What is the treatment for Amy's urinary tract infection (UTI)?

From the Guidelines

I recommend prescribing nitrofurantoin 100mg twice daily for 5 days for Amy's uncomplicated urinary tract infection (UTI). Alternatively, trimethoprim-sulfamethoxazole (Bactrim) 160/800mg twice daily for 3 days is also effective, as suggested by the American College of Physicians in their 2021 guidelines 1. For patients with contraindications to these medications, fosfomycin as a single dose can be used. Amy should take the full course of antibiotics even if symptoms improve quickly, and she should increase fluid intake to help flush bacteria from the urinary tract. Symptoms should begin improving within 48 hours; if they persist or worsen, she should follow up for urine culture and possible antibiotic adjustment. UTIs are typically caused by bacteria (most commonly E. coli) ascending from the urethra to the bladder. These antibiotics work by inhibiting bacterial growth or killing the bacteria directly, with nitrofurantoin and trimethoprim-sulfamethoxazole being preferred first-line options due to lower resistance rates and fewer broad-spectrum effects compared to fluoroquinolones like ciprofloxacin, as noted in the 2011 guidelines by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases 1.

Some key points to consider when treating Amy's UTI include:

• The choice of antibiotic should be based on the local antibiogram and the patient's allergy history and tolerance, as recommended by the AUA/CUA/SUFU guideline in 2019 1.
• The duration of antibiotic treatment should be as short as reasonable, generally no longer than 7 days, as suggested by the AUA/CUA/SUFU guideline in 2019 1.
• Patients with recurrent UTIs may benefit from prophylaxis, and self-care measures such as ensuring adequate hydration and post-coital voiding should be advised, as recommended by the Journal of the American College of Radiology in 2020 1.
• The use of fluoroquinolones should be avoided due to the risk of disabling and serious adverse effects, as warned by the Food and Drug Administration in 2016, and noted in the Journal of Urology in 2018 1.

Overall, the goal of treatment is to alleviate symptoms, prevent complications, and reduce the risk of recurrence, while minimizing the risk of antibiotic resistance and collateral damage.

From the FDA Drug Label

CLINICAL STUDIES Complicated Urinary Tract Infection and Pyelonephritis – Efficacy in Pediatric Patients

The clinical success and bacteriologic eradication rates in the Per Protocol population were similar between ciprofloxacin and the comparator group

Clinical Response at 5 to 9 Days Post-Treatment 95.7% (202/211)

Bacteriologic Eradication by Patient at 5 to 9 Days Post-Treatment* 84.4% (178/211)

The FDA-approved drug for Amy in PO for UTI is ciprofloxacin (PO).

• Clinical Response: 95.7%
• Bacteriologic Eradication: 84.4% 2

From the Research

Treatment Options for UTI

To get Amy in for a UTI, the following treatment options are available:

• Nitrofurantoin: a 5-day course is recommended for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3
• Fosfomycin tromethamine: a 3-g single dose is recommended for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3
• Pivmecillinam: a 5-day course is recommended for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females 3

Considerations for Nitrofurantoin

When considering nitrofurantoin as a treatment option:

• It has been shown to be effective against Escherichia coli and other pathogens of uncomplicated urinary tract infections 4
• It has a low frequency of utilization and high susceptibility in common UTI pathogens, making it a good choice for treatment 5
• However, it can have adverse effects, including pulmonary reactions and polyneuropathy, especially with long-term use 4
• It is contraindicated in the last three months of pregnancy and in patients with renal impairment 4

Comparison with Other Antibiotics

Comparing nitrofurantoin to other antibiotics:

• A 5-day course of nitrofurantoin is equivalent clinically and microbiologically to a 3-day course of trimethoprim-sulfamethoxazole 6
• Nitrofurantoin may be a better option than trimethoprim-sulfamethoxazole due to increasing resistance among uropathogens 6
• In patients with reduced kidney function, nitrofurantoin may not be as effective as other antibiotics, such as ciprofloxacin 7