MKSAP Quiz: Recurrent symptomatic lower UTIs
A 32-year-old woman undergoes consultation for recurrent symptomatic lower urinary tract infections. They have increased in frequency over the past 3 years to a rate of about two times per year. What is the most appropriate management?
A 32-year-old woman undergoes consultation for recurrent symptomatic lower urinary tract infections. They have increased in frequency over the past 3 years to a rate of about two times per year. She has been unable to relate onset to any specific activity. Symptoms resolve quickly with initiation of prescribed antibiotics. She is otherwise well.
Which of the following is the most appropriate management?
A. Daily cranberry tablets
B. Daily D-mannose supplementation
C. Nightly prophylaxis with low-dose ciprofloxacin
D. Self-treatment with nitrofurantoin
E. Urination immediately after sexual intercourse
MKSAP Answer and Critique
The correct answer is D. Self-treatment with nitrofurantoin. This content is available to MKSAP 19 subscribers as Question 36 in the Infectious Disease section. More information about MKSAP is available online.
Self-treatment of each infection with nitrofurantoin is appropriate for this patient (Option D). One-quarter to one-third of women who recover from an episode of cystitis will develop another symptomatic infection within 6 months. Recurrent infections that return within 2 weeks of finishing appropriate antibiotic therapy for uncomplicated cystitis and involve the same cultured bacteria are categorized as relapsed. Recurrent UTIs occurring weeks after successful antibiotic treatment and often involving bacterial strains different from the original are termed reinfection. This type of recurrent UTI is defined by three culture-positive infections in the previous 12 months or two infections within 6 months. Contributing factors for reinfection in premenopausal women include sexual activity, diaphragm and spermicide use, delayed urinary habits, and douching. Diminished estrogen levels and, to a lesser extent, increases in residual bladder urine volume and incontinence play much larger roles in UTIs in postmenopausal women. Episodic self-diagnosis and treatment with a first-line, short-course regimen such as nitrofurantoin is an appropriate initial strategy. Single-dose, postcoital antibiotics are effective in reducing bladder infections if infection is temporally related to coitus; avoidance of spermicides has also proven beneficial.
Anecdotal claims of the benefits of ingestion of daily cranberry juice or tablets (Option A), presumably by inhibiting the adherence of Escherichia coli to uroepithelial cells, lack randomized clinical trial confirmation.
Adhesion blockers such as D-mannose (Option B), theorized to block E. coli adhesion to mannosylated uroepithelial receptors, have not been tested in clinical trials.
Antimicrobial prophylaxis should be reserved for women with frequent recurrent cystitis, defined as three or more infections within 12 months, that has not lessened after attempts using nonantimicrobial strategies. Placebo-controlled trials using nightly doses of antibiotics demonstrated an approximate 95% reduction in infection recurrence. A 6-month trial is recommended; however, the previous pattern of recurrent infection occurs in nearly 50% of women when antibiotic prophylaxis is discontinued. Preferred prophylactic regimens include nitrofurantoin (50-100 mg), trimethoprim-sulfamethoxazole (single strength), and cephalexin (125-250 mg). Ciprofloxacin (Option C) or other fluoroquinolone antibiotics are no longer recommended because of long-term safety concerns.
Urination soon after sexual intercourse (Option E) is often recommended but is an unproven strategy to prevent recurrent UTI.
Key Points
- In women with recurrent cystitis, self-treatment with a first-line, short-course regimen (such as nitrofurantoin) is an appropriate initial strategy.
- Nightly antimicrobial prophylaxis should be reserved for women with three or more urinary tract infections within 12 months.