The simplified oral flucloxacillin absorption test: an accurate method to identify patients with inadequate oral flucloxacillin absorption.

Dijkmans AC, Kweekel DM, Balmforth C, van Esdonk MJ, van Dissel JT, Burggraaf J, Kamerling IMC

The preferred treatment for severe methicillin-sensitive Staphylococcus aureus infections is flucloxacillin, a small-spectrum antibiotic administered intravenously (IV) and orally. However, clinicians switch to the less preferred broad-spectrum antibiotics because of the variable absorption after oral administration of flucloxacillin. A classical oral absorption test (OAT) requires overnight fasting and interruption of IV therapy, and is laborious. In the current study, we investigated whether a simplified OAT can be utilized in a clinical setting to guide antibiotic treatment in patients with severe S. aureus infections. For this, OAT IV therapy is continued and oral dosing is performed after a one-hour fast and implemented after a small study.