What is the recommended dose of Azithromycin (generic name) for a pediatric patient weighing 18.69kg?

Azithromycin Dosing for an 18.69 kg Child

For a child weighing 18.69 kg, the recommended dose of azithromycin 200 mg/5 mL oral suspension is 5 mL (200 mg) once daily, based on weight-band dosing guidelines. 1

Weight-Based Dosing Calculation

The British Thoracic Society guidelines specify that children weighing 15-25 kg should receive 200 mg once daily. 2 Since this child weighs 18.69 kg, they fall squarely within this weight band. 1

Using the 200 mg/5 mL suspension formulation:

• Volume to administer: 5 mL (1 teaspoon) once daily 3
• This delivers exactly 200 mg per dose 3

Indication-Specific Dosing Regimens

The duration and specific regimen depend on the clinical indication:

For Community-Acquired Pneumonia or Atypical Respiratory Infections

• Day 1: 10 mg/kg (approximately 187 mg, rounded to 200 mg = 5 mL)
• Days 2-5: 5 mg/kg (approximately 93 mg, rounded to 100 mg = 2.5 mL or ½ teaspoon) 1, 3
• Total 5-day course 1

For Acute Otitis Media or Acute Bacterial Sinusitis (3-Day Regimen)

• Days 1-3: 10 mg/kg once daily (200 mg = 5 mL) 3
• Total 3-day course 3

For Streptococcal Pharyngitis (Second-Line Only)

• Days 1-5: 12 mg/kg once daily (approximately 224 mg, rounded to 250 mg) 1
• Note: Azithromycin is second-line for strep throat; penicillin or amoxicillin remain first-line 1

Critical Administration Guidelines

Timing with food: Azithromycin can be taken with or without food. 3

Antacid separation: Do not administer simultaneously with aluminum- or magnesium-containing antacids. Separate administration by at least 2 hours, as antacids reduce drug absorption. 2, 1

Reconstitution: The oral suspension must be properly reconstituted with water before administration. 1

Common Pitfalls to Avoid

• Underdosing for pharyngitis: The standard 10 mg/kg regimen has high recurrence rates for strep throat; use 12 mg/kg daily for 5 days instead. 1
• Using azithromycin as first-line for typical bacterial infections: Azithromycin is specifically indicated for atypical pathogens (Mycoplasma, Chlamydia). For typical bacterial pneumonia caused by S. pneumoniae or H. influenzae, amoxicillin remains the preferred agent. 1
• Prolonged courses: Most indications require only 3-5 days of therapy due to azithromycin's prolonged tissue half-life. 4, 5

Expected Clinical Response

Children on adequate azithromycin therapy should demonstrate clinical improvement within 48-72 hours. 1 If the patient deteriorates or shows no improvement within this timeframe, reassess for complications or alternative diagnoses. 1

Monitoring Considerations

• ECG monitoring: Obtain baseline ECG, repeat at 2 weeks, and after adding any QT-prolonging medications, as azithromycin can prolong the QT interval. 2
• Audiometry: Perform baseline and intermittent audiometry during treatment, particularly with prolonged courses. 2
• Laboratory monitoring: Check liver function tests, renal function, and complete blood count sporadically throughout treatment. 2