Abstract
Background
Vancomycin and linezolid are antibiotics used in cases where methicillin-resistant Staphylococcus aureus (MRSA) is suspected, including in cases where MRSA is suspected to be the cause of pneumonia. MRSA nasal PCR has been shown to have a high negative predictive value when used to rule out MRSA pneumonia. The purpose of the current study was to determine whether a pharmacist-driven MRSA PCR nasal screening protocol would decrease the time to de-escalation or discontinuation of anti-MRSA therapy when utilized for pneumonia.
Methods
Patients were analyzed in two cohorts, those who received vancomycin or linezolid therapy from October 2012 to February 2013 (before pharmacist-driven MRSA nasal PCR protocol; n = 88) and those who received vancomycin from October 2016 to February 2017 (pharmacist-driven MRSA nasal PCR protocol; n = 105). During the study period, pharmacists were given the authority, via protocol to order an MRSA nasal PCR when vancomycin or linezolid was ordered for the indication of pneumonia. Subsequently, after a negative MRSA nasal PCR, pharmacists would contact the prescriber, and let the prescriber know that the MRSA PCR was negative, and then discontinue anti-MRSA therapy. The primary outcome was duration in hours of active anti-MRSA therapy. Secondary outcomes evaluated were the number of anti-MRSA antibiotic doses ordered, and the number of vancomycin troughs ordered.
Results
Patients in the pre-pharmacist driven cohort received vancomycin or linezolid for a median of 44.19 hours, whereas patients in the pharmacist-driven MRSA PCR protocol period received anti-MRSA therapy for a median of 19.1 hours (P < 0.0001). Additionally, prior to the initiation of the pharmacist-driven MRSA nasal PCR protocol, patients received 349 doses of anti-MRSA therapy, compared with 283 doses in the pharmacist MRSA nasal swab protocol group (P < 0.0001). There were also fewer vancomycin troughs ordered in the pharmacist MRSA nasal PCR protocol group (76 vs. 48, P < 0.0009).
Conclusion
A pharmacist-driven protocol for ordering MRSA nasal PCR led to a statistically significant decrease in the time to discontinuation of vancomycin or linezolid for suspected MRSA pneumonia when the MRSA nasal PCR was negative.
Disclosures
All authors: No reported disclosures.
Emergence of Linezolid-Resistant Mutants in a Susceptible-Cell Population of Methicillin-Resistant Staphylococcus aureus
