Cephalexin Dosing for Mastitis Treatment
For adult patients with mastitis, the recommended dose of cephalexin is 500 mg orally three times daily for 7 days. 1
Adult Dosing Recommendations
- The standard oral dose of cephalexin for skin and soft tissue infections, including mastitis, is 500 mg three times daily for adults 1
- For more severe infections, the dose may be increased to 500 mg four times daily 1
- According to the FDA label, the usual adult dose of cephalexin ranges from 1 to 4 g daily in divided doses, with 500 mg every 12 hours being appropriate for skin and skin structure infections 2
Duration of Therapy
- The typical treatment duration for uncomplicated skin infections, including mastitis, is 7 days 1
- If the infection has not improved within 5 days, treatment should be extended or alternative antibiotics considered 1
Microbiology and Efficacy
- Cephalexin is effective against common pathogens causing mastitis, including Staphylococcus aureus and Streptococcus species 1, 3
- Studies have shown that staphylococci are the most frequent isolates from the milk of women with mastitis 3
- Cephalexin has good activity against staphylococci and streptococci but limited activity against anaerobes 1
Alternative Regimens
- In a comparative study, cephradine 500 mg orally every 6 hours for 7 days showed similar efficacy to amoxicillin for the treatment of acute puerperal mastitis 3
- Both treatment failures and recurrences in the amoxicillin group were associated with S. aureus infections, suggesting the superiority of cephalosporins for S. aureus mastitis 3
Clinical Considerations
- Cephalexin is rapidly absorbed after oral administration and achieves good tissue distribution 4
- The drug is primarily excreted unchanged in the urine, with 70-100% of the dose found in the urine 6-8 hours after administration 4
- Patients with creatinine clearance less than 30 ml/min require dose reduction proportional to their reduced renal function 4
Potential Pitfalls and Caveats
- Cephalexin is not effective against MRSA; if MRSA is suspected or confirmed, alternative agents should be considered 1
- Patients with a history of immediate hypersensitivity to penicillin should be cautious when using cephalexin due to potential cross-reactivity 1
- If clinical improvement is not observed within 48-72 hours, reassessment and consideration of alternative antibiotics is warranted 1