Antimicrobial stewardship and linezolid

Pauline Guillard, Arnaud de La Blanchardière, Vincent Cattoir, Marc-Olivier Fischer, Renaud Verdon, Guillaume Saint-Lorant

Background Since 2002, linezolid, the first representative of the oxazolidinone class, has been widely prescribed, sometimes outside of approved indications. However, several cases of clinical outbreaks due to linezolid-resistant organisms have been reported, and its relatively high cost represents an economic challenge for hospital settings. Objectives The aim of this study was to assess the impact of different actions conducted by an antimicrobial stewardship team (AST) to control over-prescription of linezolid with regard to the defined daily dose (DDD) per 1,000 inhabitants per day. Setting This work was conducted in a 1,495-bed hospital from 2009 to 2013. An AST, gathering the departments of pharmacy, microbiology, and infectious diseases, assessed the pertinence of linezolid use and associated effect on the prescriber. Method A retrospective study was conducted throughout 2009. Three different evaluations were prospectively carried out, each for 3 months, between 2011 and 2013. Main outcome measure The indicators chosen to monitor the consumption of linezolid were the DDD per 1,000 inhabitants per day, which enabled a comparison to be made between hospitals from 2004 to 2012, and of the pertinence of its prescription by different departments. Results From 2009 to 2013, 239 patients were evaluated through three 3-month stages. Prescriptions were for off-label use in 45 % of cases. Prescriptions were considered appropriate in 60 % of cases. Unsuitable treatment was either modified or discontinued (62 and 38 % of cases, respectively). Mean duration of linezolid treatment was 8 days, i.e. below the national mean duration reported in the literature. To highlight the impact of action taken by the team, a consensual strategy to treat ventilator-acquired pneumonia was elaborated with principal prescribers. Throughout the study, the mean DDD per 1,000 inhabitants per day increased very slowly and was lower than the eleven other French hospitals, which were secondarily included in this study. Conclusion The multidisciplinary approach that was adopted for therapeutic education and delivery control led to an improvement in the proper use of linezolid. Similar strategy should be extended to other antimicrobial agents, such as carbapenems, for which both cost and risk of resistance emergence are of major concern.