One of the most frequent requests for outpatient consultation is for recurrent urinary tract infections (UTIs) in postmenopausal women.
From a medical view-point, low-dose antibiotics (nitrofurantoin or trimethoprim/ sulfamethoxazole) remain the gold standard in prevention; however, many informed doctors are loathe to prescribe them because of concerns about emergence of resistance, as well as the fact that much of the data showing efficacy are from older studies that were done in times when there was less resistance with some of the key urinary pathogens. Many women now have untreatable UTIs because of antibiotic resistance, so non-antimicrobial measures take increasing precedence over taking drugs.
The first non-microbial treatment is use of topical estrogens which have been proven in at least 2 small randomized controlled trials to reduce urinary tract infections by one third to three quarters, so I have been a strong advocate for having women consider the use of topical estrogen. Women who don’t like topical application can use the estradiol vaginal ring, which can be replaced every 3 months. Estrogen thickens the vaginal wall making it much more resistant to infection.
Now, that is one possibility, and it is nice that we are not giving an antimicrobial agent. What has gotten more press lately, with more trials being conducted, is the use of probiotics. The theory is that probiotics reduce the number of pathogenic gram-negative organisms in fecal flora, and perhaps in vaginal flora as well, which would otherwise get past the urethral and mucosal barriers and into the bladder.
A recent trial by a Dutch group examined the use of Lactobacillus taken twice daily vs regular dosing of trimethoprim/sulfamethoxazole for 1 year. This trial included 252 women with a history of about 7 UTIs, on average, per year by self-report. In both groups, reported UTIs were reduced — 2.9 per year for the antibiotic group and 3.3 per year for the Lactobacillus group. The time to the first UTI was 6 months in those taking trimethoprim/sulfamethoxazole and 3 months in those taking Lactobacillus. However, not surprisingly, the women in the probiotic group had significantly less resistance (20%-40% rates of Escherichia coli resistance), but this increased to 80%-95% resistance rates in the women who took trimethoprim/sulfamethoxazole.
Although the study had limitations (they didn’t have full enrollment, they didn’t reach noninferiority measures, and the UTIs were self-reported), it is important in that the number of UTIs seemed to be reduced and, of course, the rates of resistance were lower. Indeed, last year, a trial of Lactobacillus vaginal suppositories published in Clinical Infectious Diseasesshowed a trend toward fewer UTIs.
Cranberry extracts and cranberry juice have been studied for many years.[5,6] In fact, the Dutch group also examined cranberry extract vs trimethoprim/sulfamethoxazole and found much less resistance in the cranberry group (not a surprise).
So, how do l treat these patients? I use 3 approaches to see whether they can yield some improvement. I strongly advocate for consideration of:
Low dose bio-identical estrogen - In this case vaginal estriol (if there is no contraindication from the patient’s gynecologist); this form of estriol is very safe. Vaginal tissue responds typically within 2 weeks.
Lactobacillus - (generally by mouth, because vaginal suppository methods are not yet commercially available).
These approaches result in fewer UTIs and allow me to avoid having my patients use long-term antibiotics or having to reduce the dose of antibiotics for a symptomatic UTI.
Other benefits are improved sleep patterns, (less urinary frequency), along with increased tissue elasticityand appearance and comfort during sex.