[Linezolid-induced Apoptosis through Mitochondrial Damage and Role of Superoxide Dismutase-1 in Human Monocytic Cell Line U937]

Clinical drug interactions between linezolid and other antibiotics: For adverse drug event monitoring

Detailed data on safety associated with drug-drug interactions (DDIs) between Linezolid (LZD) and other antibiotics are limited. The aim of this study was to investigate the safety signals related to these DDIs and to provide a reference for clinically related adverse drug event monitoring. Adverse event (AE) information from 1 January 2004 to 16 June 2022 of the target antibiotics including LZD using alone or in combination with LZD was extracted from the OpenVigil FDA data platform for safety signal analysis. The combined risk ratio model, reporting ratio method, Ω shrinkage measure model, and chi-square statistics model were used to analyze the safety signals related to DDIs. Meanwhile, we evaluated the correlation and the influence of sex and age between the drug(s) and the target AE detected. There were 18991 AEs related to LZD. There were 2293, 1726, 4449, 821, 2431, 1053, and 463 AE reports when LZD was combined with amikacin, voriconazole, meropenem, clarithromycin, levofloxacin, piperacillin-tazobactam, and azithromycin, respectively. Except for azithromycin, there were positive safety signals related to DDIs between LZD and these antibiotics. These DDIs might influence the incidence of 13, 16, 7, 7, 6, and 15 types of AEs, respectively, and is associated with higher reporting rates of AEs compared with use alone. Moreover, sex and age might influence the occurrence of AEs. We found that the combinations of LZD and other antibiotics are related to multiple AEs, such as hepatotoxicity, drug resistance and electrocardiogram QT prolonged, but further research is still required to investigate their underlying mechanisms. This study can provide a new reference for the safety monitoring of LZD combined with other antibiotics in clinical practice.

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.

LINEZOLID-INDUCED MITOCHONDRIAL TOXICITY PRESENTING AS RETINAL NERVE FIBER LAYER MICROCYSTS AND OPTIC AND PERIPHERAL NEUROPATHY IN A PATIENT WITH CHRONIC GRANULOMATOUS DISEASE

PURPOSE

To report a case with unique changes in the retinal nerve fiber layer observed on optical coherence tomography in a 22-year-old patient on chronic linezolid therapy for recurrent pyogenic liver abscesses with underlying chronic granulomatous disease.

METHODS

History and clinical examination, laboratory evaluation, fluorescein angiography, and optical coherence tomography.

RESULTS

The patient presented with best-corrected visual acuity of 20/200 in the right eye and 20/125 in the left eye. He had moderate optic disk edema and superotemporal field defects bilaterally. Swept-source optical coherence tomography revealed the presence of retinal nerve fiber layer microcystic spaces. Laboratory tests showed no positive findings except for an elevated lactic acid level. Linezolid-induced optic neuropathy was suspected, and the drug was discontinued. Six weeks after termination of oral linezolid therapy, the optic disk edema and the microcystic spaces in the retinal nerve fiber layer resolved, and the best-corrected visual acuity improved to 20/50 in the right and 20/40 in the left eye, respectively.

CONCLUSION

Linezolid is a widely used antibiotic with broad-spectrum action. However, chronic use can lead to mitochondrial toxicity that may have protean manifestations. Ocular examination, particularly of the optic nerve and nerve fiber layer using multimodal imaging, is critical in diagnosing such toxicity.