A simplified oral flucloxacillin absorption test for patients requiring long-term treatment.

Patients with severe methicillin-sensitive Staphylococcus aureus infections are effectively treated with initial continuous intravenous (iv) flucloxacillin followed by oral maintenance therapy. As the absorption of oral flucloxacillin is variable, an oral absorption test (OAT) is used to ensure efficacious therapy. The classical OAT (test A) requires overnight fasting, interruption of iv therapy, and is laborious. We designed a simplified OAT (test B) in which iv therapy is continued and oral dosing is performed after a 1-hour fast.