Treatment Duration for Group B Streptococcus UTI with Cephalexin
For Group B Streptococcus (GBS) urinary tract infections treated with cephalexin, prescribe 7 days of therapy for uncomplicated cystitis and 7-14 days for febrile UTI or pyelonephritis.
Duration Based on Clinical Presentation
Uncomplicated Cystitis (Non-Febrile)
- Treat for 7 days when the patient has dysuria, frequency, or urgency without fever or systemic symptoms 1
- This duration applies to both adult and pediatric patients with lower urinary tract symptoms only 2, 1
- Shorter courses (3-5 days) are recommended for other agents like amoxicillin-clavulanate, but cephalexin-specific data supports 7 days as the standard 1
Febrile UTI or Pyelonephritis
- Treat for 7-14 days when fever is present or upper tract involvement is suspected 2
- For infants and children 2-24 months with febrile UTI, the American Academy of Pediatrics specifically recommends 7-14 days of antimicrobial therapy 2
- Choose 7 days when clinical response is prompt (defervescence within 72 hours) 1, 3
- Extend to 10-14 days if fever persists beyond 72 hours or symptoms fail to improve 1, 3
Critical Treatment Considerations
Pre-Treatment Steps
- Always obtain urine culture before initiating therapy to confirm GBS and rule out resistance 3
- Document fever presence, as this fundamentally changes treatment duration from 7 days to 7-14 days 2, 1
Dosing Strategy
- Cephalexin 500 mg twice daily is as effective as four times daily dosing for uncomplicated UTI and improves adherence 4
- The drug achieves high urinary concentrations and retains full activity against typical uropathogens including GBS 5
Monitoring Response
- Assess clinical response within 72 hours of starting therapy 3
- If fever persists or symptoms worsen, extend duration to 10-14 days and consider imaging for complications 1, 3
- Routine "proof of cure" cultures are not recommended if clinical response is adequate 2
Common Pitfalls to Avoid
- Do not treat for less than 7 days - evidence shows 1-3 day courses are inferior for febrile UTIs 1
- Do not automatically prescribe 14 days - this increases adverse effects without improving outcomes when clinical response is prompt 1, 3
- Do not treat asymptomatic bacteriuria unless the patient is pregnant or undergoing urologic procedures with expected mucosal bleeding 2, 1
- Do not fail to document fever status - this single factor determines whether 7 days versus 7-14 days is appropriate 2, 1