to 86 ± 13 ×103 /uL on day 15 (p<0.01). Median [interquartile range] duration of LZD therapy was 9 [8-12] days. Thirty-two patients (58.2%) required PC transfusion in the 15-day study period. The daily rate of PC transfusion decreased from 30.2% on days 1-5 to 18.2% on days 11-15. Similar tendencies were observed in patients with non-hematological and hematological disease.

CONCLUSION

Thrombocytopenia in critically ill patients in the ICU did not worsen after initiation of LZD therapy, and may be considered for the treatment of MRSA in this setting.

Use of Japanese big data from electronic medical records to investigate risk factors and identify their high-risk combinations for linezolid-induced thrombocytopenia

PURPOSE

Thrombocytopenia is a major event associated with linezolid (LZD) therapy. Factors affecting LZD-induced thrombocytopenia (LIT) have been reported in previous studies. However, several issues pertaining to LIT have not yet been clarified. In the present study, we used Japanese big data to investigate associated factors and their high-risk combinations that influence LIT.

METHODS

Patients administered LZD between May 2006 and October 2020 were included in this study. LIT was defined as either a 30% or more reduction from the baseline platelets or platelet values of < 100,000/µL. We evaluated factors affecting LIT and combinations of factors that alter LIT risk according to a decision tree (DT) analysis, a typical machine learning method.

RESULTS

We successfully enrolled 1399 patients and LIT occurred in 44.7% of the patients (n = 626). We classified the laboratory data on renal function, LZD duration, age, and body weight (BW) into smaller categories. The results of multivariate analysis showed that prolonged LZD therapy, BW < 45 kg, estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m², and dialysis were risk factors for LIT. The DT analysis revealed that the highest risk was a combination of LZD duration ≥ 14 days and eGFR < 30 mL/min/1.73 m².

CONCLUSIONS

The present study extracted four risk factors and identified high-risk combinations for LIT. Patients with these risk factors should be closely monitored.

Safety of linezolid in patients with decreased renal function and trough monitoring: a systematic review and meta-analysis

BACKGROUND

Linezolid causes hematological toxicity, mostly thrombocytopenia, which leads to treatment discontinuation and failure. Recent studies revealed that during linezolid therapy, the incidence of treatment-related hematological toxicity is significantly higher in patients with decreased renal function (DRF) than in those with normal renal function. Linezolid monitoring is necessary due to the high frequency of hematological toxicity in patients with DRF and the relationship between blood concentration and safety. We performed a systematic review and meta-analysis to evaluate the safety correlation between DRF and trough monitoring.

METHODS

Articles published before June 24, 2022, on MEDLINE, Web of Sciences, Cochrane Register of Controlled Trials, and ClinicalTrials.gov were systematically analyzed. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using the Mantel-Haenszel method and the variable effects model.

RESULTS

The incidence of hematological toxicity was significantly higher in patients with DRF than in those without DRF (OR = 2.37; p < 0.001). Subgroup analysis, performed according to hematotoxicity classification, including thrombocytopenia, anemia, and pancytopenia, revealed a significantly higher incidence of thrombocytopenia (OR = 2.45; p < 0.001) and anemia (OR = 2.31; p = 0.006) in patients with DRF than in those without; pancytopenia (OR = 1.41; p = 0.80) incidences were not significantly higher. Based on a systematic review, linezolid trough concentrations > 6-7 μg/mL may be associated with an increased incidence of thrombocytopenia. However, no confidential threshold values for the development of thrombocytopenia were found in the area under the concentration curve values for children or adults.

CONCLUSION

We observed a high frequency of hematological toxicity during linezolid therapy in patients with DRF. To ensure safety, linezolid trough concentrations should be ≤6-7 μg/mL.

Successful treatment of disseminated nocardiosis diagnosed by metagenomic next-generation sequencing: A case report and review of literature

BACKGROUND

Nocardia paucivorans is an infrequently found bacterium with the potential to cause severe infection, with a predilection for the central nervous system, both in immunocompromised and immunocompetent individuals. Rapid etiological diagnosis of nocardiosis can facilitate timely and rational antimicrobial treatment. Metagenomic next-generation sequencing (mNGS) can improve the rate and reduce the turnaround time for the detection of Nocardia.

CASE SUMMARY

A 49-year-old man was admitted to hospital with cough and hemoptysis. Imaging revealed pulmonary consolidation as well as multiple brain lesions. Nocardia asiatica and Nocardia beijingensis were rapidly detected by mNGS of bronchoalveolar lavage fluid (BALF) while bacterial culture of BALF and pathological biopsy of lung tissue were negative. In early stages, he was treated with trimethoprim-sulfamethoxazole (TMP-SMZ) and linezolid by individual dose adjustment based on serum concentrations and the adverse effects of thrombocytopenia and leukopenia. The treatment was then replaced by TMP-SMZ and ceftriaxone or minocycline. He was treated with 8 mo of parenteral and/or oral antibiotics, and obvious clinical improvement was achieved with resolution of pulmonary and brain lesions on repeat imaging.

CONCLUSION

mNGS provided fast and precise pathogen detection of Nocardia. In disseminated nocardiosis, linezolid is an important alternative that can give a better outcome with the monitoring of linezolid serum concentrations and platelet count.

Linezolid-Induced Pancytopenia in Patients Using Dapagliflozin: A Case Series

Background

Linezolid is classed as oxazolidinone antibiotics which can be used to treat severe infections caused by vancomycin-resistant Enterococcus faecium, hospital-acquired pneumonia caused by Staphylococcus aureus, complicated skin, and uncomplicated skin structure infections (SSSIs) caused by methicillin-susceptible S. aureus or Streptococcus pyogenes, and community-acquired pneumonia caused by Streptococcus pneumoniae. However, many studies have suggested it can also cause thrombocytopenia and pancytopenia.

Patients and Methods

We report on three patients with linezolid-pancytopenia. Patients in cases 1 and 2 were diagnosed with heart failure with preserved ejection fraction (HFpEF) and were both administered with dapagliflozin, one of the sodium-dependent glucose transporters 2 inhibitors (SHLT-2i).

Results

Two patients were diagnosed with type 2 diabetes, pneumonia, and hyponatremia. Severe myelosuppression occurred in both patients, with a severe decrease in leukocytes and platelets and a moderate decrease in hemoglobin, who eventually passed away despite the discontinuation of linezolid and adopting appropriate treatment measures. The patient in case 3 was diagnosed with pneumonia, type 2 diabetes, and sequelae of cerebral thrombosis. After twelve days of treatment, the patient developed moderate thrombocytopenia and anemia. She recovered without any additional treatment after the discontinuation of linezolid.

