What is the typical duration of a Keflex (Cephalexin) treatment course?

Duration of Keflex (Cephalexin) Treatment

The typical duration of Keflex (cephalexin) treatment is 7-10 days for most common infections, though specific conditions may require shorter or longer courses based on the infection site and severity.

Standard Duration Guidelines by Infection Type

Skin and Soft Tissue Infections

• Impetigo or Ecthyma: 7 days 1
• Cellulitis: 5 days, but treatment should be extended if the infection has not improved within this time period 1
• Skin abscesses: 5-10 days after drainage, particularly for recurrent infections 1

Urinary Tract Infections

• Uncomplicated UTIs in children: 7-14 days 1
• Chronic UTIs in adults: 10 days (can be administered twice daily rather than four times daily) 2

Streptococcal Pharyngitis

• Streptococcal throat infections: 10 days 1, 3
  • This longer duration is specifically recommended to prevent complications such as rheumatic fever

Dosing Considerations

The standard adult dosing of cephalexin is:

• 500 mg every 6 hours 1
• For some infections, 500 mg every 12 hours may be sufficient 2

For children, dosing is typically:

• 25-50 mg/kg/day in 4 divided doses 1

Special Considerations

Extended Treatment Situations

Longer courses (beyond 10 days) may be appropriate for patients who:

• Have a slow clinical response to therapy
• Have undrainable foci of infection
• Have bacteremia with Staphylococcus aureus
• Have certain fungal or viral infections
• Are immunocompromised, including those with neutropenia 1

Shorter Treatment Situations

Shorter courses may be appropriate for:

• Patients with rapid clinical resolution following effective source control
• Uncomplicated infections with good clinical response 1

Clinical Decision Points

When deciding on the duration of cephalexin therapy, consider:

1. Type of infection: Streptococcal infections generally require longer treatment (10 days) than simple skin infections (5-7 days)

2. Clinical response: Daily assessment for potential de-escalation of antimicrobial therapy is recommended 1

3. Patient factors: Immunocompromised patients or those with comorbidities may require longer treatment courses

4. Source control: If surgical drainage or removal of infected material was performed, shorter courses may be sufficient

Common Pitfalls to Avoid

• Premature discontinuation: Stopping antibiotics too early can lead to treatment failure and recurrence
• Unnecessarily prolonged therapy: Continuing antibiotics beyond needed duration increases risk of adverse effects and antimicrobial resistance
• Failure to adjust duration based on clinical response: The standard duration should be extended if clinical improvement is not observed

Remember that while these are general guidelines, the most recent evidence suggests that shorter courses (5-7 days) are often sufficient for many uncomplicated infections, while specific infections like streptococcal pharyngitis still warrant the traditional 10-day course.