Use of oxazolidinones (linezolid or tedizolid) for the treatment of breast infections. A case series from a tertiary referral hospital.

Abstract

Mastitis is mainly caused by Gram-positive bacteria and usually involves treatment with beta-lactam antibiotics and clindamycin. Oxazolidinones show good results in the treatment of skin and soft tissue infections (SSTIs) due to its pharmacokinetic characteristics. We aimed to describe clinical characteristics and outcomes of patients who received oxazolidinones for the treatment of SSTIs of the mammary tissue. Retrospective single-centre study of patients with a diagnosis of breast infection who received treatment with oxazolidinones as initial or salvage therapy between September 2016 and November 2022. Patients were identified through the pharmacy database. The primary outcome was clinical cure. Twenty-nine patients received oxazolidinones: 27 received linezolid and 2 tedizolid. Median age was 41years (IQR 31.0-56.5) and 28 patients were female. Ten patients (35%) had a history of breast cancer, while three (10%) had an immunosuppressive condition. Microbiological isolation was obtained in 24 individuals (83%). Predominant isolations were methicillin-resistant Staphylococcus aureus (8, 28%) and methicillin-susceptible S. aureus (7, 24%). Twenty-four patients (83%) received oxazolidinones as a salvage therapy, with a median duration of 14days (IQR 10-17). Clinical cure was achieved in 24 patients (83%), while 4 relapsed after a median of 15days (IQR 4-34). One was lost to follow-up. Three patients (10%) were taking selective serotonin reuptake inhibitors, and one of them concurrently received linezolid for 4days with no adverse events recorded. Cytopenia during treatment was observed in 2/12 individuals. Oxazolidinones allowed hospital discharge in 11/13 hospitalized patients. Oxazolidinones could be considered as an alternative for treating breast infections.