What is the treatment regimen for bacterial tonsillitis using cephalexin?

Cephalexin Treatment Regimen for Bacterial Tonsillitis

For bacterial tonsillitis, cephalexin should be administered at a dose of 20 mg/kg/dose twice daily (maximum 500 mg/dose) for 10 days in patients with penicillin allergy. 1

First-line vs. Second-line Treatment

First-line Treatment Options

• Penicillin V or Amoxicillin are the first-line treatments for bacterial tonsillitis
  • Penicillin V: 250 mg 2-3 times daily for children; 250 mg 4 times daily or 500 mg twice daily for adolescents/adults for 10 days
  • Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) for 10 days 1

Second-line Treatment (Penicillin Allergy)

• Cephalexin: 20 mg/kg/dose twice daily (maximum 500 mg/dose) for 10 days 1
• This is recommended with strong evidence and high quality data for penicillin-allergic patients without immediate hypersensitivity reactions

Important Considerations for Cephalexin Use

Indications for Cephalexin

• Confirmed Group A Streptococcal (GAS) pharyngitis/tonsillitis in penicillin-allergic patients
• Preferred option for patients with severe penicillin allergy who live in regions with high rates of macrolide resistance 1

Contraindications

• Should not be administered to patients with history of anaphylaxis, angioedema, or urticaria after treatment with any form of penicillin due to possible cross-reactions 1

Efficacy

• Cephalexin has demonstrated lower rates of clinical relapse compared to penicillin (3% vs 8%) 2
• Bacteriologic failure rates are also lower with cephalexin (7%) compared to penicillin (11%) 2

Special Populations and Considerations

Children

• Cephalexin capsules should only be used in children capable of swallowing capsules
• For younger children, oral suspension is available 3

Monitoring

• Patients should be followed carefully to detect any side effects or unusual manifestations of drug reactions
• If an allergic reaction occurs, discontinue the drug and treat with appropriate agents 3

Potential Adverse Effects

• Gastrointestinal upset, rash, and urticaria are relatively infrequent 4
• May cause false-positive reaction for glucose in urine tests 3
• Prolonged use may result in overgrowth of nonsusceptible organisms 3

Clinical Pearls and Pitfalls

• Complete the full course: Emphasize to patients the importance of completing the entire 10-day course even if symptoms improve earlier
• Timing: Administer on an empty stomach for optimal absorption
• Cross-allergy risk: Remember that up to 10% of penicillin-allergic persons may also be allergic to cephalosporins 1
• Narrow-spectrum advantage: Cephalexin is preferred over broad-spectrum cephalosporins to minimize development of antibiotic resistance 1

Alternative Options if Cephalexin Cannot Be Used

• Clindamycin: 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days
• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days
• Clarithromycin: 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1

Remember that bacterial confirmation of tonsillitis is important before initiating antibiotic therapy to prevent unnecessary antibiotic use and development of resistance.