Conclusion

In this case series, two patients with irreversible myelosuppression were treated with both linezolid and SGLT-2i, and one diabetic patient with single linezolid use presented with reversible pancytopenia, suggesting that SGLT-2i may exacerbate myelosuppression of linezolid. Linezolid should be used with caution in infectious patients with a history of SGLT-2i. We will conduct relevant animal experiments to clarify the interaction between the two drugs.

Relationship Between Linezolid Exposure and the Typical Clinical Laboratory Safety and Bacterial Clearance in Chinese Pediatric Patients

Objectives: There have been limited studies concerning the safety and efficacy of linezolid (LZD) in children. This study aimed to evaluate the association between LZD exposure and clinical safety and efficacy in Chinese pediatric patients.

Methods: This retrospective cross-sectional study included patients ≤18 years of age who received ≥3 days of LZD treatment between 31 January 2015, and 31 December 2020. Demographic characteristics, medication information, laboratory test information, and bacterial culture results were collected from the Hospital Information System (HIS). Exposure was defined as AUC₂₄ and calculated by the non-linear mixed-effects modeling program (NONMEM), version 7.2, based on two validated population pharmacokinetic models. Binary logistic regression analyses were performed to analyze the associations between AUC₂₄ and laboratory adverse events, and receiver operating characteristic curves were used to calculate the cut-off values. Efficacy was evaluated by bacterial clearance.

Results: A total of 413 paediatric patients were included, with an LZD median (interquartile range) dose, duration, clearance and AUC₂₄ of 30.0 (28.1-31.6) mg/kg/day, 8 (4‒15) days,1.31 (1.29-1.32) L/h and 81.1 (60.6-108.7) mg/L·h, respectively. Adverse events associated with TBil, AST, ALT, PLT, hemoglobin, WBC, and neutrophil count increased during and after LZD treatment when compared with before medication (p < 0.05), and the most common adverse events were thrombocytopaenia (71/399, 17.8%) and low hemoglobin (61/401, 15.2%) during the LZD treatment. Patients with AUC₂₄ higher than 120.69 mg/L h might be associated with low hemoglobin 1–7 days after the end of the LZD treatment, and those with an AUC₂₄ higher than 92.88 mg/L∙h might be associated with thrombocytopaenia 8–15 days after the end of the LZD treatment. A total of 136 patients underwent bacterial culture both before and after LZD treatment, and the infection was cleared in 92.6% (126/136) of the patients, of whom 69.8% (88/126) had AUC₂₄/MIC values greater than 80.

Conclusion: Hematological indicators should be carefully monitored during LZD treatment, especially thrombocytopaenia and low hemoglobin, and a continuous period of monitoring after LZD withdrawal is also necessary. Since the AUC₂₄ cut-off values for laboratory adverse events were relatively low, a trade-off is necessary between the level of drug exposure required for treatment and safety, and the exposure target (AUC₂₄/MIC) in pediatric patients should be further studied, especially for patients with complications and concomitant medications.

Linezolid vs Vancomycin in Induced Thrombocytopenia

INTRODUCTION

Linezolid and vancomycin have an important place among therapeutic antimicrobial options for multidrug-resistant gram-positive infections. Thrombocytopenia is an adverse effect reported with both and can lead to treatment interruption. Our objective was to compare the incidence of thrombocytopenia in patients receiving linezolid or vancomycin and to identify risk factors associated with thrombocytopenia.

METHODS

This was a retrospective observational cohort study that involved patients who received linezolid (intravenously or orally) or vancomycin (intravenously) at a tertiary care hospital, between January 2016 and October 2019, for a minimum of 5 days and in whom platelet values were measured during treatment. Data on platelet count were collected during therapy in each group to identify the incidence of thrombocytopenia.

RESULTS

A total of 453 patients fulfilled the study criteria; 241 patients received linezolid and 212 patients vancomycin. The main logistic regression analysis revealed that patients in the linezolid group had approximately a four times higher incidence of thrombocytopenia (OR 4.39; 95% CI 2.38-8.08) compared to vancomycin. An increased incidence of thrombocytopenia was associated with advanced age, baseline platelet count and vasopressor use.

CONCLUSION

Clinicians considering vancomycin or linezolid for a susceptible infection should weigh the higher risk of thrombocytopenia that may be observed with linezolid vs. vancomycin in their decision.

Renal replacement therapy and concurrent fluconazole therapy increase linezolid-related thrombocytopenia among adult patients

Linezolid has been reported to be associated with thrombocytopenia. However, limited information is available on susceptibility to thrombocytopenia after linezolid usage. We aimed to investigate the risk factors for linezolid-associated thrombocytopenia (LAT). We conducted a retrospective cohort study of patients aged ≥ 18 years who received linezolid for ≥ 5 d during hospitalization in 2019. Information was extracted from electronic medical records. Thrombocytopenia was defined as a platelet count of < 100 × 10⁹/L or a reduction from baseline ≥ 25%. Binary logistic regression and survival analyses were used to evaluate the risk factors for LAT. A total of 98 patients were enrolled. Thrombocytopenia occurred in 53.1% patients, with a median of 9 d after initiation of linezolid. There was no significant difference in the mortality or proportion of platelet transfusions between patients with and without thrombocytopenia. A higher risk of LAT was found in patients who received renal replacement therapy (RRT) (OR 4.8 [1.4–16.4]), or concurrent fluconazole (OR 3.5 [1.2–9.8]). Patients who received RRT (8 vs. 15 d) or concurrent fluconazole (11 vs. 15 d) had a shorter median time to develop thrombocytopenia. Those who simultaneously received RRT and fluconazole had the shortest median of time (6.5 d) and the highest risk of developing thrombocytopenia (87.5%).

Linezolid induced thrombocytopenia in critically ill patients: Risk factors and development of a machine learning-based prediction model

INTRODUCTION

Linezolid is an antimicrobial with broad activity against Gram-positive bacteria. Thrombocytopenia is one of its most common side effects often leading to severe complications. The aim of this study is to identify factors related with development of this condition in critically ill patients and to develop and evaluate a predictive machine learning-based model considering easy-to-obtain clinical variables.

METHODS

Data was obtained from the Medical Information Mart for Intensive Care III. Patients who received linezolid for over three days were considered, excluding those under 18 years and/or lacking laboratory data. Thrombocytopenia was considered as a platelet decrease of at least 50% from baseline.

RESULTS

Three hundred and twenty patients met inclusion criteria of which 63 developed thrombocytopenia and presented significant greater duration of treatment, aspartate-aminotransferase, bilirubin and international normalized ratio; and lower renal clearance and platelet count at baseline. Thrombocytopenia development was associated with a worse outcome (30 days mortality [OR: 2.77; CI95%: 1.87-5.89; P < .001], 60 days mortality [OR: 3.56; CI95%: 2.18-7.26; P < .001]). Thrombocytopenia was also correlated with higher length of hospital stays (35.56 [20.40-52.99] vs 22.69 [10.05-38.61]; P < .001). Median time until this anomaly was of 23 days (CI95%:19.0-NE). Two multivariate models were performed. Accuracy, sensitivity, specificity and AUROC obtained in the best of them were of 0.75, 0.78, 0.62 and 0.80, respectively.

