What is the dosage of Cephalexin (Keflex) for cellulitis?

From the Guidelines

For cellulitis, the recommended Keflex (cephalexin) dosage is 20 mg per kg per dose twice daily, with a maximum of 500 mg per dose, for 10 days, as indicated by the strongest and most recent evidence 1. This dosage is based on the guidelines for managing group A streptococcal pharyngitis, which also applies to the treatment of cellulitis.

• Key considerations for Keflex dosage include:
  • Weight-based dosing for children, with a maximum dose of 500 mg per dose
  • Twice-daily administration for optimal efficacy
  • A treatment duration of 10 days, as recommended by the guidelines 1
• It is essential to note that the dosage may vary depending on the severity of the infection and the patient's overall health status.
• Patients should be advised to complete the entire course of antibiotics, even if symptoms improve before finishing, to ensure optimal recovery and prevent antibiotic resistance.
• Additionally, patients should be monitored for potential side effects, such as rash or diarrhea, and advised to contact their healthcare provider if symptoms worsen or do not improve within 2-3 days of treatment.

From the FDA Drug Label

For the following infections, a dosage of 500 mg may be administered every 12 hours: streptococcal pharyngitis, skin and skin structure infections, and uncomplicated cystitis in patients over 15 years of age. The usual adult dose is 250 mg every 6 hours For more severe infections or those caused by less susceptible organisms, larger doses may be needed

The recommended dosage of Keflex (cefalexin) for cellulitis, a type of skin and skin structure infection, is 500 mg every 12 hours or 250 mg every 6 hours for adults. For more severe infections, larger doses may be needed 2.

From the Research

Keflex for Cellulitis Dosage

• The dosage of Keflex (cephalexin) for cellulitis is not explicitly stated in the provided studies, but we can look at the dosages used in the studies for guidance.
• In the study 3, cephalexin was prescribed at a dose of 500 mg, but the frequency and duration of administration are not specified.
• In the study 4, cephalexin was administered at a dose of 500 mg four times daily for 7 days.
• It's worth noting that the studies suggest that cephalexin is effective in treating uncomplicated cellulitis, but the optimal dosage and duration of treatment may vary depending on the individual patient and the severity of the infection.

Treatment Guidelines

• The study 5 recommends that non-purulent, uncomplicated cases of cellulitis be treated with oral antibiotics such as penicillin, amoxicillin, and cephalexin, which provide appropriate targeted coverage of the presumed pathogens.
• The study 6 suggests that antibiotics with activity against community-associated MRSA, such as trimethoprim-sulfamethoxazole and clindamycin, are preferred empiric therapy for outpatients with cellulitis in areas with a high prevalence of community-associated MRSA infections.

Clinical Outcomes

• The study 7 found that 5 days of therapy with levofloxacin was as effective as 10 days of therapy in patients with uncomplicated cellulitis.
• The study 4 found that the use of cephalexin plus trimethoprim-sulfamethoxazole did not result in higher rates of clinical resolution of cellulitis compared to cephalexin alone in the per-protocol analysis, but the modified intention-to-treat analysis suggested a possible benefit of the combination therapy.