Cloxacillin


Concise Prescribing Info
Indications/Uses
Bacterial infections.
Dosage/Direction for Use
Adult : PO Staphylococcal infections resistant to benzylpenicillin: 250-500 mg 6 hourly. Dose and duration of therapy may vary depending on infecting organism, severity of infection and patient’s clinical response. Max: 6,000 mg/day. IM/IV Staphylococcal infections resistant to benzylpenicillin: As cloxacillin Na: 250-500 mg 6 hourly via IM inj, IV inj or IV infusion; may be increased in severe infections. Dose and duration of therapy may vary depending on infecting organism, severity of infection and patient’s clinical response. Max: 6,000 mg/day.
Dosage Details
Oral
Bacterial infections
Adult: Staphylococcal infections resistant to benzylpenicillin: 250-500 mg 6 hourly. Dose and duration of therapy may vary depending on infecting organism, severity of infection and patient’s clinical response. Max: 6,000 mg daily.
Child: ≤20 kg: 25-50 mg/kg daily in divided doses; >20 kg: Same as adult dose.

Parenteral
Bacterial infections
Adult: Staphylococcal infections resistant to benzylpenicillin: As cloxacillin Na: 250-500 mg 6 hourly via IM inj, IV inj or IV infusion; may be increased in severe infections. Dose and duration of therapy may vary depending on infecting organism, severity of infection and patient’s clinical response. Max: 6,000 mg daily.
Child: ≤20 kg: 25-50 mg/kg daily in divided doses; >20 kg: Same as adult dose.
Administration
Should be taken on an empty stomach. Take 1 hr before or 2 hr after meals.
Reconstitution
IM: Dilute with appropriate volume of sterile water for inj to a final concentration of 125 mg/mL or 250 mg/mL. IV inj: Dilute with appropriate volume of sterile water for inj to a final concentration of 50 mg/mL or 100 mg/mL. IV infusion: Dilute with appropriate volume of sterile water for inj to make a concentration of 250 mg/mL; dilute further with a compatible solution (e.g. normal saline solution, dextrose 5% in water). Oral susp: Dilute with appropriate amount of water as specified in the bottle. Shake vigorously until suspended.
Incompatibility
Incompatible with aminoglycosides.
Contraindications
Hypersensitivity to cloxacillin, other penicillins, or cephalosporins.
Special Precautions
Patients with asthma, blood disorders, history of seizure disorder, inflamed meninges. Patients undergoing cardiopulmonary bypass. Children. Renal and hepatic impairment. Pregnancy and lactation.
Adverse Reactions
Significant: Haematologic disorders (e.g. neutropenia, agranulocytosis, anaemia, thrombocytopenia), bacterial or fungal superinfection (including pseudomembranous colitis, C. difficile-associated diarrhoea).
Gastrointestinal disorders: Diarrhoea, loose stools, nausea, vomiting, flatulence, epigastric distress, abdominal pain, stomatitis.
General disorders and administration site conditions: Lethargy, fever.
Immune system disorders: Urticaria, serum sickness-like reaction.
Investigations: Increased serum ALT, AST, alkaline phosphatase.
Musculoskeletal and connective tissue disorders: Twitching.
Nervous system disorders: Myoclonus, seizure.
Psychiatric disorders: Confusion.
Renal and urinary disorders:
Haematuria, proteinuria, renal insufficiency, renal tubular disease, interstitial nephritis.
Respiratory, thoracic and mediastinal disorders: Laryngospasm, bronchospasm, sneezing, wheezing.
Vascular disorders: Hypotension, thrombophlebitis.
Potentially Fatal: Anaphylactoid/hypersensitivity reactions.
MonitoringParameters
Monitor CBC with differential prior to initiation of treatment and weekly thereafter; periodic tests for renal (e.g. urinalysis, BUN, creatinine) and hepatic function. Monitor for signs of anaphylaxis during the 1st dose.
Drug Interactions
Increased serum concentration with probenecid. May increase serum concentration of methotrexate. May interfere with the anticoagulant effect of vitamin K antagonists (e.g. warfarin). Tetracycline may diminish the effect of cloxacillin.
Food Interaction
Food reduces cloxacillin absorption.
Lab Interference
May cause false-positive test results for urine and serum proteins, uric acid and urinary steroids. May interfere with urinary glucose tests using cupric sulfate (Benedict's solution, Clinitest).
Action
Description: Cloxacillin 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. This results to bacterial lysis due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.
Pharmacokinetics:
Absorption: Incompletely absorbed from the gastrointestinal tract. Food reduces absorption by approx 50%. Time to peak plasma concentration: 1-2 hours (oral); 30 minutes (IM).
Distribution: Widely distributed into body fluids and bone. Crosses the placenta and enters breast milk. Little diffusion into the CSF, except when the meninges are inflamed. Plasma protein binding: Approx 94%, mainly to albumin.
Metabolism: Limited.
Excretion: Via urine (approx 35% of an oral dose, as unchanged drug and metabolites) and bile (≤10%). Plasma half-life: 0.5-1.5 hours.
Chemical Structure

Chemical Structure Image
Cloxacillin

Source: National Center for Biotechnology Information. PubChem Database. Cloxacillin, CID=6098, https://pubchem.ncbi.nlm.nih.gov/compound/Cloxacillin (accessed on Jan. 21, 2020)

Storage
Cap: Store below 30°C. Protect from light. Powder for susp: Store below 25°C; refrigerate (2-8°C) after reconstitution and discard after 14 days. Powder for inj: Store between 15-30°C. Reconstituted solution: Store below 25°C (stable for 24 hours) or between 2-8°C (stable for 48 hours).
MIMS Class
ATC Classification
J01CF02 - cloxacillin ; Belongs to the class of beta-lactamase resistant penicillins. Used in the systemic treatment of infections.
References
Anon. Cloxacillin. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 04/11/2019.

Buckingham R (ed). Cloxacillin. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 31/10/2019.

Cloxacillin Capsule/Powder for Syrup (Idaman Pharma Manufacturing Sdn. Bhd.). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. https://www.npra.gov.my/. Accessed 04/11/2019.

Cloxacillin Injectable. Medecins Sans Frontieres. https://medicalguidelines.msf.org/. Accessed 04/11/2019.

Dyna Cloxacillin Capsule (Dynapharm Sdn. Bhd.). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. https://www.npra.gov.my/. Accessed 04/11/2019.

Disclaimer: This information is independently developed by MIMS based on Cloxacillin from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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