CONCLUSION

Linezolid associated thrombocytopenia entails greater mortality rates and hospital stays. Although the proposed predictive model has to be subsequently validated in a real clinical setting, its application could identify patients at risk and establish screening and surveillance strategies.

Dosage Strategy of Linezolid According to the Trough Concentration Target and Renal Function in Chinese Critically Ill Patients

Background: Linezolid is associated with myelosuppression, which may cause failure in optimally treating bacterial infections. The study aimed to define the pharmacokinetic/toxicodynamic (PK/TD) threshold for critically ill patients and to identify a dosing strategy for critically ill patients with renal insufficiency.

Methods: The population pharmacokinetic (PK) model was developed using the NONMEM program. Logistic regression modeling was conducted to determine the toxicodynamic (TD) threshold of linezolid-induced myelosuppression. The dosing regimen was optimized based on the Monte Carlo simulation of the final model.

Results: PK analysis included 127 linezolid concentrations from 83 critically ill patients at a range of 0.25–21.61 mg/L. Creatinine clearance (CrCL) was identified as the only covariate of linezolid clearance that significantly explained interindividual variability. Thirty-four (40.97%) of the 83 patients developed linezolid-associated myelosuppression. Logistic regression analysis showed that the trough concentration (Cmin) was a significant predictor of myelosuppression in critically patients, and the threshold for Cmin in predicting myelosuppression with 50% probability was 7.8 mg/L. The Kaplan–Meier plot revealed that the overall median time from the initiation of therapy to the development of myelosuppression was 12 days. Monte Carlo simulation indicated an empirical dose reduction to 600 mg every 24 h was optimal to balance the safety and efficacy in critically ill patients with CrCL of 30–60 ml/min, 450 mg every 24 h was the alternative for patients with CrCL &lt;30 ml/min, and 600 mg every 12 h was recommended for patients with CrCL ≥60 ml/min.

Conclusion: Renal function plays a significant role in linezolid PKs for critically ill patients. A dose of 600 mg every 24 h was recommended for patients with CrCL &lt;60 ml/min to minimize linezolid-induced myelosuppression.

Continuous Versus Intermittent Linezolid Infusion for Critically Ill Patients with Hospital-Acquired and Ventilator-Associated Pneumonia: Efficacy and Safety Challenges

High variability of linezolid blood concentrations with partial subtherapeutic levels was observed in critically ill patients who received a standard intravenous dose of linezolid, contributing to drug resistance and toxicity. Continuous infusions of linezolid have been suggested as an alternative and provide good serum and alveolar levels without fluctuations in trough concentration. This study aimed to assess the effectiveness and safety of continuous linezolid infusion versus the standard regimen in critically ill patients. A prospective randomized controlled study was conducted on 179 patients with nosocomial pneumonia. Patients were randomized into two groups. The first group received IV linezolid 600 mg twice daily, while the second group received 600 mg IV as a loading dose, followed by a continuous infusion of 1200 mg/day (50 mg/h) for at least 8−10 days. The continuous infusion group showed a higher clinical cure rate than the intermittent infusion group (p = 0.046). Furthermore, efficacy was proven by greater improvement of P/F ratio (p = 0.030) on day 7 of treatment, a lower incidence of developing sepsis after beginning treatment (p = 0.009), and a shorter time to reach clinical cure (p < 0.001). Hematological parameters were also assessed during the treatment to evaluate the safety between the two groups. The incidence of thrombocytopenia was significantly lower in the continuous infusion group than in the intermittent infusion group. In addition, a stepwise logistic regression model revealed that the intermittent infusion of linezolid was significantly associated with thrombocytopenia (OR =4.128; 95% CI = 1.681−10.139; p =0.001). The current study is the first to assess the clinical aspects of continuous infusion of linezolid beyond pharmacokinetic studies. Continuous infusion of linezolid outperforms intermittent delivery in safety and improves clinical effectiveness in critically ill patients with Gram-positive nosocomial pneumonia.

Risk factors for linezolid-induced thrombocytopenia in adult inpatients

Background Previous reports about risk factors for linezolid-induced thrombocytopenia have been insufficient, often due to the variability in study design and population, and some factors have not yet been studied. Aim The aims of this study are to determine potential risk factors for linezolid-induced thrombocytopenia, and to analyze the influencing factors of different thrombocytopenia definitions. Method This retrospective study involved patients who were administered intravenous linezolid for ≥ 1 day between January 1, 2015 and January 1, 2021. Their demographic and clinical data were extracted from electronic medical records. Thrombocytopenia was defined as: ①thrombocytopenia with platelet count < 100 × 10⁹/L and a decrease in 25% or more from baseline of the platelet count (criterion 1); ②thrombocytopenia due to a platelet count drop decrease of 25% or more from baseline (criterion 2). Risk factors were determined via binary logistic regression analysis. Results This study included 320 patients. Binary logistic regression analysis indicated that baseline platelet count (p < 0.001), linezolid therapy duration (p = 0.001) and shock (patients require vasoactive medications) (p = 0.019) were independent risk factors for criterion-1thrombocytopenia, while linezolid therapy duration (p < 0.001) and shock (p = 0.015) were independent risk factors for criterion-2 thrombocytopenia. There was also a significant correlation between shock and early-onset thrombocytopenia (p = 0.005 and 0.019 for criterion 1 and criterion 2, respectively). Conclusion Linezolid therapy duration and shock were common causes of different thrombocytopenia definitions; shock was correlated with early-onset thrombocytopenia. Platelet count should be monitored during linezolid therapy especially during long-duration therapy and in shock patients.

Linezolid-induced thrombocytopenia in patients with acute myeloid leukemia: a matched case-control study

PURPOSE

After the wide use of linezolid (LZD), numerous reports of uncontrolled studies have suggested that LZD is associated with high rates of thrombocytopenia. We conducted this matched case-control study to identify the risk factors for LZD-induced thrombocytopenia in patients with acute myeloid leukemia (AML) during the period of myelosuppression.

METHODS

We retrospectively retrieved laboratory and clinical data from the medical records of 180 Chinese with AML. Among them, 60 received ≥ 72 h of therapy with LZD during myelosuppression. The remaining patients who did not receive LZD therapy were matched individually in a ratio of 1:2 according to the basic characteristics of the LZD group.

RESULTS

We found that in the LZD group, age, history of liver or kidney disease, the baseline level of bilirubin, and creatinine clearance rate (CCR) did not affect the recovery time of platelets. Patients who received LZD for more than 7 days during the period of myelosuppression had a significantly longer time of platelet recovery and platelet count increase.

