Cloxacillin
Indications
Cloxacillin is used for:
Staphylococcal infections resistant to benzylpenicillin
Adult Dose
Oral
Adult: 250-500 mg 4 times/day.
Parenteral
Adult: 1-2 g 6 hrly. For more severe infections (e.g. meningitis, endocarditis), 2 g 4 hrly.
Child Dose
Oral
Child: 50-100 mg/kg in divided doses every 6 hr.
Renal Dose
Administration
Should be taken on an empty stomach. Take on an empty stomach 1 hr before or 2 hr after meals.
Reconstitution: IM: The contents of each vial should be dissolved in 1.5 mL of water for inj.
IV: 500 mg to be dissolved in 10-20 mL of water for inj, added to suitable IV fluids if given for i
Contra Indications
Hypersensitivity to cloxacillin and other penicillins.
Precautions
Patient w/ allergies esp β-lactam allergy, asthma, history of seizure disorder. Renal impairment. Pregnancy and lactation. Monitoring Parameters Observe for signs and symptoms of anaphylaxis during 1st dose. Monitor CBC w/ differential (prior to initiating therapy and wkly thereafter), periodic BUN, creatinine, hepatic function.
Pregnancy-Lactation
Interactions
May diminish the effect of BCG and typhoid vaccine. May increase risk of methotrexate toxicity. May diminish the therapeutic effect of Na picosulfate. May decrease serum concentrations of mycophenolate. May prolong bleeding time w/ anticoagulants. Increased serum concentrations w/ probenecid. Tetracycline may antagonise the bactericidal effect of cloxacillin.
Adverse Effects
Side effects of Cloxacillin :
Hypotension, confusion, fever, lethargy, seizure, pruritus, rash, urticaria, abdominal pain, black or hairy tongue, diarrhoea, flatulence, nausea, oral candidiasis, pseudomembranous colitis, stomatitis, vomiting, agranulocytosis, bone marrow depression, eosinophilia, granulocytopenia, haemolytic anaemia, leucopenia, neutropenia, thrombocytopenia, increased alkaline phosphatase, ALT and AST, hepatotoxicity, thrombophlebitis, arthralgia, myalgia, myoclonus, hematuria, interstitial nephritis, proteinuria, renal insufficiency, renal tubular damage, bronchospasm, laryngeal oedema, laryngospasm, sneezing, wheezing, angioedema, allergic reaction, serum sickness-like reaction.
Potentially Fatal: Anaphylaxis.
Mechanism of Action
Cloxacillin inhibits bacterial cell wall synthesis by binding 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. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.