A 30-year-old woman presents with a 1-day history of dysuria, urinary frequency, and suprapubic pain. She is afebrile and has no flank pain. A urine dipstick is positive for leucocytes and nitrites. She is allergic to penicillin (causes anaphylaxis) and trimethoprim (causes a rash). Her eGFR is >60 ml/min/1.73m². What is the most appropriate antibiotic choice?