CONCLUSION

The use of LZD > 7 days during the course of myelosuppression and the low level of albumin can prolong the time required for platelet count increase and recovery. Further study is needed to assess the potential adverse effects of LZD in larger AML patient populations.

Hospital Pharmacometrics for Optimal Individual Administration of Antimicrobial Agents for Anti-methicillin-resistant Staphylococcus aureus Infected Patients

Therapeutic drug monitoring and target concentration intervention based on population pharmacokinetic and pharmacodynamic models has been strongly recommended for anti-methicillin-resistant Staphylococcus aureus (MRSA) agents in order to provide appropriate antimicrobial chemotherapy to each individual patient, and pharmacokinetic and pharmacodynamic analyses in hospitalized patients have been actively conducted, as evidenced with vancomycin. Teicoplanin, daptomycin, and linezolid have been the most studied antibiotics, using population pharmacokinetics of patients with MRSA. Infections caused by MRSA have higher severity and fatality rates than other antimicrobial-susceptible infections. Therefore, many medical facilities have been implementing infection control programs based on antimicrobial stewardship to prevent nosocomial infections and drug-resistant strains. Studies detailing pharmacometrics for these antibiotics have been reported to elucidate the pharmacokinetic and pharmacodynamic properties, to determine significant factors influencing variabilities between individuals, and to develop target concentration interventions and dosing regimens for adults, the elderly, patients with renal insufficiency including those on continuous renal replacement therapies, patients with low body weight, obese patients, and pediatric patients. This review presents the details of our recent research on the optimal dosing design of antimicrobial agents for the treatment of MRSA infection based on hospital pharmacometrics. In addition, the prospect of using modeling and simulation has shown major advantages in supporting dosing regimen selection.

Effect of renal function on the risk of thrombocytopenia in patients receiving linezolid therapy: a systematic review and meta-analysis

Aims

The association of renal function and linezolid‐induced thrombocytopaenia (LIT) remains controversial. We performed a meta‐analysis to determine whether impaired renal function is associated with an increased LIT risk.

Methods

We conducted a systematic search of PubMed, EMBASE and the Cochrane Library from inception to February 2021 for eligible studies evaluating the relationship between renal function and LIT. Indicators of renal function included renal impairment (RI), severe RI, haemodialysis status, creatinine clearance rate (Ccr) and estimated glomerular filtration rate (eGFR). Unadjusted and adjusted estimates and 95% confidence intervals (CIs) were calculated separately using a random‐effect model.

Results

A total of 24 studies with 3580 patients were included in the meta‐analysis. RI patients had an increased LIT risk compared to non‐RI patients in both the unadjusted (OR 3.54; 95% CI 2.27, 5.54; I² = 77.7%) and adjusted analyses (OR 2.51; 95% CI 1.82, 3.45; I² = 17.9%). This association persisted in the subset of studies involving only patients receiving a fixed conventional dose (600 mg every 12 h) and other subgroup analyses by ethnicity, sample size and study quality. Moreover, the LIT risk was significantly higher in patients with severe RI and haemodialysis than in patients without severe RI and haemodialysis. The eGFR and Ccr were significantly lower in LIT patients than in non‐LIT patients.

Conclusions

Impaired renal function is associated with an increased risk of LIT. A reduced linezolid dose may be considered in RI patients at a low risk of treatment failure, ideally guided by therapeutic drug monitoring.

Clinical Use and Adverse Drug Reactions of Linezolid: A Retrospective Study in Four Belgian Hospital Centers

In Belgium, linezolid is indicated for pneumonia and skin and soft tissue infections, but is more broadly used, due to its oral bioavailability and activity against multiresistant organisms. This could increase the risk of adverse drug reactions (ADR), notably hematological disorders (anemia, thrombocytopenia), neuropathy, or lactic acidosis. We analyzed linezolid clinical use in relationship with occurrence of ADR in Belgian hospitals and highlighted risk factors associated with the development of thrombocytopenia. A retrospective analysis of electronic medical records and laboratory tests of adult patients treated with linezolid in four Belgian hospitals in 2016 allowed the collection of ADR for 248 linezolid treatments. Only 19.7% of indications were in-label. ADR included 43 thrombocytopenia, 17 anemia, 4 neuropathies, and 4 increases in lactatemia. In a multi-variate analysis, risk factors of thrombocytopenia were a treatment duration > 10 days, a glomerular filtration rate < 60 mL/min, and a Charlson index ≥ 4. Off-label use of linezolid is frequent in Belgium, and ADR more frequent than reported in the summary of product characteristics, but not statistically associated with any indication. This high prevalence of ADR could be related to a high proportion of patients presenting risk factors in our population, highlighting the importance of detecting them prospectively.

External Evaluation of Population Pharmacokinetics and Pharmacodynamics in Linezolid-Induced Thrombocytopenia: The Transferability of Published Models to Different Hospitalized Patients

BACKGROUND

The objective of this study was to perform an external evaluation of published linezolid population pharmacokinetic and pharmacodynamic models, to evaluate the predictive performance using an independent data set. Another aim was to offer an elegant environment for display and simulation of both the concentration and platelet count after linezolid administration.

METHODS

We performed a systematic literature search in PubMed for all studies evaluating the population pharmacokinetic and pharmacodynamic parameters of linezolid in patients and selected the models to be used for the external validation. The bias of predictions was visually evaluated by plotting prediction errors (PEs) and relative PEs. The precision of prediction was evaluated by calculating the mean absolute error (MAE), root mean squared error (RMSE), and mean relative error (MRE).

RESULTS

Three articles (models A, B, and C) provided linezolid-induced platelet dynamic models using population pharmacokinetic and pharmacodynamic modeling approaches. The PE and relative PE of both linezolid concentrations and platelet counts for models A and C showed similar predictive distributions. With respect to the prediction accuracy of total linezolid concentration, the MAE, RMSE, and MRE of population prediction values for model C was the smallest. The comparison of the MAE, RMSE, and MRE of patient-individual prediction values for the 3 pharmacodynamic models revealed no large differences.

CONCLUSIONS

We confirmed the transferability of published population pharmacokinetic and pharmacodynamic models and showed that they were suitable for extrapolation to other hospitals and/or patients. This study also introduced application software based on model C for the therapeutic drug monitoring of linezolid.

