Thrombocytopenia and anemia associated with linezolid in patients with kidney failure

Coagulation dysfunction events associated with tigecycline: a real-world study from FDA adverse event reporting system (FAERS) database

BACKGROUND

Tigecycline has broad-spectrum anti-bacterial activity and often used for critically ill patients with complicated infections. Only a few clinical studies have reported the coagulation disorder induced by tigecycline. The aim of this study was to investigate the association between tigecycline and coagulation dysfunction using the US Food and Drug Administration Adverse Event Reporting System (FAERS) database.

METHOD

Data from January 2005 to December 2020 in FAERS were retrieved. We investigated the clinical characteristics of the coagulation dysfunction events and conducted disproportionality analysis by using reporting odds ratios (ROR) to compare tigecycline with the full database and other antibiotics.

RESULTS

The total number of reports of coagulation dysfunction related to tigecycline as the primary suspect drug was 223. The median time to event of the coagulation dysfunction events was 10 (interquartile range [IQR] 6.75-13) days. 80.72% coagulation-related adverse events appeared within the first 14 days since the initiation of tigecycline administration. The overall ROR (95% CI) for coagulation-related adverse events was 3.55 (3.08, 4.09). The RORs (95% CI) for thrombocytopenia, hypofibrinogenaemia, coagulopathy, activated partial thromboplastin time prolonged, international normalized ratio increased, prothrombin time prolonged were 8.21 (6.34, 10.62), 705.41 (526.81, 944.54), 30.67 (21.92, 42.92), 42.98 (24.85, 74.31), 4.67 (2.51, 8.71), and 27.99 (15.01, 52.19), respectively. In analyses stratified on comparing tigecycline to vancomycin and daptomycin, significant coagulation dysfunction signals were found with the RORs (95% CI) 2.74 (2.34, 3.22) and 3.08 (2.57, 3.70).

CONCLUSIONS

We found a strong signal of high frequency of reporting coagulation dysfunction in tigecycline. Health professionals should be aware of the potential coagulation disorders risk and monitor coagulation parameters during anti-bacterial therapy with tigecycline, particularly the need to monitor fibrinogen levels.

Linezolid in the treatment of drug-resistant tuberculosis: the challenge of its narrow therapeutic index

INTRODUCTION

Linezolid is an oxazolidinone with potent activity against M tuberculosis, and improves culture conversion and cure rates when added to treatment regimens for drug resistant tuberculosis. However, linezolid has a narrow therapeutic window, and the optimal dosing strategy that minimizes the substantial toxicity associated with linezolid's prolonged use in tuberculosis treatment has not been determined, limiting the potential impact of this anti-mycobacterial agent.

AREAS COVERED

This paper aims to review and summarize the current knowledge on linezolid for the treatment of drug-resistant tuberculosis. The focus is on the pharmacokinetic-pharmacodynamic determinants of linezolid's efficacy and toxicity in tuberculosis, and how this relates to defining an optimal dose. Mechanisms of linezolid toxicity and resistance, and the potential role of therapeutic drug monitoring are also covered. Expert commentary: Prospective pharmacokinetic-pharmacodynamic studies are required to define optimal therapeutic targets and to inform improved linezolid dosing strategies for drug-resistant tuberculosis.

Clinical Experience with Linezolid at a Large Academic Medical Center: A Case Series and Review of the Literature

Purpose

The objectives of this study were to evaluate current patterns of use, microbiologic cure rates, and hematologic toxicities, including identification of risk factors, associated with linezolid utilization at our institution.

Methods

Utilization, clinical, microbiological, and toxicity data were collected prospectively over an 8-month period (August 1, 2006 to March 31, 2007). Binary logistic and multivariate stepwise regression analyses were performed to identify potential risk factors for linezolid-associated thrombocytopenia and anemia.

Results

A total of 116 linezolid courses (102 patients) were identified with a mean duration of therapy of 12.3 days. Appropriate infectious disease service approval and consults were found in 87.9% and 62.1% of the cases, respectively. Bloodstream, urinary tract, and respiratory tract infections accounted for 29%, 21%, and 16% of clinical indications, respectively. Vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and coagulase-negative staphylococci accounted for 43%, 24%, and 7% of clinical isolates, respectively. Overall, the microbiologic cure rate among evaluable patients was 83.8%. Development of thrombocytopenia was found in approximately 30% of linezolid-treated patients. Risk factors for linezolid-associated thrombocytopenia included female gender (OR 5.66, P = .002), serum creatinine (SCr) ≥ 2 mg/dL (OR 4.48, P = .009), intensive care unit admission (OR 3.06, P = .038), and duration of therapy ≥ 28 days (OR 3.76, P = .049).

Conclusion

Utilization patterns may suggest strategies for conserving linezolid, including improved compliance with current approval policies and clinical pathway development. Linezolid microbiological cure rates were similar to those found in the primary literature. Linezolid-associated thrombocytopenia was common and risk factors were identified. Further well-designed prospective studies are needed to confirm these findings. Hosp Pharm-2010;45(12):916-926

Reversible inhibition of mitochondrial protein synthesis during linezolid-related hyperlactatemia

The objective of the present study was to determine the mitochondrial toxicity mechanisms of linezolid-related hyperlactatemia. Five patients on a long-term schedule of linezolid treatment were studied during the acute phase of hyperlactatemia and after clinical recovery and lactate normalization following linezolid withdrawal. Mitochondrial studies were performed with peripheral blood mononuclear cells and consisted of measurement of mitochondrial mass, mitochondrial protein synthesis homeostasis (cytochrome c oxidase [COX] activity, COX-II subunit expression, COX-II mRNA abundance, and mitochondrial DNA [mtDNA] content), and overall mitochondrial function (mitochondrial membrane potential and intact-cell oxidative capacity). During linezolid-induced hyperlactatemia, we found extremely reduced protein expression (16% of the remaining content compared to control values [100%], P < 0.001) for the mitochondrially coded, transcribed, and translated COX-II subunit. Accordingly, COX activity was also found to be decreased (51% of the remaining activity, P < 0.05). These reductions were observed despite the numbers of COX-II mitochondrial RNA transcripts being abnormally increased (297%, P = 0.10 [not significant]) and the mitochondrial DNA content remaining stable. These abnormalities persisted even after the correction for mitochondrial mass, which was mildly decreased during the hyperlactatemic phase. Most of the mitochondrial abnormalities returned to control ranges after linezolid withdrawal, lactate normalization, and clinical recovery. Linezolid inhibits mitochondrial protein synthesis, leading to decreased mitochondrial enzymatic activity, which causes linezolid-related hyperlactatemia, which resolves upon discontinuation of linezolid treatment.