US Pharm. 2017;9(42):4-7.

Urinary tract infections (UTIs) are the most commonly occurring infections, affecting approximately 150 million people worldwide each year.¹ In the United States alone, the societal costs of UTIs are estimated to be $3.5 billion annually.¹ UTIs can affect both men and women, but they are especially common in women of childbearing age.² Most women will experience at least one episode during their lifetime; by 32 years of age, more than half of all women will have reported having at least one urinary tract infection.^2,3 Almost 25% of women will have a recurrent infection within a year.²

A UTI is an infection of the urinary system. UTIs are classified as uncomplicated and complicated.⁴ Uncomplicated UTIs are those occurring in healthy, premenopausal women with no urinary tract abnormalities.³ Complicated UTIs are caused by abnormalities that compromise the urinary tract, such as urinary obstruction, urinary retention, immunosuppression, renal failure, renal transplantation, and presence of foreign objects; pregnancy is another cause.¹ Indwelling catheters account for one million cases, or 70% to 80%, of complicated UTIs in the U.S. per year.¹ Complicated UTIs occur in both sexes and often affect the upper and lower urinary tracts. UTIs are further categorized based on location: lower UTIs (cystitis) and upper UTIs (pyelonephritis). Pharmacists will frequently encounter patients inquiring about relief from UTI-related symptoms, so it is important that they understand the various OTC products marketed for the management of UTIs.

Etiology and Risk Factors

Urine is generally sterile, and the causative agents for most UTIs originate in bowel flora that enter the periurethral area. Most UTIs are caused by one organism; UTIs caused by multiple organisms may indicate contamination. The causative agents are gram-positive and gram-negative organisms, as well as some fungi.¹ The gram-negative bacterium Escherichia coli accounts for almost 90% of all episodes.^3,5 Other common causative agents include Staphylococcus saprophyticus, Klebsiella pneumoniae, Enterococcus faecalis, group B streptococcus, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and Candida species.

Women are more likely to develop a UTI because their urethras are shorter than men’s.⁵ Other risk factors include previous episodes of UTI, sexual intercourse, spermicide use, new sexual partner, reduced mobility, changes in vaginal flora, pregnancy, menopause, diabetes, urinary incontinence, kidney stones, prostate enlargement, and history of UTI in a first-degree relative.^2,4,5 In the elderly population, other risk factors to consider are age-related changes in immune function, increased exposure to nosocomial pathogens, and an increased number of comorbidities.⁶ Certain behaviors are thought to contribute to the development of UTIs, such as frequency of urination and delayed voiding, not voiding pre- and postcoitally, consumption of certain beverages, hot tub usage, douching, wiping patterns, and choice of clothing; BMI may also be a factor. A case-control study found no increased risk of UTI development with these practices.⁷

Clinical Presentation and Diagnosis

Patients with cystitis often present with a frequent, persistent urge to urinate despite passing a small amount, dysuria or a burning sensation during urination, or suprapubic heaviness.⁷ Patients with pyelonephritis often experience flank pain or tenderness, a low fever (<101 F), chills, nausea, vomiting, and malaise with or without symptoms of cystitis.² Patients with a lower or upper UTI may experience hematuria or notice that their urine is cloudy or has a strong odor. Elderly patients tend to present with nonspecific symptoms including altered mental status, change in eating habits, lower abdominal pain, and gastrointestinal symptoms such as constipation.⁶

In most patients who present with signs and symptoms of UTIs, a history of illness is the most important diagnostic tool, especially when symptom onset is sudden or severe and when vaginal discharge and irritation are not present.^2,3 Sometimes, however, UTI diagnosis cannot rely solely on patient symptoms because some patients are asymptomatic; this is more common in older adults than in younger adults.⁶ Laboratory tests, urine-sample tests, and pelvic examinations should be performed in patients with urinary tract symptoms to properly diagnose UTIs.^2,3 Laboratory tests for UTIs include assessments for the presence of bacteriuria and pyuria, nitrite, leukocyte esterase, and antibody-coated bacteria.²

