Flu-K

Approved Indications:

• Treatment of infections caused by penicillinase-producing staphylococci and other susceptible bacteria.
• Skin and soft tissue infections, including:
• Cellulitis
• Impetigo
• Abscesses
• Wound infections
• Bone and joint infections such as osteomyelitis and septic arthritis.
• Respiratory tract infections caused by susceptible organisms, including:
• Pneumonia
• Empyema
• Endocarditis caused by susceptible staphylococci.
• Septicemia due to susceptible bacteria.
• Surgical prophylaxis in procedures with high risk of infection by susceptible bacteria.

Off-label / Clinically Accepted Uses:

• Infections caused by methicillin-sensitive Staphylococcus aureus (MSSA).
• Other serious infections confirmed or strongly suspected to be caused by susceptible staphylococci.

• Adults:
• Oral: Typically 250–500 mg every 6 hours (4 times daily). Severe infections may require up to 1 g every 6 hours.
• Intravenous (IV): 1–2 g every 6 hours depending on severity.
• Pediatrics:
• Oral: 12.5–25 mg/kg every 6 hours. Max 50 mg/kg/day.
• IV: Dose adjusted based on weight and infection severity.
• Elderly:
• Dose adjustments may be necessary due to renal function; generally similar to adult dosing.
• Renal Impairment:
• No adjustment needed for mild to moderate impairment.
• Severe impairment: Use with caution, monitor clinical response.
• Hepatic Impairment:
• No specific dosage adjustment but monitor liver function.
• Administration:
• Oral tablets or suspension should be taken 30 minutes to 1 hour before meals for better absorption.
• IV administration via slow infusion or bolus injection as per clinical judgment.
• Duration:
• Depends on infection type and severity; typically 7-14 days, extended in osteomyelitis or endocarditis.

Flucloxacillin is a beta-lactam antibiotic belonging to the penicillin class. It works by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs) located inside the bacterial cell wall, blocking the cross-linking of peptidoglycan chains necessary for cell wall strength and rigidity. This inhibition causes bacterial cell lysis and death, especially effective against beta-lactamase-producing (penicillinase-producing) Staphylococcus aureus due to its resistance to degradation by beta-lactamases.

• Absorption:
  Well absorbed orally but bioavailability may be reduced by food; hence, recommended before meals.
• Distribution:
  Widely distributed in body tissues and fluids, including bones, sputum, bile, and pleural fluid.
• Metabolism:
  Minimal metabolism in the liver.
• Elimination:
  Primarily excreted unchanged via the kidneys through glomerular filtration and tubular secretion.
  Half-life is approximately 0.75 to 1 hour in healthy adults.

• Pregnancy:
  FDA Category B. Animal studies show no risk; limited human data suggest safety when clearly needed.
• Lactation:
  Flucloxacillin is excreted in breast milk in small amounts. Generally considered safe, but caution advised in nursing infants, especially premature.

• Primary class: Beta-lactam antibiotic
• Subclass: Penicillinase-resistant penicillin

• Known hypersensitivity to flucloxacillin, penicillins, or other beta-lactam antibiotics.
• History of flucloxacillin-associated cholestatic jaundice or hepatic dysfunction.
• Severe hepatic impairment (caution advised).

• Risk of hypersensitivity reactions, including anaphylaxis, especially in patients allergic to penicillins or cephalosporins.
• Monitor liver function due to risk of cholestatic hepatitis, especially with prolonged therapy.
• Use cautiously in patients with renal or hepatic impairment.
• Prolonged use may lead to overgrowth of non-susceptible organisms, including fungi.
• Observe for signs of superinfection.
• Monitor complete blood counts during prolonged therapy.

Common Adverse Effects:

• Gastrointestinal: Diarrhea, nausea, vomiting
• Hypersensitivity: Rash, urticaria, pruritus
• Injection site reactions (IV administration)

Serious/Rare Side Effects:

• Anaphylaxis and severe allergic reactions
• Cholestatic jaundice and hepatic dysfunction
• Hematologic reactions: neutropenia, thrombocytopenia, eosinophilia
• Clostridium difficile-associated diarrhea (rare but serious)

• Probenecid: Decreases renal tubular secretion of flucloxacillin, increasing plasma concentrations.
• Oral contraceptives: Possible reduced efficacy due to alteration of gut flora.
• Other nephrotoxic drugs: Increased risk of renal impairment; monitor renal function.
• Warfarin: May enhance anticoagulant effect; monitor INR.
• Allopurinol: Increased risk of rash when combined with flucloxacillin.

• Current guidelines emphasize flucloxacillin as the first-line agent for MSSA infections and skin infections caused by penicillinase-producing staphylococci.
• Monitoring for hepatotoxicity remains an important precaution.
• No recent major changes in dosing or approved indications.
• Continued warnings on careful patient selection in those with liver disease.

• Store at room temperature between 20°C and 25°C (68°F to 77°F).
• Protect from moisture and light.
• Keep the medication in the original container with the lid tightly closed.
• Oral suspensions: Store refrigerated (2°C to 8°C) after reconstitution and discard after prescribed duration (usually 7 days).
• Do not freeze.
• Keep out of reach of children.