A 34-year-old otherwise healthy woman presents to your prima…

A 34-yeаr-оld оtherwise heаlthy wоmаn presents to your primary care office with a 2-day history of dysuria, urinary urgency, and urinary frequency that has progressed to fever, chills, nausea, and left-sided flank pain. She reports mild nausea but has been able to tolerate oral fluids and medications. She denies vomiting, pregnancy, diabetes, or a history of recurrent urinary tract infections.Vital signs are as follows:Temperature: 100.8°F (38.2°C)Blood pressure: 118/72 mmHgHeart rate: 92 bpmRespiratory rate: 16 breaths/minOxygen saturation: 99% on room airPhysical examination demonstrates left costovertebral angle tenderness. Urinalysis reveals positive nitrites, positive leukocyte esterase, pyuria, bacteriuria, and WBC casts. A urine culture is obtained before initiating treatment. Based on the patient's presentation, which of the following is the most appropriate next step for treatment plan?