From the FDA Drug Label
For the following infections, a dosage of 500 mg may be administered every 12 hours: ... and uncomplicated cystitis in patients over 15 years of age. Cystitis therapy should be continued for 7 to 14 days. The recommended dose of Keflex for a UTI is 500 mg every 12 hours for 7 to 14 days in patients over 15 years of age 1.
- The dose may be adjusted based on the severity of the infection.
- For more severe infections, larger doses may be needed.
From the Research
For uncomplicated urinary tract infections (UTIs), the recommended Keflex (cephalexin) dosage is 500 mg orally every 12 hours for 7-14 days, as twice-daily dosing has been shown to be as effective as four-times-daily dosing 2. This dosage may vary depending on the severity of the infection and the patient's kidney function. Some key points to consider when prescribing Keflex for UTIs include:
- The importance of completing the full course of treatment, even if symptoms improve, to ensure that the infection is fully cleared
- The need for adequate hydration during treatment to help prevent kidney damage
- The potential for side effects, such as diarrhea, nausea, and allergic reactions, especially in patients with penicillin allergies
- The fact that Keflex may not be the first-line choice for all UTIs, as some common urinary pathogens like E. coli have increasing resistance to this antibiotic 3 It's also important to note that the Infectious Diseases Society of America recommends alternative antibiotics, such as nitrofurantoin or fosfomycin, as first-line treatment for uncomplicated UTIs due to increasing resistance to traditional antibiotics like cephalexin 4. In terms of specific patient populations, elderly patients or those with reduced kidney function may require lower doses of Keflex, and patients with a history of penicillin allergies should be monitored closely for signs of an allergic reaction. Overall, the key to effective treatment of UTIs with Keflex is to use the appropriate dosage and duration of treatment, while also being mindful of the potential for side effects and resistance.