A 16-month-old boy is brought in by his parents with fever, irritability and lethargy. On examination, the neck is stiff. He hasn't received any vaccinations. CSF gram stain done and antibiotics were staed immediately. The organism seen in the above gram stain grows on chocolate agar but not blood agar. No one else in the family is ill. All of the following are true about the treatment of the above disease in this patient except: -