What is the recommended dose of azithromycin (Zithromax) for a 5-year-old child weighing 64 pounds?

Azithromycin Dosing for a 5-Year-Old Child Weighing 64 Pounds

For a 5-year-old child weighing 64 pounds (29 kg), the recommended dose of azithromycin is 10 mg/kg (290 mg) on day 1, followed by 5 mg/kg (145 mg) on days 2-5 for most infections.

Dosing Guidelines Based on FDA Labeling

The appropriate azithromycin dosage depends on the specific infection being treated:

Standard 5-Day Regimen

• Day 1: 10 mg/kg = 290 mg (approximately 7.5 mL of 200 mg/5 mL suspension)
• Days 2-5: 5 mg/kg = 145 mg (approximately 3.75 mL of 200 mg/5 mL suspension)
• Total course: 870 mg 1

Alternative 3-Day Regimen (for certain infections)

• Days 1-3: 10 mg/kg daily = 290 mg daily (approximately 7.5 mL of 200 mg/5 mL suspension daily)
• Total course: 870 mg 1

Single-Dose Regimen (for acute otitis media only)

• One-time dose: 30 mg/kg = 870 mg (approximately 22.5 mL of 200 mg/5 mL suspension) 1

Specific Dosing by Indication

1. Respiratory Tract Infections (Community-Acquired Pneumonia):

   • 10 mg/kg (290 mg) on day 1, then 5 mg/kg (145 mg) on days 2-5 2, 1

2. Acute Otitis Media:

   • Option 1: 30 mg/kg (870 mg) as a single dose
   • Option 2: 10 mg/kg (290 mg) once daily for 3 days
   • Option 3: 10 mg/kg (290 mg) on day 1, then 5 mg/kg (145 mg) on days 2-5 1

3. Acute Bacterial Sinusitis:

   • 10 mg/kg (290 mg) once daily for 3 days 1

4. Pharyngitis/Tonsillitis:

   • 12 mg/kg (348 mg) once daily for 5 days 1, 3
   • This higher dose is recommended for pharyngitis/tonsillitis to ensure adequate eradication of Group A streptococcus 3

Administration Guidelines

• Azithromycin suspension can be taken with or without food 1
• For the 200 mg/5 mL concentration, the appropriate volume would be approximately 7.5 mL for a 290 mg dose 1
• The medication should be given at the same time each day to maintain consistent blood levels

Important Considerations

• Weight-based dosing: Always calculate the exact dose based on the child's current weight
• Completion of therapy: Emphasize the importance of completing the full course of treatment, even if symptoms improve before the medication is finished
• Side effects: Most common side effects include abdominal discomfort, diarrhea, nausea, and vomiting 2
• Drug interactions: Azithromycin should not be taken simultaneously with aluminum- or magnesium-containing antacids as they reduce absorption 2

Clinical Efficacy

Studies have demonstrated that both the 3-day and 5-day azithromycin regimens have comparable efficacy and tolerability in children with respiratory infections 4. The 5-day regimen has been shown to be as effective as other antibiotics like amoxicillin/clavulanic acid, clarithromycin, and cefaclor in the treatment of common pediatric infections 5.

By following these dosing guidelines, you can ensure appropriate treatment while minimizing the risk of adverse effects and antimicrobial resistance.