Recurrent UTI is most commonly caused by re-infection with the same or different type of bacteria and occurs after resolution of a previously treated infection. Recurrences can be treated with a 3 day or 7 day course of antibiotics. Risk factors for recurrence include sexual intercourse and the use of spermicides. Women with more than 2 UTI in a year should be referred to a urologist or urogynecologist to rule out structural abnormalities. Prophylaxis with an antibiotic once daily has been shown to reduce the risk of recurrence by 95%. Of note, when the antibiotics are discontinued UTI tend to recur and antibiotics do have side effects. For women with recurrent UTI associated with sexual intercourse, a single dose of an antibiotic after intercourse for prophylaxis has been found to be effective. Health behaviors such as urinating after sex, wiping properly and not wearing pantyhose do not appear to reduce the recurrence of UTI.

 

Tip: Certain antibiotics kill off the lactobacilli that keep the genital area healthy. This allows the bacteria that cause UTI to grow. Similarly, spermicides have been found to alter the vaginal microflora increasing the risk of UTI.

Cranberry (Vaccinium macrocarpon) is used widely for the prevention of UTI but should not be used for the treatment of UTI. Originally thought to work by acidifying the urine, subsequent studies have shown that the active ingredient proanthocyanadin inhibits the adherence of bacteria to the cells lining the urinary tract. Studies show efficacy of cranberry against E coli, the main cause of UTI. Blueberry (Vaccinium augustifolium), cranberry's close cousin, has similar active ingredients and anti-adhesion properties although it has been studied less.
In a recent review of the research, 7 studies with cranberry juice and 4 with cranberry tablets (one with both juice and tablets) showed that cranberry significantly reduced symptomatic UTI over a 12 month period compared to a placebo. Dosages, concentrations, and the length of the intervention were variable across studies. There were high drop-out rates by the study participants probably due to their inability to drink large quantities of cranberry juice over long periods of time. Cranberry tablets appeared to be better tolerated and less expensive.

Tip: For my patients with recurrent UTI, I recommend the use of cranberry extract in tablet form. The tablets are more convenient, do not contain sugar and are better tolerated than unsweetened cranberry juice.

Cranberry is available as a sweetened and unsweetened juice and as a concentrated juice extract tablet with or without other active ingredients. One well designed study used Ocean Spray cranberry cocktail 300mL/day (10 oz). Cranberry is safe to use during pregnancy and breastfeeding.