Comparison of linezolid step-down therapy to standard parenteral therapy in methicillin-resistant Staphylococcus aureus bloodstream infections

Data supporting oral step-down therapy in methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) are sparse; linezolid offers potential in this setting. This study aimed to determine the effectiveness and safety of oral step-down linezolid compared with standard parenteral therapy (SPT) in MRSA-BSI. This was a retrospective cohort performed in adults receiving step-down/outpatient linezolid or SPT (vancomycin, daptomycin) for MRSA-BSI from 2011-2019. Primary outcome was 90-day infection-related re-admission (IRR) from clinical worsening/relapse or infection recurrence. 215 patients included (54 linezolid, 161 SPT). Infection sources were skin (34%), bone/joint (15%), endocarditis (13%), other (32%), multiple (6%). Patients receiving SPT more commonly had complicated bacteraemia (72% vs. 41%; P < 0.0001) and metastatic foci (45% vs. 20%; P = 0.001). 90-day IRR occurred in 17% and 26% of linezolid and SPT groups, respectively (P = 0.159). When accounting for disease severity, linezolid use was not independently associated with 90-day IRR (adjOR, 1.0, 95% CI 0.24-4.3; P = 0.986). There were no differences in all-cause 90-day mortality (4% vs. 6%, P = 0.487) or overall incidence of drug-related adverse events (AEs) (17% vs. 16%; P = 0.843) between the groups. More patients in the SPT group developed an AE requiring re-hospitalisation (12% vs. 2%; P = 0.024), most commonly line-related complications. Oral step-down linezolid demonstrated similar clinical and safety outcomes compared with SPT for MRSA-BSI, except linezolid was associated with fewer AEs requiring re-hospitalisation. Additional research is needed exploring step-down linezolid in MRSA-BSI, particularly in patients requiring shorter durations of outpatient therapy.

A systematic review and meta-analysis of myelosuppression in pediatric patients treated with linezolid for Gram-positive bacterial infections

BACKGROUND

The incidence of linezolid-induced myelosuppression in pediatric patients was reported at large difference among prospective studies, with a range of 0-24%. Additionally, there is little study which evaluated the impact of linezolid administration period on myelosuppression in pediatric patients, while it is one of the most frequent reason that linezolid therapy has to be discontinued in adult patients. Here, we performed a systematic review and meta-analysis to reveal the incidence of linezolid-induced thrombocytopenia and anemia, and impact of the administration period of linezolid on myelosuppression based on individual data analysis of pediatric patients.

METHODS

We systematically searched the Scopus, EMBASE, Cochrane Central Register of Controlled Trials, PubMed, and CINAHL until April 2020. We investigated the incidence of linezolid-induced thrombocytopenia and anemia using pooled analysis, and evaluated the impact of linezolid administration period on myelosuppression using meta-analysis.

RESULTS

Thirteen studies with 969 pediatric patients were identified. The pooled incidences of thrombocytopenia and anemia were 9% (95% confidence interval (CI), 3-18%) and 4% (95% CI, 0-12%), respectively. Our meta-analysis showed the extension of linezolid administration period (more than 14 days) resulted in higher incidence of thrombocytopenia (OR 4.86, 95% CI 1.10-21.55) and anemia (OR 4.57, 95% CI 0.13-160.49).

CONCLUSIONS

The incidence of linezolid-induced myelosuppression in pediatric patients was less than 10%. However, our meta-analysis revealed linezolid administration period for more than 14 days was one of risk factors associated with linezolid-induced myelosuppression. Therefore, especially for pediatric patients treated with linezolid for more than 14 days, careful monitoring of myelosuppression is required.

Reversible Myelosuppresion With Prolonged Usage of Linezolid in Treatment of Methicillin-Resistant Staphylococcus aureus

Bone marrow suppression has a wide variety of causes. One of the overlooked causes is linezolid, a drug that is now being extensively used in the management of not only soft tissue infections but also hospital-acquired infections. Methicillin-resistant Staphylococcus aureus (MRSA) is widely being treated with linezolid. It becomes imperative that we comprehensively understand the hematological adverse effect profile of this drug. A reversible myelosuppression is seen with its extended use, though a number of risk factors like renal impairment are usually present. A prompt diagnosis can help us to timely discontinue the drug. We report one such case of an elderly patient with septic arthritis of the knee who developed pancytopenia after 32 days of linezolid therapy. Withdrawal of the drug led to a complete recovery of the blood counts in 21 days.

A retrospective test for a possible relationship between linezolid-induced thrombocytopenia and hyponatraemia

WHAT IS KNOWN AND OBJECTIVE

Thrombocytopenia is one of the typical adverse events caused by linezolid (LZD). Recently, some cases of severe hyponatraemia occurring while receiving LZD have been reported. This study investigated a possible relationship between LZD-induced hyponatraemia and thrombocytopenia and identified the risk factors for hyponatraemia and/or thrombocytopenia.

METHODS

In this retrospective, single-centre, observational cohort study, 63 hospitalized patients aged over 18 years who received intravenous injection of LZD for more than seven consecutive days in Oita University Hospital between April 2015 and March 2018 were analysed.

RESULTS

Thrombocytopenia occurred in 25 (39.7%) patients and hyponatraemia in 11 (17.5%) patients. Seven of 11 patients with hyponatraemia had concurrent thrombocytopenia. Although both serum sodium level and platelet count declined in most patients who developed hyponatraemia, no significant association between thrombocytopenia and hyponatraemia was found. Creatinine clearance level (Ccr) was significantly lower not only in the thrombocytopenia (vs no-thrombocytopenia) but also in the hyponatraemia group (vs no-hyponatraemia group). Univariate and multivariate logistic regression analyses identified different risk factors for thrombocytopenia and/or hyponatraemia (thrombocytopenia: Ccr and administration period; hyponatraemia: serum albumin; thrombocytopenia and hyponatraemia: administration period and serum albumin).

WHAT IS NEW AND CONCLUSION

In conclusion, this study found no significant relationship between LZD-induced thrombocytopenia and hyponatraemia and identified some possible risk factors associated with onset of the two adverse events. These require further validation.

Reversible myelosuppression suspected to be secondary to linezolid in a cat with infected subcutaneous ureteral bypass systems

CASE SUMMARY

A 5-year-old castrated male domestic shorthair cat was presented for a multidrug-resistant Enterococcus faecium urinary tract infection within its bilateral subcutaneous ureteral bypass systems. After considerable consultation, the cat was treated with oral linezolid (10 mg/kg q12h) for two separate 2-week courses over 5 weeks. Over this time period, the cat became progressively neutropenic and thrombocytopenic, but was otherwise clinically stable. Upon cessation of the linezolid, the bicytopenia resolved within 12 days.

