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Antimicrobials

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Cloxacillin

Guidelines for use

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1. Spectrum of Activity

Active Against:

  • Methicillin-sensitive Staphylococcus aureus (MSSA)

Not active against:

  • Methicillin-resistant Staphylococcus aureus (MRSA)
  • Coagulase-negative staphylococci
  • Enterococci
  • Gram negative bacteria

2. Clinical Uses

Treatment of methicillin-sensitive staphylococcal infections, including:

  • Bacteremia
  • Endocarditis
  • Meningitis
  • Osteomyelitis
  • Pneumonia
  • Skin and soft tissue infections

3. Precautions

  • The potential for cross-reactivity exists among penicillins, cephalosporins and carbapenems.
  • Pregnancy: not expected to increase risk of major congenital malformations. Human data on cloxacillin, piperacillin/tazobactam, and ticarcillin are limited; however, penicillins as a class are considered safe during pregnancy.
  • Breastfeeding: considered safe during breastfeeding. Monitor nursing infant for GI symptoms. Human data on cloxacillin, piperacillin/tazobactam, and ticarcillin are limited; however, penicillins as a class are considered safe during breastfeeding.

4. Adverse Effects

  • Nausea, vomiting, epigastric discomfort
  • Phlebitis at site of IV infusion
  • Skin rash
  • Hypersensitivity reactions (beta-lactam type) including anaphylaxis
  • Rarely: interstitial nephritis; blood dyscrasias; elevated liver enzymes
  • Intravenous line occlusion – ensure patient has a single lumen PICC inserted if duration of cloxacillin iv is anticipated to be > 7 days.

5. Dosage

IV Therapy:

  • Skin and soft tissue infections: 2 g IV q4 – 6h
  • Bacteremia, endocarditis, meningitis, osteomyelitis: 2 g IV q4h

Oral Therapy:

  • Oral bioavailability is only 50% (when taken on an empty stomach)
  • Use is limited to treatment of mild non-bacteremic infections (e.g., minor SSTI)
  • Dosage: 500 mg PO q6h (on an empty stomach)

Renal Insufficiency: No dosage reduction required

6. Administration

  • Direct Injection: not recommended (unless severe fluid restriction)
  • Intermittent Infusion: infuse 1g over 15 – 30 minutes; 2 g over 30 - 60 minutes
  • Continuous Infusion: 2 g IV q4h each dose infused over 4h
  • Please refer to IV drug monograph on pharmacy intranet page for additional administration information.