Background Linezolid is an antibiotic used for several infections, such as community acquired pneumonia, nosocomial pneumonia and skin and soft tissue infections. Its use has increased over the past years, raising concerns about the incidence in clinical practice of haematological toxicity (HT) related to it.

Purpose To assess linezolid’s related HT and its relationship with risk factors (RF) such as age >65 years, creatinine clearance at the beginning of treatment (ClCr) <30 ml/min/S and duration of treatment (DT) >10 days.

Material and methods A 5 month (July to November 2016) retrospective study was conducted. Inclusion criteria: treatment with linezolid for more than 1 day. Exclusion criteria: paediatric patients, critically ill patients, oncologic patients, and major bleeding or surgery during treatment. Data collected: age, sex, DT, ClCr, requirement of blood transfusion; and haemoglobin (Hb), neutrophil and platelet counts (per mcL) at the beginning and at the end of treatment. It was considered that the patient developed HT if any of the following criteria were met during treatment:

• Decrease of 25% in Hb (g/dL).

• Decrease of 25% in platelet count.

• Decrease from a neutrophil level in rank (1,500–8,000/mcL) to a neutropenic level (<1,500/mcL).

• Requirement of blood transfusion.

The statistical analysis was performed using Stata 13^®.

Results Forty-eight patients. Mean age was 67.8 years (SD=11.3) with 64.6% of males. Mean DT and ClCr were 7.9 days (SD=5.8) and 61.6 mL/min/S (SD=28.9), respectively.

13/48 patients (27.1%) developed HT.

To assess the relationship of HT with the RF, we performed a two-way table and a Fisher’s exact test. The obtained P-values were: age >65 years (p=0.594), ClCr <30 ml/min/S (p=0.415) and DT>10 days (p=0.077).

Conclusion Linezolid’s related HT in our hospital is relatively high (27.1%), but there is no statistically significant relationship (p>0.05) with the proposed RF. However, it seems that with a more statistically poweful study, DT could reach statistical significance. Thus, it is very important to tightly monitor treatments with linezolid in order to avoid HT in our patients.

No conflict of interest