Can I give cephalexin (a cephalosporin antibiotic) to a child with pneumonia?

Cephalexin is NOT recommended for pediatric pneumonia

Cephalexin should not be used as first-line or even second-line therapy for pneumonia in children, as it lacks adequate coverage against the most common causative pathogens and is not included in any major pediatric pneumonia guidelines. 1

Why Cephalexin is Inappropriate for Pneumonia

Inadequate Pathogen Coverage

• Cephalexin is a first-generation cephalosporin that has poor activity against Haemophilus influenzae, a key pathogen in pediatric pneumonia, with documented failure rates of 50% in H. influenzae infections 2
• The drug lacks coverage against atypical pathogens (Mycoplasma pneumoniae, Chlamydophila pneumoniae) which are increasingly prevalent in children aged 5 years and older 1
• Cephalexin has insufficient activity against penicillin-resistant Streptococcus pneumoniae, which requires higher-dose beta-lactams or third-generation cephalosporins 1

Guideline-Based Alternatives

For outpatient treatment (mild pneumonia):

• First-line: High-dose amoxicillin (80-90 mg/kg/day divided twice daily) for children of all ages when S. pneumoniae is suspected 1
• Second-line: Amoxicillin-clavulanate (90 mg/kg/day of amoxicillin component in 2 doses) if first-line fails or for children under 3 years with inadequate H. influenzae type b vaccination 1, 3
• Add macrolide: Azithromycin (10 mg/kg day 1, then 5 mg/kg days 2-5) for children ≥5 years or when atypical pneumonia is suspected 1

For inpatient treatment (severe pneumonia):

• Fully immunized children: IV ampicillin or penicillin G; alternatives include ceftriaxone or cefotaxime (NOT cephalexin) 1
• Incompletely immunized or significant local resistance: IV ceftriaxone or cefotaxime plus azithromycin 1
• If oral cephalosporin needed: Use cefpodoxime, cefprozil, or cefuroxime (second/third-generation agents), NOT cephalexin 1, 4

When Cephalosporins ARE Appropriate

Third-Generation Cephalosporins

• Ceftriaxone (50-100 mg/kg/day IV once daily) is highly effective for severe pneumonia and can facilitate early discharge with outpatient IM administration after initial stabilization 5
• Cefotaxime provides similar coverage and is recommended for hospitalized children with severe disease 1

Second-Generation Cephalosporins

• Cefuroxime (oral or IV) has documented efficacy in pediatric pneumonia and adequate coverage against S. pneumoniae and H. influenzae 4
• Cefuroxime can be used for sequential therapy (IV to oral transition) after 24-72 hours of clinical improvement 4

Critical Clinical Pitfalls

• Do not confuse first-generation cephalosporins (cephalexin) with second/third-generation agents - they have fundamentally different spectrums of activity 1, 4
• Cephalexin is appropriate for skin/soft tissue infections and UTIs, but its use in respiratory infections is limited to upper respiratory tract infections (pharyngitis, tonsillitis) caused by beta-hemolytic streptococci, NOT pneumonia 2, 6
• If a child fails amoxicillin therapy, switch to amoxicillin-clavulanate or add a macrolide - do not use cephalexin 1, 3
• For penicillin-allergic patients, use a macrolide (azithromycin, clarithromycin) or respiratory fluoroquinolone (levofloxacin in adolescents), NOT cephalexin 1

Treatment Monitoring

• Re-evaluate after 48-72 hours if no clinical improvement (decreased fever, improved respiratory effort, better oral intake) 1
• Consider hospitalization if outpatient therapy fails, oxygen saturation <92%, or signs of respiratory distress develop 1
• Switch to IV therapy if oral absorption is compromised (vomiting) or severe illness is present 1