RELEVANCE AND NOVEL INFORMATION

The reversible myelosuppression in this case is suspected to be secondary to linezolid administration. While previously reported in people, this effect has not been reported at therapeutic doses in veterinary species. This report demonstrates the potential for adverse drug reaction development in cats treated with prolonged linezolid therapy and highlights the need for extreme caution when utilizing linezolid in patients with renal insufficiency. Linezolid is the only drug currently approved by the Food and Drug Administration to treat vancomycin-resistant enterococci infections in people; however, resistance to this antibiotic appears to be increasing. Multidrug-resistant organisms continue to be a real global public health threat in both human and veterinary medicine. Third-tier antibiotics should only be considered under extreme circumstances and after considerable consultation with a specialist. Please note that the authors of this manuscript followed American Veterinary Medical Association policies on stewardship and International Society for Companion Animal Infectious Diseases guidelines, and do not promote or encourage the use in daily practice.

Linezolid is safe on platelet count for AML patients during myelosuppression after consolidation chemotherapy

BACKGROUND

Patients with acute myeloid leukaemia (AML) often develop severe infections during myelosuppression after chemotherapy. Linezolid is an appropriate choice for these patients when coverage of positive bacteria is needed. An important side effect of linezolid is linezolid-induced thrombocytopenia; so, the safety of linezolid for AML patients in myelosuppression is of concern. No study has focused on platelets in these patients.

METHODS

We reviewed 1356 AML patients who received consolidation chemotherapy in our hospital during January 2009 and June 2019. Among them, 36 patients were treated with linezolid and 41 with vancomycin. We counted the days of platelet count <20*10E9/L, <50*10E9/L, the lowest platelet count, total quantity of platelet transfusion and clinical bleeding events of these patients, to evaluate the safety of linezolid during myelosuppression in AML patients.

RESULTS

The days of platelet count <20*10E9/L in the linezolid group and vancomycin group were 6.2 ± 2.5 days and 6.7 ± 2.9 days, and the days of platelet count <50*10E9/L in the linezolid group and vancomycin group were 10.9 ± 3.6 days and 11.7 ± 4.0 days, respectively; there was no significant difference between the two groups. No life-threatening severe bleeding events occurred in either group.

CONCLUSION

This retrospective clinical study suggests that it is safe to manage AML patients in complete remission during myelosuppression after standard consolidation chemotherapy with idarubicin and cytarabine, with about 7 days of linezolid therapy.

Risk factor analysis for linezolid-associated thrombocytopenia in critically ill patients

Linezolid is an antibiotic used against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. Its primary adverse effect is haematotoxicity. The objective of this study was to analyse the risk factors for onset of thrombocytopenia in critically ill patients treated with linezolid. This was a retrospective, single-centre study of 72 patients. Platelets were measured from D0 to D20 after the start of treatment. The risk factors for thrombocytopenia were identified using a multivariate logistic regression analysis following a Monte Carlo simulation. Following ROC curve analysis, a baseline platelet count lower than 108 × 10⁹/L and a C_min higher than 4 mg/L, with respective odds ratios of 117 (95% CI [97-206]) and 3 (95% CI [1.5-6.2]) in the simulated population, were identified as risk factors. Among the source population patients combining these 2 factors, a significantly higher number developed thrombocytopenia (66.7% vs. 33.3%, p = 0.0042). A baseline platelet count lower than 108 × 10⁹/L and a C_min higher than 4 mg/L are risk factors for the onset of thrombocytopenia in critically ill patients treated with linezolid.

A retrospective cohort study to screen linezolid-induced thrombocytopenia in adult patients hospitalized in the Midwestern Region of Brazil

Background

Thrombocytopenia (TP) is the major event associated with linezolid (LZD) therapy. We investigated the incidence and risk factors for thrombocytopenia in hospitalized adults who received LZD (1200 mg/day) between 2015 and 2017. HIV-positive, death during follow-up and those with a baseline platelet count ≤100 × 10³/mm³ were excluded.

Method

TP was defined as a decrease in platelet count of ≥20% from the baseline level at the initiation of linezolid therapy and a final count of <100 × 10³/mm³. The odds ratios (OR) for thrombocytopenia were obtained using multivariate stepwise logistic regression analysis.

Main results

A total of 66 patients were included (mean age [SD] 62 [18], male gender [%], 37 [56]). LZD-associated TP was identified in 12 patients (18.2%). For TP, the adjusted OR [95% CI] of the platelet count ≤200 × 10³/mm³, serum creatinine and renal impairment at baseline were 5.66 [1.15–27.9], 4.57 [1.26–16.5] and 9.41 [1.09–80.54], respectively. Male gender and dosage per weight per day (DPWD) >20 mg/kg/day were not risk factors.

Conclusion

The results showed that the incidence of linezolid-induced thrombocytopenia was lower in patients with normal renal function and higher in those with platelet counts ≤200 × 10³/mm³ or serum creatinine >1.5 mg/dL at the start of the treatment.

Reappraisal of Linezolid Dosing in Renal Impairment To Improve Safety

Linezolid is administered as a fixed dose to all patients despite evidence of increased exposure and myelosuppression in renal impairment. The objectives of these studies were to assess the risk of thrombocytopenia with standard-dose linezolid in renal impairment and to identify an alternate dosing strategy. In study 1, data from adult patients receiving linezolid for ≥10 days were retrospectively reviewed to determine the frequency of thrombocytopenia in patients with and without renal impairment. Time-to-event analyses were performed using Cox proportional-hazards models. In study 2, population pharmacokinetic modeling was employed to build covariate-structured models using an independent data set of linezolid concentrations obtained during routine therapeutic drug monitoring (TDM). Monte Carlo simulations were performed to identify linezolid dosing regimens that maximized attainment of therapeutic trough concentrations (2 to 8 mg/liter) across various renal-function groups. Toxicity analysis (study 1) included 341 patients, 133 (39.0%) with renal impairment. Thrombocytopenia occurred more frequently among patients with renal impairment (42.9% versus 16.8%; P < 0.001), and renal impairment was independently associated with this toxicity in multivariable analysis (adjusted hazard ratio [aHR], 2.37; 95% confidence interval [CI], 1.52 to 3.68). Pharmacokinetic analyses (study 2) included 1,309 linezolid concentrations from 603 adult patients. Age, body surface area, and estimated glomerular filtration rate (eGFR) were identified as covariates of linezolid clearance. Linezolid dose reductions improved the probability of achieving optimal exposures in simulated patients with eGFR values of <60 ml/min. Thrombocytopenia occurs more frequently in patients with renal impairment receiving standard linezolid doses. Linezolid dose reduction and trough-based TDM are predicted to mitigate this treatment-limiting toxicity.

