A patient previously diagnosed with acute sinusitis was trea…

A patient previously diagnosed with acute sinusitis was treated with amoxicillin after presenting with nasal congestion, fever, purulent nasal discharge, headache and facial pain.  At a 10-day follow-up, the patient continues to report persistent purulent discharge, congestion, and facial pain, although the fever has resolved. Given the lack of clinical improvement, what is the most appropriate next step in management the APRN will likely take?