How to Prevent Recurrent UTI

This transcript has been edited for clarity. 
Matthew F. Watto, MD: Welcome to The Curbsiders. I’m Dr Matthew Frank Watto here with America’s primary care physician, Dr Paul Nelson Williams.
We are going to talk about recurrent urinary tract infection (UTI). We spoke with an expert, Dr Kellen Choi, who gave us a lot of very practical tips. Remind us, Paul — what is a recurrent UTI?
Paul N. Williams: You need a urine culture to make the diagnosis. The presence of symptoms alone is not sufficient. Sometimes it’s tricky to determine whether this is an incorrectly or incompletely treated UTI vs a recurrent UTI. 
In any case, to make a definitive diagnosis, you need three culture-positive infections in the past 12 months or two culture-positive infections in 6 months. That would constitute a recurrent UTI. It’s a fair number of UTIs, and you have to do your due diligence to make a formal diagnosis. 
It can be a challenge to differentiate between a true UTI and other syndromes that can cause this urinary discomfort, such as pelvic floor dysfunction, pelvic organ prolapse, overactive bladder, and other conditions we see fairly commonly in primary care. We need to make the distinction between those things and what is a true UTI. 
Watto: What size newborn, delivered vaginally, would make us think that maybe the patient has pelvic organ prolapse? 
Williams: This was my favorite pearl of the episode. Our expert, Dr Choi, told us that if the patient has delivered a baby vaginally weighing more than 8 pounds, that increases their risk for pelvic organ prolapse. 
Questions to ask include whether the patient’s symptoms worsen when standing on their feet all day. Do they have a sensation like they are sitting on a golf ball? Do they have to splint or manually assist themselves to start a urine stream? These findings suggest pelvic organ prolapse, which is a different animal and managed differently from recurrent UTI. 
Watto: Everyone reading this will want to know whether cranberry or D-mannose supplements work to prevent UTI. Cranberry and D-mannose are supposed to block the bacteria from adhering to the urothelial lining, but the evidence is mixed on their effectiveness in preventing UTI. In addition to our experts, many review articles say it’s okay for patients to try these supplements, with the understanding that the evidence is limited and uncertain. (Precaution: Patients with diabetes shouldn’t drink cranberry juice cocktail.)
Methenamine hippurate has also been studied for UTI, with similarly mixed results. It requires a low vaginal pH, and a treatment that actually lowers the vaginal pH is vaginal estrogen. This can be used by women with genitourinary syndrome of menopause — typically, postmenopausal women who have signs of vaginal atrophy on exam. Vaginal estrogen is one of our workhorse medications for this condition. 
Dr Choi also talked about prophylactic antibiotics. Have you prescribed these for recurrent UTI in your practice? 
Williams: I would have to get relatively far into the workup before I would feel comfortable starting prophylactic antibiotics. I would have the patient see a urologist or urogynecologist to make sure I haven’t missed any structural abnormalities or anything else that is contributing to the patient’s UTIs before I would just fire off the prophylaxis. But it’s not unusual for me to maintain it. 
Watto: If you have a very reliable patient, you can use the self-start treatment approach. The patient gets a sample for urinalysis and urine culture when they think they have a UTI, and they can start themselves on an antibiotic. That way you will find out whether the UTI was real, and you can tell the patient to stop the antibiotic if the culture is negative. 
For women who are definitely having recurrent UTIs, you have the option of prescribing an antibiotic prophylactically — usually a cephalosporin or trimethoprim-sulfamethoxazole. According to the guidelines and Dr Choi, either of these antibiotics can be used continuously for a 3- to 6-month trial. 
Dr Choi rarely prescribes intermittent dosing of prophylactic antibiotics, mainly because she doesn’t tend to run into the right patients for this approach. When intercourse is suspected to the event leading to a UTI, the patient takes an antibiotic just after intercourse. So, if you have the right patient, you can use this approach with the antibiotics I just mentioned. 
Williams: I wasn’t aware that fosfomycin can be used for continuous prophylaxis. It’s an appealing choice because it’s dosed every 10 days. 
Watto: Fosfomycin is expensive. It’s mentioned in the guidelines, but I’m not sure how many people are prescribing it.
We talked about a lot of great stuff on this episode with Dr Choi, so click here to listen to the full podcast and read the show notes.