What is the recommended dose of cloxacillin (antibiotic) for treating cellulitis?

Cloxacillin Dosing for Cellulitis

For non-purulent cellulitis in adults, the recommended dose of cloxacillin is 500 mg orally four times daily for 5 days, with extension if the infection has not improved within this time period. 1, 2

First-Line Treatment Options

• Cloxacillin (dicloxacillin) 500 mg orally four times daily is a first-line treatment for typical, non-purulent cellulitis 1, 2
• Other β-lactam alternatives include:
  • Cephalexin 500 mg orally four times daily 1, 2
  • Amoxicillin 500 mg orally three times daily 1
  • Amoxicillin-clavulanate 875/125 mg orally twice daily 2, 3
  • Penicillin (for known streptococcal infections) 1

Duration of Therapy

• A 5-day course of antimicrobial therapy is as effective as a 10-day course for uncomplicated cellulitis if clinical improvement has occurred by day 5 1, 2, 3
• Treatment should be extended if the infection has not improved within the initial 5-day period 2, 4
• For severe infections with systemic symptoms or skin sloughing, longer courses (10-14 days) may be necessary 2, 5

Special Considerations

MRSA Coverage

• Standard β-lactams like cloxacillin do not cover MRSA 1
• Consider MRSA coverage only in specific situations:
  • Cellulitis associated with penetrating trauma 1, 3
  • Evidence of MRSA infection elsewhere 1, 3
  • Purulent drainage 1, 3
  • History of injection drug use 3
  • Failure to respond to β-lactam therapy 1

Severe Infections

• For patients with systemic toxicity or rapidly progressive infection, intravenous therapy is recommended 1, 2
• Hospitalization criteria include:
  • Severe infection with systemic inflammatory response syndrome 2, 3
  • Altered mental status or hemodynamic instability 2, 3
  • Concern for deeper or necrotizing infection 2
  • Immunocompromise 3
  • Failure of outpatient treatment 3

Adjunctive Measures

• Elevation of the affected area to promote drainage of edema and inflammatory substances 1, 3
• Identification and treatment of predisposing factors such as edema, obesity, eczema, venous insufficiency, and toe web abnormalities 2, 3
• Consider systemic corticosteroids in non-diabetic adult patients to reduce inflammation and hasten resolution 2, 3, 6

Prevention of Recurrence

• For patients with 3-4 episodes of cellulitis per year, consider prophylactic antibiotics 2, 3
• Options include oral penicillin or erythromycin twice daily for 4-52 weeks, or intramuscular benzathine penicillin every 2-4 weeks 2, 3

Common Pitfalls to Avoid

• Don't extend treatment unnecessarily beyond 5 days if clinical improvement has occurred 2, 4
• Don't automatically add MRSA coverage for typical non-purulent cellulitis without specific risk factors 1, 3
• Don't forget to examine interdigital toe spaces in lower-extremity cellulitis, as treating fissuring or maceration may reduce recurrence 3
• Don't overlook the importance of elevating the affected area, especially in patients with venous insufficiency or lymphedema 1, 3
• Be aware that allergic reactions to cloxacillin can occur, though cross-reactivity with other β-lactams like amoxicillin and cefuroxime may be uncommon 7