[Verification of Relationship between Administration of Linezolid and Vomiting]

Linezolid (LZD), an antimicrobial agent against methicillin-resistant Staphylococcus aureus, demonstrates good bone and joint penetration, and is used for prosthetic bone and joint infections. Recently, we observed vomiting in several patients administered LZD. However, there are few reports on the incidence rate of, and risk factors for, LZD-induced nausea and vomiting. In this study, we aimed to verify the relationship between LZD administration and vomiting. Patients administered LZD at the Department of Orthopedic Surgery of Hokkaido University Hospital between November 2008 and December 2017 were enrolled in the study. The primary endpoint was the comparison of the vomiting rate between patients administered LZD (LZD group) and those administered other antibiotics (non-LZD group). For the secondary endpoint, to verify the risk factors of vomiting, a univariate logistic regression analysis was performed. In total, 130 patients were included in this study; 77 patients in the LZD group, and 53 in the non-LZD group. Vomiting occurred in 18 patients in the LZD group and 4 patients in the non-LZD group (23.4% and 7.5%, respectively); this was significantly higher in the LZD group. In the univariate logistic regression analysis, LZD administration, gender (female), age ≥65 years, renal impairment (creatinine clearance <60 mL/min) and concomitant use of rifampicin were extracted as potential risk factors of vomiting. The results of this study reveal a possible relationship between LZD administration and vomiting.

Pharmacokinetics, toxicity and clinical efficacy of linezolid in Japanese pediatric patients

OBJECTIVES

The aims of the present study were (a) to evaluate the pharmacokinetics of linezolid, and (b) to assess the toxicity and clinical efficacy of linezolid in Japanese pediatric patients.

PATIENTS AND METHODS

Routine clinical data including serum linezolid total and unbound concentrations were collected from 15 pediatric patients (0-13 years old). Pharmacokinetics of linezolid was assumed to follow one-compartment with the first-order absorption model. The relationship between risk for thrombocytopenia and linezolid concentrations, and the variations in C-reactive protein (CRP) concentrations and body temperatures were evaluated as clinical efficacy assessment.

RESULTS

Body weight (WT) and maturation of body function were significant covariates for pharmacokinetics of linezolid in pediatric patients. The elimination half-life of linezolid in a pediatric patient with a WT of 9.9 kg and age of 24 months (median of this study) was 3.0 h. Thrombocytopenia was detected in three patients (21.4%), and the minimum concentrations (C_min) in these patients were significantly higher than those in patients without thrombocytopenia (P < 0.05). The CRP concentrations decreased more than 50% in all pediatric patients after the treatment with linezolid, however body temperatures at the end of treatment were higher than 37.5 °C in 6 patients (42.9%).

CONCLUSIONS

Although dose adjustment based on body size was performed for pediatric patients, thrombocytopenia was detected in 21.4% of pediatric patients, and higher C_min was associated with the risk of thrombocytopenia. These results encourage the implementation of individual dose adjustment based on linezolid serum concentrations for safe and appropriate treatment with linezolid.

Real-Life Frequency of New-Onset Thrombocytopenia during Linezolid Treatment

BACKGROUND

Thrombocytopenia is a well-recognized adverse effect of linezolid; however, the frequency of this adverse effect during therapy has been variable across previous studies, and the associated risk factors are unclear.

OBJECTIVES

To identify the real-life frequency of new-onset thrombocytopenia due to linezolid and to determine the associated risk factors.

METHODS

A retrospective observational cohort study was conducted among consecutive inpatients at a tertiary care hospital who received linezolid for a minimum of 5 days between January 2013 and August 2017. Data were extracted from electronic medical records obtained from a hospital database. Thrombocytopenia was defined as platelet count less than 100 × 10⁹/L or a 50% reduction from baseline (i.e., before linezolid initiation). Risk factors were identified by comparing the characteristics of patients who experienced the adverse effect during linezolid therapy with those of patients who did not experience the adverse effect. Continuous data were analyzed with the t test and categorical data with the χ² test.

RESULTS

A total of 102 patients were included (38 women, 64 men; overall mean age 50 years, standard deviation [SD] 21). The mean duration of linezolid therapy was 14 (SD 10) days. Thrombocytopenia occurred in 18 patients (17.6%). Risk factors for the development of thrombocytopenia included mean duration of therapy (22 [SD 18] days versus 12 [SD 7] days; p = 0.023), renal replacement therapy (17% versus 4%; p = 0.032), renal impairment (61% versus 32%; p = 0.021), and concomitant administration of unfractionated heparin (50% versus 21%; p = 0.013).

CONCLUSIONS

The real-life frequency of new-onset of thrombocytopenia in patients receiving linezolid for a minimum of 5 days was 17.6%. Risk factors for linezolid-induced thrombocytopenia included prolonged duration of therapy, renal impairment, and concomitant unfractionated heparin.

Risk factors for linezolid-induced thrombocytopenia in patients without haemato-oncologic diseases

This study aimed to describe the occurrence and to evaluate the predictive factors of thrombocytopenia caused by parenteral linezolid in hospitalised patients without haemato-oncologic diseases. Using electronic medical records, a retrospective safety evaluation was performed among all hospitalised adult patients who received parenteral linezolid therapy between January 2005 and June 2016. Of all identified 264 patients with an average age of 63.4 (SD 15.8) years, thrombocytopenia occurred at a rate of 29.2% after an average of 11.2 (SD 7.4) days of the initiation of linezolid therapy. Significant predictive factors for thrombocytopenia included the duration of linezolid therapy longer than or equal to 7 days (adjusted odds ratios [ORs] 7.25, 19.51 and 28.80; 95% confidence intervals [CIs] 1.92-27.38, 4.76-79.95 and 6.48-127.92 for 7-13 days, 14-20 days and ≥21 days, respectively; P < 0.01 for all values), baseline platelet count <150 × 10³ /mm³ (adjusted OR, 5.08; 95% CI, 2.06-12.55; P < 0.001), creatinine clearance <30 mL/min (adjusted OR, 4.19; 95% CI, 1.59-11.06; P = 0.004) and concurrent low-dose aspirin therapy (adjusted OR, 2.99; 95% CI, 1.26-7.08; P = 0.013). Baseline platelet count less than 150 × 10³ /mm³ was an independent predictor of early-onset (≤6 days) thrombocytopenia (adjusted OR, 5.07; 95% CI, 1.46-17.58; P = 0.011). Closer monitoring of platelet count is required in patients who receive parenteral linezolid therapy for 7 days or more, and have low baseline platelet counts or impaired renal function.

Reversible recurrent profound thrombocytopenia due to linezolid in a patient with multi-drug resistant tuberculosis: A case report

RATIONALE

Thrombocytopenia caused by linezolid (LZD) is common, with a reported prevalence as high as 11.8%. Platelets typically reach normal levels 7 days after LZD withdrawal. However, recurrent profound thrombocytopenia due to LZD usage and a persistent profound drop in platelet count after LZD withdrawal have not been reported.

PATIENT CONCERNS

We report a case of a 75-year-old woman, who presented with recurrent profound thrombocytopenia induced by LZD treatment for multidrug-resistant tuberculosis (MDR-TB).

DIAGNOSES

Laboratory data and symptoms during and after LZD usage and reusage indicated severe thrombocytopenia.

