Nerbutix (Flucloxacillin)

Nerbutix (flucloxacillin) is used to treat infections caused by susceptible Gram‑positive bacteria, especially in skin, bone and respiratory tracts.

• Skin and soft tissue infections: reduces bacterial load and promotes healing of cellulitis, abscesses and wound infections.
• Bone and joint infections: eradicates Staphylococcus aureus in osteomyelitis and septic arthritis, supporting tissue recovery.
• Respiratory tract infections: clears penicillin‑resistant pneumococcal and staphylococcal pneumonia, improving respiratory function.

• Flucloxacillin binds irreversibly to penicillin‑binding proteins on the bacterial cell wall, inhibiting the transpeptidation step of peptidoglycan synthesis. This disruption weakens the cell wall, leading to osmotic lysis and bacterial death, primarily against penicillin‑ase‑producing Gram‑positive organisms.

Adverse reactions may occur with flucloxacillin therapy.

Common Side Effects

• Nausea: mild gastrointestinal upset.
• Diarrhea: loose stools, often self‑limiting.
• Rash: mild skin erythema or pruritus.
• Elevated liver enzymes: transient hepatic enzyme rise.
• Taste disturbance: metallic or altered taste perception.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction with airway compromise.
• Hepatotoxicity: jaundice or hepatitis, especially with prolonged use.
• Neutropenia: reduced white blood cell count, increasing infection risk.
• Stevens‑Johnson syndrome: severe mucocutaneous reaction.
• Interstitial nephritis: kidney inflammation presenting with renal impairment.

Before initiating therapy, consider patient‑specific factors and monitor for adverse events.

• Allergy assessment: avoid if known hypersensitivity to penicillins.
• Liver function: monitor enzymes in patients with hepatic disease or prolonged therapy.
• Renal function: adjust in severe renal impairment as excretion may be reduced.
• Drug interactions: review concomitant medications that may affect hepatic metabolism.
• Store at ambient temperature: keep below 25°C in the original packaging, protected from moisture and direct sunlight.

Flucloxacillin can affect the pharmacokinetics of several co‑administered drugs.

Major Interactions (Avoid)

• Methotrexate: increased toxicity due to reduced renal clearance.
• Warfarin: potentiation of anticoagulant effect, requiring INR monitoring.

Moderate Interactions (Monitor Closely)

• Oral contraceptives: possible reduction in efficacy, advise backup contraception.
• Tetracyclines: antagonistic effect, may diminish antibacterial activity.
• Probenecid: decreased renal excretion of flucloxacillin, raising plasma levels.