Commercially available dipsticks may be used to detect the presence of a UTI. The pharmacist can recommend an OTC UTI home test kit to determine whether causative agents of UTI are present. After use, the patient should call the physician with the results for evaluation and treatment. The available test kits detect leukocyte esterase and nitrite. Testing for these substances increases overall sensitivity and specificity and reduces the risk of false-negative results.⁸ Self-testing for UTIs has been proven accurate with proper use, but to avoid inaccurate or false results, patients should be advised to obtain a clean-catch urine specimen and to avoid consuming more than 250 mg of vitamin C within 24 hours of testing; women should not test during their menses.^8,9 A strict vegetarian diet, tetracycline, and phenazopyridine may cause inaccurate results.⁹

Preventive Measures

Almost 25% of women experience recurrent episodes of UTI.¹⁰ This is defined as either two uncomplicated UTIs in 6 months or three or more positive cultures within the preceding 12 months.¹⁰ UTIs can occur even when precautions are taken, but pharmacists can recommend preventive measures to reduce a patient’s risk for recurrent infections. If a woman is using spermicide-containing contraceptives, she should be counseled about the possible connection between her contraceptive method and recurrent infections, and an alternative form of contraception should be considered. Although studies have not indicated a correlation, behavioral modifications such as staying hydrated, urinating before and after sexual activity, urinating regularly, using tampons instead of sanitary pads and changing them every 3 hours, wiping from front to back, wearing clean cotton underwear and loose-fitting, breathable clothing, and taking showers instead of baths may be helpful. Topical estrogen therapy in postmenopausal women may help prevent UTI recurrences by altering the vaginal flora.^6,11 Evidence for use of acupuncture and immunoprophylactic regimens is limited.¹²

There is little evidence of the efficacy of natural supplements in the prevention of UTIs. Research suggests that the antioxidant proanthocyanidin and the fructose in cranberries can help prevent bacteria, particularly E coli, from clinging to the walls of the urinary tract.¹³ Cranberry products are available in an array of dosage forms: juice, syrup, capsules, and tablets. Data on the efficacy of cranberry juice in preventing recurrent UTIs are conflicting. A recent Cochrane review determined that cranberry products do not significantly reduce the risk of recurrences compared with placebo.¹³ Similarly, the use of probiotics has also been considered for the prevention of UTIs. Probiotics support the body’s normal flora, and it is theorized that probiotics form a barrier against pathogens ascending the urinary tract, preventing the adherence, growth, and colonization of the urogenital epithelium by uropathogenic bacteria.^14,15 To date, data regarding a protective effect of probiotics against future UTIs have been inconsistent, and additional large, well-designed studies are needed to determine the effectiveness of probiotics.¹⁴

Management: Nonprescription Products

Active ingredients found in OTC urinary tract analgesics include phenazopyridine hydrochloride, methenamine, and sodium salicylate (TABLE 1). Phenazopyridine, which provides relief from the pain, burning, itching, and urgency of UTIs, is available in both prescription (100-mg and 200-mg tablets) and OTC form (95-mg and 97.5-mg tablets). The recommended OTC dosage is two tablets three times daily during or after meals with a full glass of water for up to 2 days. Patients with kidney disease or an allergy to dyes should not take this medication. Patients should be advised that their urine may become reddish-orange in color, which is not harmful but can stain clothing. Common adverse effects (AEs) include headache, dizziness, and upset stomach.

Methenamine (an antibacterial) and sodium salicylate (a nonsteroidal inflammatory drug [NSAID]) work in conjunction with one another; sodium salicylate stabilizes the urine pH, allowing methenamine to slow the growth of bacteria along the urinary tract and control the UTI. The recommended dosage is two tablets three times daily. Patients should be advised not to take this product if they are allergic to salicylates, are on a low-sodium diet or anticoagulant therapy, or have stomach problems.

Patients may also take pain relievers, such as NSAIDs or acetaminophen, for general relief of UTI-associated pain.