INTERVENTIONS

LZD was discontinued due to recurrent thrombocytopenia and the platelet count continued to drop for 9 days and returned to normal gradually 16 days after LZD withdrawal and supportive care including platelet transfusion.

OUTCOMES

There was no recurrence of thrombocytopenia during 10 months of follow-up during treatment for MDR-TB with a regimen without LZD.

LESSONS

Recurrent profound thrombocytopenia can happen after several doses of LZD rechallenging. Therefore, reuse of LZD should be avoided after recovery from severe thrombocytopenia due to LZD.

Evaluation of reporting quality for observational studies using routinely collected health data in pharmacovigilance

OBJECTIVES

To appraise the reporting quality of studies which concerned linezolid-related thrombocytopenia referring to REporting of studies Conducted using Observational Routinely collected health Data (RECORD) statement.

METHODS

Medline, Embase, Cochrane library and clinicaltrial.gov were searched for observational studies concerning linezolid-related thrombocytopenia using routinely collected health data from 2000 to 2017. Two reviewers screened potential eligible articles and extracted data independently. Finally, reporting quality assessment was performed by two senior researchers using RECORD statement.

RESULTS

Of 25 included studies, 11 (44.0%) mentioned the type of data in the title and/or abstract. In 38 items derived from RECORD statement, the median number of items reported in the included studies was 22 (inter-quartile range 18-27). Inadequate reporting issues were discovered in the following aspects: validation studies of the codes or algorithms, study size estimation, quantitative variables, subgroup statistical methods, missing data, follow-up/matching or sampling strategy, sensitivity analysis and cleaning methods, funding and role of funders and accessibility of protocol, raw data.

CONCLUSION

This study provides the evidence that the reporting quality of post-marketing safety evaluation studies conducted using routinely collected health data was often insufficient. Future stakeholders are encouraged to endorse the RECORD guidelines in pharmacovigilance.

Predictive score of haematological toxicity in patients treated with linezolid

OBJECTIVE

The aims of our study were to determine the factors associated with developing haematological toxicity (HT) in patients taking linezolid (LZD), to develop a predictive model of HT in these patients, and to evaluate factors associated with 30-day mortality.

METHODS

This was an observational retrospective cohort study of patients treated for at least 5 days with LDZ in 2015. Demographic, clinical and analytical data were collected. Development of HT was defined as a 25% platelet count decrease between the basal count and the 1-week lab test.

RESULTS

Five hundred forty-nine patients were finally included, mean age was 73.3 (SD 15.4) years, and 303 (55.2%) were men. One hundred seventy-five (30.1%) patients achieved HT criteria during treatment with LZD and 41 (7.5%) died. The final model included the presence of cerebrovascular disease (2 points), moderate or severe liver disease (2 points), renal failure (2 points) and basal platelet count less than 90,000/mm3 (8 points). This new model showed an AUC of 0.711 (IC 95% 0.664-0.757; p < 0.001) to predict the development of HT. The probability of HT based on this classification was 6.2, 29.9 and 76.5% for low (0-4 points), intermediate (5-10 points) and high risk (>10 points), respectively. The independent variables associated with 30-day mortality were metastatic solid tumor, lymphoma, age >75 years and HT.

CONCLUSION

This score could help in the identification of patients with high risk for HT and assess the use of an antibiotic other than LZD, an important issue considering its relation with 30-day mortality observed in our study.

Bicytopenia, especially thrombocytopenia in hemodialysis and non-hemodialysis patients treated with linezolid therapy

One of the major adverse events associated with linezolid treatment is pancytopenia. However, there are few reports about the tolerability of linezolid among patients undergoing hemodialysis. This study retrospectively investigated the frequency of bicytopenia (thrombocytopenia and erythropenia) secondary to linezolid treatment in patients undergoing and not-undergoing hemodialysis. In total, 181 patients treated with linezolid from January 2010 to July 2012 at Aichi Medical University Hospital were divided into three groups; patients undergoing hemodialysis (HD group), those with creatinine clearance (CLCR) of <50 mL/min (CLCR < 50 group) and those with CLCR of ≥ 50 mL/min (CLCR ≥ 50 group). The incidence of thrombocytopenia, and changes in the platelet (PLT) counts during and after linezolid therapy were compared among three groups. Thrombocytopenia (<75% of the baseline level) occurred in 125 patients (69.1%). PLT reached its nadir 3-4 days after the end of linezolid therapy. In particular, the PLT nadir in HD group occurred earlier than that in non-HD groups (HD, 11.5 days [4-31 days]; CLCR < 50, 14 days [5-43 days]; CLCR ≥ 50, 15.5 days [4-49 days]; p = 0.11). HD group exhibited the greatest rate of reduction of PLT (HD, 24.0% [0.4-93.8%]; CLCR < 50, 23.8% [0.8-92.9%]; CLCR ≥ 50, 22.4% [0.92-92.9%]; p = 0.003). Finally, HD group exhibited the slowest recovery of PLT to its baseline level (HD, 10 days [5-29 days]; CLCR < 50, 9 days [2-16 days]; CLCR ≥ 50, 8 days [3-17 days]; p = 0.09). The incidence of erythropenia was not significantly different among three groups. These results indicate the need to monitor the PLT count during and after linezolid treatment in patients undergoing hemodialysis.

Risk factors for linezolid-associated thrombocytopenia in adult patients

Objectives

Thrombocytopenia (TP) is a common adverse effect of linezolid (LZD). However, risk factors for LZD-associated TP have been reported in Western patients with relatively heavy body weight. The aim of this study was to determine the risk factors for LZD-associated TP in Asian population.

Materials and methods

A retrospective cohort study was conducted among 101 consecutive patients who received LZD therapy (1,200 mg/day) between July 2003 and December 2013 at a tertiary referral hospital in Tokyo, Japan. The patients with obvious other causes for TP were excluded. The information of target infectious disease, patients’ age, gender, body weight, body mass index, baseline serum creatinine (SCr), baseline platelet count, and treatment duration was collected retrospectively. TP was defined as ≥50 % decrease in platelet count from baseline. Bi- and multi-variate analyses were performed.

Results

A total of 101 patients were included (mean age [SD] 64 [18]; male gender [%], 57 [56]). Median duration [range] of LZD therapy was 14 days [1–67]. LZD-associated TP was identified in 42 patients (42 %). For TP, adjusted odds ratio (OR) [95 % CI] of daily per kg dose (DPKD) and SCr was 1.14 [1.05–1.26] and 1.51 [1.01–2.50], respectively.

Conclusions

Higher DPKD and elevated SCr are significantly associated with LZD-associated TP. These findings suggest that daily dose of LZD should be adjusted using body weight, as typically done in pediatrics, in adults as well. Renal function also should be considered for dose adjustment.