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 dosing for uncomplicated cystitis (UTI) in adults is 500 mg every 12 hours for 7 to 14 days 1.
- The dosage may be adjusted based on the severity of the infection.
- For more severe infections, larger doses may be needed.
From the Research
Keflex (cephalexin) is typically prescribed for uncomplicated urinary tract infections at a dose of 500 mg orally every 12 hours for 7 days, as this dosing regimen has been shown to be as effective as 4-times-daily dosing 2.
Key Considerations
- The most recent study 2 compared twice-daily and 4-times-daily cephalexin dosing for uncomplicated urinary tract infections and found no difference in treatment failure between the two groups.
- Patients should take the full course of antibiotics even if symptoms improve before completion to ensure complete eradication of the infection.
- Keflex should be taken with food if it causes stomach upset, and patients should drink plenty of water during treatment.
- Common side effects include diarrhea, nausea, and potential allergic reactions.
- Patients with a history of penicillin allergy should use caution as there is potential cross-reactivity.
- Kidney function may affect dosing, with reduced doses needed for patients with significant renal impairment.
Additional Guidance
- If symptoms worsen or do not improve within 2-3 days, patients should contact their healthcare provider.
- The choice of antibiotic should be based on the patient's individual risk profile, prior antibiotic treatment, and local susceptibility patterns 3, 4.
- Asymptomatic bacteriuria should only be treated in exceptional situations such as pregnancy or before urological procedures that will probably injure the mucosa of the urinary tract 4.