GM is a 16 year old female with a urinary tract infection. She is healthy, afebrile, with no use of antibiotics in the previous 6 months and no drug allergies. An appropriate first-line empiric antibiotic choice for her would be: Select one:

Uncomplicated urinary tract infections (UTIs) are common in healthy adolescent and adult females and are most often caused by Escherichia coli. First-line empiric treatment is selected based on likely organisms, local resistance patterns, patient allergies, and severity of illness. In an afebrile patient without recent antibiotic exposure or complicating factors, short-course oral therapy is usually sufficient. The goal is to effectively eradicate the infection while minimizing resistance and unnecessary broad-spectrum antibiotic use. Rationale: A. Nitrofurantoin (Macrobid) is a preferred first-line treatment for uncomplicated lower urinary tract infections. It concentrates well in the urine and is highly effective against common pathogens such as E. coli. It is especially appropriate in healthy, afebrile patients without signs of pyelonephritis because it provides targeted therapy with a lower risk of widespread antibiotic resistance. B. Amoxicillin/Clavulanate (Augmentin) can be used for UTIs in some cases, but it is not usually the preferred first-line empiric option for uncomplicated cystitis. Resistance among common urinary pathogens is higher compared with nitrofurantoin, and broader-spectrum coverage may be unnecessary. It is more often reserved for cases where first-line agents are contraindicated or culture results indicate susceptibility. C. Azithromycin (Zithromax) is not appropriate for routine treatment of uncomplicated UTIs because it has poor activity against the most common urinary pathogens, particularly E. coli. It is more commonly used for respiratory infections and certain sexually transmitted infections. Its pharmacologic profile does not make it effective as standard empiric therapy for cystitis. D. Ciprofloxacin (Cipro) is effective against urinary pathogens but is generally not recommended as a first-line treatment for uncomplicated UTIs in young healthy patients. Fluoroquinolones are reserved for more complicated infections due to concerns about resistance and serious adverse effects such as tendon injury and central nervous system complications. Safer narrow-spectrum options are preferred first.