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Keflex Indications & Clinical Uses

Evidence-based guide for pediatric prescribing

Keflex (Cephalexin) is a trusted antibiotic that helps children fight bacterial infections. Understanding when and how it's used ensures your child receives the right treatment at the right time for their infection.

Primary FDA-Approved Indications

Keflex (Cephalexin) is widely used in pediatric practice for skin infections, bone infections, urinary tract infections. It is FDA-approved for use in all pediatric ages with typical dosing of 25-50 mg/kg/day divided into 2-4 doses. Clinical evidence supports its safety and efficacy when used as directed.

Skin and Soft Tissue Infections (e.g., Impetigo, Cellulitis)

FDA Approved
Infants >1 month and childrenLevel A (Multiple RCTs)First-line

Cephalexin is a first-line agent for uncomplicated skin infections caused by Streptococcus pyogenes or MSSA (non-MRSA).

Efficacy Data

Success rate: 85-95%
Time to improvement: 48-72 hours

Evidence Sources

FDA Approved Labeling for Keflex (Cephalexin) (2024)
Pediatric Skin and Soft Tissue Infections (e.g., Impetigo, Cellulitis) Treatment Guidelines (2023)

Streptococcal Pharyngitis (Strep Throat)

FDA Approved
Children (especially 5–15 years)Level A (Multiple RCTs)

An alternative to penicillin/amoxicillin for children with non-anaphylactic penicillin allergy; effective against group A strep.

Efficacy Data

Success rate: 85-95%
Time to improvement: 48-72 hours

Evidence Sources

FDA Approved Labeling for Keflex (Cephalexin) (2024)
Pediatric Streptococcal Pharyngitis (Strep Throat) Treatment Guidelines (2023)

Urinary Tract Infections (Cystitis)

FDA Approved
Children (especially girls >2 years)Level A (Multiple RCTs)

Cephalexin is commonly used for uncomplicated lower UTIs in children when susceptibility is confirmed or likely.

Efficacy Data

Success rate: 85-95%
Time to improvement: 48-72 hours

Evidence Sources

FDA Approved Labeling for Keflex (Cephalexin) (2024)
Pediatric Urinary Tract Infections (Cystitis) Treatment Guidelines (2023)

Secondary Clinical Uses

Prophylaxis for Recurrent UTIs

Secondary Use
Infants and children (as directed by specialist)Level B (Single RCT or large non-randomized)

Sometimes used for long-term low-dose prophylaxis in select children with recurrent UTIs under urology/nephrology care.

Efficacy Data

Success rate: 85-95%
Time to improvement: 48-72 hours

Evidence Sources

FDA Approved Labeling for Keflex (Cephalexin) (2024)
Pediatric Prophylaxis for Recurrent UTIs Treatment Guidelines (2023)

Bone and Joint Infections (Follow-up Therapy)

Secondary Use
Children (all ages, under specialist care)Level B (Single RCT or large non-randomized)

May be used as oral step-down therapy for osteomyelitis caused by susceptible organisms once IV therapy has stabilized the infection.

Efficacy Data

Success rate: 85-95%
Time to improvement: 48-72 hours

Evidence Sources

FDA Approved Labeling for Keflex (Cephalexin) (2024)
Pediatric Bone and Joint Infections (Follow-up Therapy) Treatment Guidelines (2023)

Clinical Decision Support

Quick Selection Guide

Symptom Cluster 1

Symptoms:

  • Primary symptoms
  • Associated findings

Likely Diagnosis:

Skin and Soft Tissue Infections (e.g., Impetigo, Cellulitis)

Action:

Initiate Keflex (Cephalexin) therapy

Symptom Cluster 2

Symptoms:

  • Sore throat
  • Fever
  • Swollen glands

Likely Diagnosis:

Streptococcal Pharyngitis (Strep Throat)

Action:

Initiate Keflex (Cephalexin) therapy

Symptom Cluster 3

Symptoms:

  • Primary symptoms
  • Associated findings

Likely Diagnosis:

Urinary Tract Infections (Cystitis)

Action:

Initiate Keflex (Cephalexin) therapy

Red Flags & Warnings

Allergic reaction symptoms

Stop medication and seek care

Immediate

No improvement after 72 hours

Re-evaluate diagnosis

Soon

Clinical Pearls

  • •Keflex (Cephalexin) dosing should be weight-based
  • •Complete full course of treatment
  • •Culture when possible before starting

Alternative Medication Options

Amoxicillin-Clavulanate

Beta-lactam antibiotic

Treatment failure or resistance

Advantages
  • Broader spectrum
Disadvantages
  • More GI effects
Cost: More expensive

Parent Communication Guide

When This Medicine Helps

Understanding the Condition

Keflex (Cephalexin) treats Skin and Soft Tissue Infections (e.g., Impetigo, Cellulitis) by fighting bacteria.

Why We Choose This Medicine

We choose Keflex (Cephalexin) because it's effective and well-tolerated in children.

What to Expect

Most children improve within 48-72 hours.

Monitoring Your Child

Signs the Medicine is Working:

  • Symptoms improve
  • Child feels better
  • Normal activities resume

When to Contact Your Doctor:

No improvement after: 72 hours

Watch for these warning signs:

  • High fever
  • Severe symptoms
  • New symptoms

Common Parent Questions

Can I give with food?

Check specific instructions for your medication.

💡 Ask your pharmacist

Never Use Keflex For

Viral infections

Antibiotics only work against bacteria

Alternatives: Supportive care

Known allergy to Keflex (Cephalexin)

Risk of allergic reaction

Alternatives: Alternative medication

Last updated: 7/21/2025•Evidence quality: 8/10
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