Abstract
Flucloxacillin is a semi-synthetic betalactam antibiotic from the group of isoxazolylpenicillins. It differs from oxacillin by the attachment of one fluorine-chlorine atom to the benzene nucleus which improves absorption from the GIT and prolongs its biological half-life.
Its bioavailability is 54-79 %, volume of distribution is 0.14 +- 0.14 l/kg, and plasma protein binding is 92-95%. It is only about 10 % metabolised, 75 % excreted by the kidneys via glomerular filtration and tubular secretion with a half-life of 0.75-1.14 h.
Dosage ranges from 500 mg every 8 h PO to 2 g every 4 h IV, depending on the severity of the condition and patient characteristics, the total daily dose should not exceed 12 g. Therapeutic monitoring could optimize dosing in patients with increased renal clearance and in diseases caused by less sensitive pathogens, and should be based on determination of its free fraction.