Cloxacillin

Oral
Staphylococcal infections resistant to benzylpenicillin
Adult: 250-500 mg 6 hourly; may be increased for severe infections. Max: 6,000 mg daily. Dose and duration of treatment may vary based on the infecting organism, infection severity, and patient response. Refer to specific product or local treatment guidelines.
Child: ≤20 kg: 25-50 mg/kg daily in divided doses 6 hourly; >20 kg: Same as adult dose. Dose and duration of treatment may vary based on the infecting organism, infection severity, and patient response. Treatment recommendations may vary among countries and individual products. Refer to specific product or local treatment guidelines.

Parenteral
Staphylococcal infections resistant to benzylpenicillin
Adult: 1,000-2,000 mg 6 hourly; may be increased to 2,000 mg 4 hourly in more severe infections. Doses are given via IV inj, IV infusion, or IM inj. Dose and duration of treatment may vary based on the infecting organism, infection severity, and patient response. Refer to specific product or local treatment guidelines.
Child: Neonates ≤7 days of age <2 kg: 25 mg/kg 12 hourly via IV inj or infusion; ≥2 kg: 25 mg/kg 8 hourly via IV inj or infusion. 7-28 days <2 kg: 25 mg/kg 8 hourly via IV inj or infusion; ≥2 kg: 25 mg/kg 6 hourly via IV inj or infusion. For treatment of meningitis, doses may be doubled and given via IV inj or infusion. ≥1 month <20 kg: 50-100 mg/kg daily (Max: 4,000 mg) divided 6 hourly via IV inj, IV infusion, or IM inj; may be increased for severe infections up to 200 mg/kg daily (Max: 12,000 mg) in divided doses via IV inj or infusion; ≥20 kg: Same as adult dose. Dosage or treatment recommendations may vary among countries and individual products. Refer to specific product or local treatment guidelines.
Reconstitution: Powder/granules for oral solution: Reconstitute powder or granules by adding the appropriate volume of water as specified on the bottle, to make a final concentration of 125 mg/5 mL. IV inj: Reconstitute vial with the appropriate volume of sterile water for inj to yield a final concentration of 50 mg/mL or 100 mg/mL; further dilution in a compatible solution may be needed for IV infusion. IM inj: Reconstitute vial with the appropriate volume of sterile water for inj to yield a final concentration of 125 mg/mL or 250 mg/mL. Refer to specific product guidelines for further instructions on reconstitutions.
Incompatibility: Incompatible with aminoglycosides, tetracyclines, erythromycin, polymyxin B, chloramphenicol, and sulfonamides.

Should be taken on an empty stomach (i.e. At least one hour before food or two hours after food).

Hypersensitivity to cloxacillin, other penicillins, or cephalosporins.

Patient with history of allergy (particularly to drugs or multiple allergens), history of seizure disorder, asthma, syphilis. Renal impairment. Children . Pregnancy and lactation. Monitoring Parameters Perform culture and susceptibility tests; consult local institutional recommendations before treatment initiation due to antibiotic resistance risks. Monitor renal function, LFTs, and haematological status during prolonged and high-dose therapy. Assess for signs and symptoms of anaphylaxis during the initial dose.

Significant: Haematologic disorders (e.g. neutropenia, agranulocytosis, thrombocytopenia), bacterial or fungal superinfection (including pseudomembranous colitis, Clostridium difficile-associated diarrhoea). Gastrointestinal disorders: Diarrhoea, nausea, vomiting, epigastric discomfort, flatulence. General disorders and administration site conditions: Fever. Hepatobiliary disorders: Intrahepatic cholestasis. Immune system disorders: Angioedema. Investigations: Increased AST, ALT, lactate dehydrogenase, and alkaline phosphatase. Musculoskeletal and connective tissue disorders: Joint pains. Nervous system disorders: Seizures (high dose use), headache. Renal and urinary disorders: Acute interstitial nephritis, azotaemia. Skin and subcutaneous tissue disorders: Rash.
Potentially Fatal: Hypersensitivity reactions including anaphylactoid and severe cutaneous adverse reactions.

Bacteriostatic drugs (e.g. chloramphenicol, erythromycin, sulfonamides, tetracyclines) may interfere with the bactericidal effect of cloxacillin. May reduce the efficacy of oral contraceptives (e.g. estrogen), resulting in menstrual irregularities, intermenstrual bleeding, and unplanned pregnancy. May decrease the clearance of methotrexate. Decreased renal tubular secretion with probenecid. May occasionally potentiate the risk of bleeding with oral anticoagulants (e.g. dicumarol, anisindione). Therapeutic effects of BCG, typhoid, and cholera vaccines, and Na picosulfate may be diminished. May reduce the serum concentrations of mycophenolic acid.

Food reduces cloxacillin absorption.

May cause false-positive results with cupric sulfate tests (Benedict's, Clinitest; false-positive urine and serum proteins, uric acid and urinary steroids.

Cloxacillin, an isoxazolyl penicillin, is a bactericidal antibiotic that binds to 1 or more of the penicillin-binding proteins (PBPs) which in turn inhibit the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thereby inhibiting cell wall synthesis. Bacterial lysis eventually occurs due to the ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.
Absorption: Incompletely absorbed from the gastrointestinal tract. Reduced absorption with food. Time to peak plasma concentration: 1-2 hours (oral); approx 0.5-1 hour (IM).
Distribution: Widely distributed to tissues and body fluids, including blister fluid, peritoneal fluid, pleural fluid, middle ear fluid, urine, intestinal mucosa, gallbladder, lung, bone, female reproductive tissues, and bile. Minimal diffusion into the CSF except when meninges are inflamed. Crosses the placenta and enters breast milk. Plasma protein binding: Approx 94%, mainly to albumin.
Metabolism: Metabolised in the liver.
Excretion: Via urine (approx 35%, as unchanged drug and metabolites); bile (up to 10%). Elimination half-life: 0.5-1.5 hours.

Oral: Store below 30°C. Protect from light. Parenteral: Store below 30°C. Protect from light.

Penicillins

J01CF02 - cloxacillin ; Belongs to the class of beta-lactamase resistant penicillins. Used in the systemic treatment of infections.