Patients may be given either of the following: Erythromycin 10 mg / kg orally or by injection every 6 hours (maximum, 2 g a day) for 14 days Procaine penicillin G IM (300, 000 units every 12 hours for those weighing ≤ 10 kg and 600, 000 units every 12 hours for those weighing > 10 kg) for 14 days When patients are able to tolerate oral antibiotics, they should be switched to penicillin 250 mg orally 4 times a day or erythromycin 500 mg (10 mg / kg for children) orally every 6 hours for a total of 14 days of treatment.