From the Guidelines
Keflex should be dosed at 20 mg per kg per dose twice daily, with a maximum of 500 mg per dose, for 10 days in patients with penicillin allergy. This dosing recommendation is based on the strongest and most recent evidence available, specifically the 2013 guideline update for managing group A streptococcal pharyngitis published in the American Family Physician 1.
Key Considerations
- The recommended dose is weight-based, with a maximum dose of 500 mg per dose, to ensure efficacy while minimizing potential side effects.
- The treatment duration is 10 days, which is consistent with the standard treatment duration for group A streptococcal pharyngitis.
- It is essential to note that Keflex is a first-generation cephalosporin antibiotic and may not be suitable for patients with a history of severe allergic reactions to penicillin or other cephalosporins.
Important Details
- Patients with reduced kidney function may require dose adjustments to prevent accumulation of the drug and potential toxicity.
- Common side effects of Keflex include diarrhea, nausea, and allergic reactions, and patients should be monitored for these adverse effects.
- Drug interactions, particularly with probenecid, should be carefully evaluated before initiating Keflex therapy, as they can increase Keflex blood levels and potentiate side effects.
From the FDA Drug Label
Adults The adult dosage ranges from 1 to 4 g daily in divided doses. The usual adult dose is 250 mg every 6 hours 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. Pediatric Patients The usual recommended daily dosage for pediatric patients is 25 to 50 mg/kg in divided doses
The recommended dosing for Keflex (cefalexin) is:
- Adults: 250 mg every 6 hours, or 500 mg every 12 hours for certain infections, with a total daily dose of 1 to 4 g
- Pediatric patients: 25 to 50 mg/kg per day in divided doses 2
From the Research
Keflex Dosing Information
- Keflex, also known as cephalexin, is an effective antibiotic for the treatment of streptococcal and staphylococcal skin infections 3.
- The standard dosing for Keflex is typically twice daily, which enhances medication compliance due to its resistance to degradation by gastric acid and uniform absorption 3.
- For the treatment of skin and soft tissue infections, Keflex can be used in various formulations, including suspension, which is well accepted by young children 3.
- The choice of antibiotic, including Keflex, may depend on cost factors, as many antibiotics are similar in efficacy, palatability, and adverse reactions 3.
Treatment of Specific Infections
- For mild and localized impetigo, topical antibiotics may be used, while widespread or severe cases may require systemic antibiotics like Keflex 4.
- Folliculitis, furunculosis, and carbuncle can be treated with topical or systemic antibiotics, including Keflex 4.
- Erysipelas and cellulitis may require systemic antibiotics like Keflex, depending on the severity and suspected causative organism 4.
Comparison with Other Antibiotics
- Keflex has been compared to other antibiotics, such as doxycycline, in the treatment of presumed streptococcal skin and soft tissue infection, with similar clinical failure rates observed 5.
- Doxycycline may represent a reasonable therapeutic alternative to Keflex in regions with low tetracycline resistance 5.