The patient is a 5-year-old male who has recently received amoxicillin for the treatment of AOM. However, re-evaluation reveals no symptomatic improvement after 72 hours (the patient’s mother still reports irritability, fussiness, fever, decreased appetite and poor sleeping habits). The nurse practitioner determines the causative bacteria may be resistant to the current therapy. What should be the next step by the nurse practitioner caring for this child?