Role of the Pharmacist

It is imperative that pharmacists urge patients who present with UTI symptoms to consult with their healthcare provider as soon as possible to receive appropriate care. Pharmacists should counsel patients on nonpharmacologic treatments and present the option of nonprescription products and UTI home test kits. Patients who decide to use UTI home test kits should be advised on how to avoid inaccurate results and to discuss their results with their healthcare provider. Patients who decide to use OTC urinary tract analgesics should be counseled on the recommended maximum dosage and duration and on common AEs. It is imperative to remind patients that these products are intended only to provide relief of pain and other related symptoms until the healthcare provider is seen. These products do not eradicate bacteria or replace the use of antibiotic treatment, and they should not be used as monotherapy.

What Is a Urinary Tract Infection?

What Causes UTIs?

The bacterium that causes most UTIs is Escherichia coli. UTIs can affect both men and women, but they are more common in women. Although UTIs can affect anyone, some factors that can increase your chance of contracting a UTI include sexual intercourse, menopause, spermicides, pregnancy, older age, obesity, genetics, and antibiotic use.

How Can I Tell if I Have a UTI?

Not all UTIs have obvious symptoms, but signs and symptoms of a possible UTI include the need to urinate often, pain and burning sensations during urination, low fever, nausea, vomiting, feeling ill, and back or abdominal pain. You may also notice that your urine is bloody, cloudy, or odorous.

See your doctor immediately if you think you have a UTI, or ask your pharmacist about purchasing a UTI test kit. If you decide to use the take-home UTI test strips, follow the instructions carefully and be sure to discuss your test results with your doctor.

What Can I Take to Relieve Pain?

Phenazopyridine hydrochloride may relieve your pain, burning, itching, and urgency to urinate within 20 minutes. Avoid taking it if you have kidney disease or are allergic to dyes. Do not worry if your urine turns reddish-orange when you take this medication. This common effect is not harmful, but it can stain clothing.

Methenamine (an antibacterial agent) and sodium salicylate (a nonsteroidal inflammatory drug [NSAID]) work together to slow bacterial growth along the urinary tract and to control the UTI. Do not take this medication if you are allergic to aspirin,  are on a low-sodium diet or anticoagulant therapy, or have stomach problems.

You can also take other pain relievers, such as NSAIDs (aspirin, ibuprofen, naproxen, celecoxib) or acetaminophen (Tylenol).

What Natural Supplements Can I Take to Prevent Another UTI?

There is little evidence that natural supplements can prevent UTIs, but you can try cranberry supplements or probiotics. Cranberries contain antioxidants that may help prevent bacteria in the urinary tract from sticking to the walls of the urinary tract. Drinking 10 to 30 oz of cranberry juice per day may be beneficial. Probiotics may help prevent UTIs by supporting the body’s natural microorganisms in the flora.

What Steps Can I Take to Prevent Another UTI?

Drink lots of water, urinate before and after sexual activity, change tampons regularly, wipe from front to back, wear cotton underwear and loose-fitting clothing, and take showers instead of baths.

Remember, if you have questions, Consult Your Pharmacist.

REFERENCES

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11. Beerepoot MA, Geerlings SE, van Haarst EP, et al. Nonantibiotic prophylaxis for recurrent urinary tract infections: a systematic review and meta-analysis of randomized controlled trials. J Urol. 2013;190:1981-1989.
12. Arnold JJ, Hehn LE, Klein DA. Common questions about recurrent urinary tract infections in women. Am Fam Physician. 2016;93:560-569.
13. Jepson RG, Williams G, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2012;(10):CD001321.
14. Schwenger EM, Tejani AM, Loewen PS. Probiotics for preventing urinary tract infections in adults and children. Cochrane Database Syst Rev. 2015;(12):CD008772.
15. Falagas ME, Betsi GI, Tokas T, Athanasiou S. Probiotics for prevention of recurrent urinary tract infections in women: a review of the evidence from microbiological and clinical studies. Drugs. 2006;66:1253-1261.

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