Preferred drugs are Erythromycin 10 to 12.5 mg / kg orally every 6 hours (maximum 2 g / day) for 14 days Azithromycin 10 to 12 mg / kg orally once a day for 5 days Trimethoprim / sulfamethoxazole may be substituted in patients ≥ 2 months who are intolerant of or hypersensitive to macrolide antibiotics.