The recently announced nationwide shortage of ciprofloxacin creates a dilemma for physicians. Ciprofloxacin is an inexpensive (full-course at Walmart: $4) fluoroquinolone and mainstay UTI treatment. While alternatives exist, some choices are better than others considering emerging E. coli resistance and short-course and cost options.
E. coli causes most UTIs, so recent resistance changes are worth knowing. Twenty percent to 50 percent of community E. coli isolates are resistant to trimethoprim/sulfamethoxazole (TMP/SMX). Clinical failure rates with TMP/SMX are 50 percent to 65 percent if the isolate is resistant and less than 10 percent if susceptible. In vitro resistance matters, a lot for pyelonephritis and less for cystitis.
Fluoroquinolone resistance has increased among community E. coli isolates, a big problem outside the United States. U.S. fluoroquinolone resistance rates have been generally under five percent in healthy women, but are now higher in some places. But warning: Hospital ED and outpatient antibiograms may indicate higher resistance rates related to higher risk for patients who have culture and sensitivity sent.
More frightening is emergence outside this country of extended-spectrum beta-lactamase-producing E. coli infections, resistant to penicillins and cephalosporins and sometimes fluoroquinolones. Yikes! For these pyelonephritis infections, the only option is daily IM/IV ertapenem. Because most antibiotics are displaying resistance problems, routine culture and sensitivity is recommended.
For cystitis, nitrofurantoin (50 mg qid; Macrobid 100 mg bid) has retained good activity, and is effective as a five-day course. Fosfomycin is available as a single 3 g dose sachet, but it's been associated with lower cure rates. A seven-day course is recommended for cephalosporins (e.g., cephalexin 500 mg qid). Levofloxacin (250 mg q day) and TMP/SMX (DS bid), resistance issues noted, can be given as three-day regimens.
For pyelonephritis, there's a new levofloxacin five-day option (750 mg q day), but charges range from $60 to $180 a course. Other options include cephalosporins for 14 days. Neither nitrofurantoin nor fosfomycin can be used to treat pyelonephritis, and most women with uncomplicated pyelonephritis can be treated as outpatients. To hedge against the isolate resistance to oral regimens and delayed prescription filling, I recommend either long-acting ertapenem (1 g IV/IM) or ceftriaxone (1 g IV/IM) and levofloxacin (750 mg PO or IV) before discharge.
Dr. Talan is a professor of medicine at the UCLA School of Medicine and the chairman of emergency medicine and faculty in infectious diseases at Olive View-UCLA Medical Center.
Learn more about infectious diseases at the 23rd Annual Olive View-UCLA EMCME Advances in Emergency Medicine July 8–11 in San Diego; firstname.lastname@example.org.