Pharmacology of Mupirocin in Nasal Application in Healthy Volunteers: Monocentric Study

Mupirocin is an old antibiotic used topically since the 1970s. Initially used in the treatment of skin infections for its antistaphylococcal action, it is now part of the decolonization strategy for Staphylococcus aureus (SA) carriage, in association with chlorhexidine. This decolonization strategy has been recommended in France for preoperative cardiac surgery in nasal SA carriers since 2013 by the French Hospital Hygiene Society, and recommended for cardiac and orthopedic surgery in SA carriers by the World Health Organization (WHO) since 2016. This strategy includes nasal decolonization using mupirocin ointment nasally (2 to 3 applications/day), a daily shower with chlorhexidine soap and + /- mouthwashes all over 5 days, often pre-operatively. As a result, mupirocin is now widely used throughout the world, all the more so as, for reasons of ease of organization, many centers use this decolonization procedure universally (i.e. without prior screening for Staphylococcus aureus carriage), thus further increasing the use of this molecule. Mupirocin administration methods are very vague, ranging from 2 to 3 applications per day and the application of "a match head", i.e. 50 mg, to 500 mg per nostril. Mupirocin is bacteriostatic at low doses, becoming bactericidal at higher concentrations; low concentrations could favor the selection of resistance, so using the most effective dosage seems essential. This lack of precision in administration is linked to an almost complete ignorance of the pharmacokinetics of mupirocin and its metabolite (monic acid) after nasal application. It therefore seems essential to conduct a pharmacokinetic study of this molecule, in order to eventually offer patients the regimen with the administration methods offering the best characteristics in terms of dosage and efficacy.