FLUCLOXACIILLIN BP 250MG CAPSULES

Indications

• Skin and soft tissue infections
• Respiratory tract infections
• Osteomyelitis
• Endocarditis
• Bone and joint infections

Mechanism of action

Flucloxacillin exerts its antibacterial effect by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs), which are essential for the cross-linking of peptidoglycan layers in the bacterial cell wall. This inhibition disrupts the integrity of the cell wall, leading to cell lysis and death. Flucloxacillin is resistant to the action of staphylococcal beta-lactamases, which makes it effective against certain penicillin-resistant strains.

Pharmacodynamics

Flucloxacillin demonstrates bactericidal activity against susceptible organisms. Its efficacy is influenced by the time that serum concentrations exceed the minimum inhibitory concentration (MIC) for the target pathogen. The drug is generally effective against Gram-positive cocci, particularly those that produce penicillinase. Flucloxacillin's spectrum of activity includes Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus pyogenes, among others.

Pharmacokinetics

Flucloxacillin is administered orally or intravenously. It is rapidly absorbed from the gastrointestinal tract, with peak plasma concentrations occurring within 1 to 2 hours after oral administration. It has a bioavailability of approximately 50 to 70%. The drug is widely distributed in body tissues and fluids, including bone and synovial fluid, and has a volume of distribution of about 0.2 L/kg. Flucloxacillin is primarily excreted by the kidneys; renal clearance is significant, and about 60% of the dose is excreted unchanged in the urine. The half-life of flucloxacillin ranges from 0.5 to 1 hour, necessitating multiple dosing to maintain therapeutic levels.

Contra-indications

• History of hypersensitivity to flucloxacillin, penicillins, or other beta-lactam antibiotics
• Severe hepatic impairment
• History of cholestatic jaundice or hepatic dysfunction associated with flucloxacillin

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Rash
• Allergic reactions including anaphylaxis
• Hepatitis
• Cholestatic jaundice
• Renal impairment

Interactions

• Probenecid may increase plasma concentrations of flucloxacillin
• Methotrexate may have increased toxicity when used with flucloxacillin
• Interactions with oral anticoagulants may occur, monitoring recommended

Precautions

• Caution in patients with renal impairment
• Use with caution in patients with a history of gastrointestinal disease, particularly colitis
• Monitor liver function tests in patients receiving prolonged therapy

Pregnancy

Flucloxacillin is generally considered safe in pregnancy. It is a category B drug, meaning no evidence of risk in humans has been observed.

Breast-feeding

Flucloxacillin is excreted in breast milk in small amounts. It is generally considered safe during breastfeeding, but monitoring for adverse effects in the infant is advised.

Storage

Store at room temperature, away from moisture and heat. Reconstituted solutions should be stored in a refrigerator and used within the recommended timeframe.

Formulations

• Capsules
• Oral suspension
• Injection