What medication should be started for a 27.3kg child?

Medication Selection for a 27.3kg Child with Group A Streptococcal Pharyngitis

For a 27.3kg child with suspected Group A Streptococcal pharyngitis, oral amoxicillin at 50 mg/kg once daily (maximum 1g) for 10 days is the recommended first-line treatment. 1

Diagnostic Considerations

Before initiating treatment, confirm the diagnosis with:

• Rapid antigen detection test (RADT) or throat culture
• Clinical features suggesting streptococcal pharyngitis (fever, tonsillar exudate, tender cervical lymphadenopathy, absence of cough)

Treatment Algorithm

First-line therapy:

• Amoxicillin: 50 mg/kg once daily (maximum 1g) for 10 days 1
  • For a 27.3kg child: approximately 1,365mg daily (can round to 1,350mg or 1,400mg depending on available formulations)
  • Often preferred over penicillin V for children due to better taste acceptance 1

Alternative options if amoxicillin cannot be used:

1. Penicillin V (oral):

   • Dosage: 250mg 2-3 times daily for 10 days 1
   • For a 27.3kg child: standard pediatric dose applies

2. Benzathine penicillin G (intramuscular):

   • Dosage: 600,000 units as a single dose 1
   • Appropriate for this weight (<27kg) 1
   • Consider if oral medication adherence is a concern

For penicillin-allergic patients:

1. Cephalexin: 20mg/kg twice daily (maximum 500mg per dose) for 10 days 1

   • For a 27.3kg child: approximately 546mg twice daily (can round to 550mg)
   • Note: Avoid in patients with immediate-type hypersensitivity to penicillin

2. Clindamycin: 7mg/kg three times daily (maximum 300mg per dose) for 10 days 1

   • For a 27.3kg child: approximately 191mg three times daily (can round to 200mg)

3. Azithromycin: 12mg/kg once daily (maximum 500mg) for 5 days 1

   • For a 27.3kg child: approximately 328mg daily (can round to 330mg)
   • Caution: Be aware of potential GAS resistance to macrolides 1

Important Clinical Considerations

• Timing of treatment: Therapy can be safely postponed for up to 9 days after symptom onset and still prevent acute rheumatic fever 1

• Weight verification: Accurate weight is crucial for pediatric dosing. The provided weight (27.3kg) should be used for calculations rather than estimates 2, 3

• Treatment duration: Complete the full 10-day course (except for azithromycin) even if symptoms resolve earlier to prevent rheumatic fever 1

• Monitoring: Follow up if symptoms persist beyond 48-72 hours of treatment initiation

• Avoid: Do not use sulfonamides, trimethoprim, tetracyclines, or fluoroquinolones as they are not effective against Group A Streptococcus 1

Pitfalls to Avoid

1. Underdosing: Weight-based dosing is critical in pediatrics; using standardized adult doses may result in subtherapeutic levels

2. Incomplete treatment course: Emphasize the importance of completing the full 10-day course even if symptoms resolve quickly

3. Inappropriate antibiotic selection: Using broad-spectrum antibiotics unnecessarily when narrow-spectrum options are effective

4. Failure to verify allergies: Always confirm the nature of any reported penicillin allergy before selecting alternatives

The recommendation for amoxicillin as first-line therapy is based on the most recent guidelines, with excellent efficacy in eradicating Group A Streptococcus and good palatability for children, which improves adherence to the treatment regimen.