Flucloxacillin

Flucloxacillin

Clinical data
AHFS/Drugs.com	Micromedex Detailed Consumer Information
Pregnancy category	AU: B1
Routes of administration	Oral, IM, IV, intrapleural, intraarticular
ATC code	J01CF05 (WHO) QJ51CF05 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) UK: POM (Prescription only)
Pharmacokinetic data
Bioavailability	50–70%
Metabolism	Hepatic
Biological half-life	0.75–1 hour
Excretion	Renal
Identifiers
IUPAC name (2S,5R,6R)-6-({[3-(2-chloro-5-fluorophenyl)-5-methylisoxazol-4-yl]carbonyl}amino)-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid
CAS Number	5250-39-5 Y
PubChem CID	21319
DrugBank	DB00301 Y
ChemSpider	20037 Y
UNII	43B2M34G2V
KEGG	D04196 Y
ChEBI	CHEBI:5098 Y
ChEMBL	CHEMBL222645 Y
ECHA InfoCard	100.023.683
Chemical and physical data
Formula	C19H17ClFN3O5S
Molar mass	453.87 g/mol
3D model (Jmol)	Interactive image
SMILES O=C(O)[C@@H]3N4C(=O)[C@@H](NC(=O)c2c(onc2c1c(F)cccc1Cl)C)[C@H]4SC3(C)C
InChI InChI=1S/C19H17ClFN3O5S/c1-7-10(12(23-29-7)11-8(20)5-4-6-9(11)21)15(25)22-13-16(26)24-14(18(27)28)19(2,3)30-17(13)24/h4-6,13-14,17H,1-3H3,(H,22,25)(H,27,28)/t13-,14+,17-/m1/s1 Y Key:UIOFUWFRIANQPC-JKIFEVAISA-N Y

Flucloxacillin (INN) or floxacillin (USAN) is a narrow-spectrum beta-lactam antibiotic of the penicillin class. It is used to treat infections caused by susceptible Gram-positive bacteria. Unlike other penicillins, flucloxacillin has activity against beta-lactamase-producing organisms such as Staphylococcus aureus as it is beta-lactamase stable. However, it is ineffective against methicillin-resistant Staphylococcus aureus (MRSA). It is very similar to dicloxacillin; they are considered interchangeable. While no longer used in the United States, Flucloxacillin is supplied under a variety of trade names in other countries, including Floxapen (Beecham, now GSK), Flopen (CSL), Staphylex (Alphapharm), Softapen (Rephco Pharmaceuticals Limited), Flubex (Beximco Pharmaceuticals Ltd, Bangladesh), and Flupen (for state use only in South Africa).

It is most commonly used to treat infections.

Flucloxacillin can also be used to prevent infections during major surgical procedures, particularly in heart or orthopedic surgery.

Like other β-lactam antibiotics, flucloxacillin acts by inhibiting the synthesis of bacterial cell walls. It inhibits cross-linkage between the linear peptidoglycan polymer chains that make up a major component of the cell wall of Gram-positive bacteria.

Flucloxacillin is insensitive to beta-lactamase (also known as penicillinase) enzymes secreted by many penicillin-resistant bacteria. The presence of the isoxazolyl group on the side chain of the penicillin nucleus facilitates the β-lactamase resistance, since they are relatively intolerant of side chain steric hindrance. Thus, it is able to bind to penicillin-binding proteins and inhibit peptidoglycan crosslinking, but is not bound by or inactivated by β-lactamases.