Detecting and Treating UTIs

The symptoms of urinary tract infections send patients to the pharmacy counter for relief.

Pharmacists are likely to encounter patients seeking advice regarding the symptoms, treatment, and prevention of urinary tract infections (UTIs), which are one of the most common medical complaints among women 18 years and older.^1,2

UTIs account for approximately 4 million office visits per year to primary health care providers.² Because women have a shorter urethra than men, they are more susceptible to UTIs due to the retrograde migration of bacteria from the skin.^1-3 UTIs are estimated to affect 20% of women at some point during their lifetimes.^1,3

UTI recurrences are common, and at least 25% of women who have a UTI will have another infection within a year.⁴ An estimated 95% of UTIs occur when bacteria ascend the ureter to the kidney.⁴ Approximately 80% of uncomplicated UTIs are caused by Escherichia coli, with the remainder caused by microorganisms such as Staphylococcus saprophyticus, Proteus species, Klebsiella species, Enterococcus faecalis, other Enterobacteriaceae, and yeast.^2-4 Some species are more common in certain subgroups, such as S saprophyticus among younger women.^2-4

Although UTIs can occur in anyone, medical conditions that can increase susceptibility to the infections include pregnancy, diabetes, urinary stones, the presence of urinary catheters, a history of recurring UTIs, and urinary obstructions such as those caused by an enlarged prostate.^2,3

Nonprescription Treatment

A number of OTC products provide relief from the pain associated with UTIs (Table 1).² Nonprescription products marketed as urinary analgesics contain the analgesic phenazopyridine hydrochloride, an azo dye that exerts a local anesthetic or analgesic effect on the mucosa of the urinary tract.⁵ The precise mechanism of action of phenazopyridine is unknown, but it is indicated for the symptomatic relief of urinary burning, itching, frequency, and urgency associated with UTIs.⁵

During counseling, patients should be advised that phenazopyridine does not treat a UTI, but acts only as an analgesic. They should be advised to consult their primary health care provider immediately for confirmation of diagnosis and proper treatment of the UTI. Common adverse effects associated with the use of phenazopyridine include headache, dizziness, and abdominal cramps. Patients should be advised to take 2 tablets after meals 3 times a day as needed with a full glass of water for no more than 2 days without consulting a physician.^5-7 No more than 12 tablets should be taken in a 48-hour period.^5-7

These analgesics can be used in conjunction with the antibiotics prescribed for the UTI, and patients should be encouraged to contact their primary health care provider if they experience pain or discomfort for longer than 2 days.^5-7 Phenazopyridine may cause an orange or red coloration of the urine and may also lead to staining of clothing.^5-7

Only 1 nonprescription product on the market contains the antibacterial agent methenamine and the analgesic sodium salicylate, but it should not be used as a replacement for antibiotic therapy.⁸ The recommended directions for use of the product are 2 tablets with a full glass of water 4 times per day.⁸ Patients with aspirin allergies, those with a history of gastric ulcers or bleeding disorders, those on anticoagulation therapy, and those with diabetes, gout, or arthritis should be sure to consult their primary physician before using this product.⁸

In addition to analgesics, several nutritional supplements containing cranberry can be used for preventive therapy.^9,10 Although cranberry’s exact mechanism of action is unknown, some research suggests that it may inhibit bacteria—particularly E coli—from adhering to the bladder, kidneys, and urethra.¹⁰ Cranberry products are marketed to assist in maintaining a healthy urinary tract by preventing bacteria from attaching to the bladder wall.^9,10

OTC Tests for Detecting UTIs

There are various UTI diagnostic tests available that can confirm the presence of a UTI by detecting nitrites and/or leukocytes in the urine (Table 2).² The primary reasons for using UTI test kits are for early detection in patients with a history of recurring UTIs or to confirm that a UTI has been cured after a complete course of antibiotics.² Tetracycline may produce a false negative reading for nitrites.² Women should be reminded not to use test strips during menstruation, because blood may cause a false positive result.² Patients should also be aware that doses in excess of 250 mg of vitamin C may result in a false negative result because ascorbic acid inhibits the nitrite test reaction.² Patients should be advised to wait at least 10 hours after ingesting vitamin C before testing.² If more than 500 mg of vitamin C is ingested within 24 hours of testing, false negative results may occur in leukocyte tests.²

Patients on a strict vegetarian diet may consume insufficient urinary nitrites, which in turn can cause false negative nitrite results in UTI tests.²

Although these tests detect approximately 90% of UTIs, patients should always contact their primary health care provider to confirm their status if they test negative but still experience signs and symptoms of a UTI.²

Counseling

During counseling, it is imperative that patients clearly understand that nonprescription urinary tract analgesics are not intended to treat UTIs and that they must consult their primary health care provider for antibiotic treatment of the UTI. Patients electing to use analgesics should be counseled on their recommended dosage and duration of use as well as potential adverse effects.

Patients using test kits to detect UTIs should be reminded to immediately consult their primary care provider if they get a positive test result or if they continue to experience urinary discomfort or other common UTI symptoms despite a negative test result. Patients who have never had a UTI or those experiencing severe symptoms should always be referred for further medical evaluation to confirm and properly treat the UTI.

Female patients susceptible to UTIs may also benefit from nonpharmacologic measures that can help prevent or decrease the incidence of UTIs, such as maintaining adequate hydration, voiding when needed, not resisting the urge to urinate, and always wiping from front to back after urination to prevent bacteria from entering the vagina or urethra.¹¹

Excellent patient education resources regarding UTIs can be found on the National Kidney Foundation website at www.kidney.org/atoz/pdf/uti.pdf.

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.

References

1. About urinary tract infections. Azo product website. www.azoproducts.com/uti/about. Accessed April 3, 2012.

2. Briggs G, Hurley H. Home testing and monitoring devices. In: Krinsky D, Berardi R, Ferreri S, et al, eds. Handbook of Nonprescription Drugs. 17th ed. Washington, DC: American Pharmacists Association; 2012.

3. Brusch JL. Cystitis in females. Medscape website. http://emedicine.medscape.com/article/233101-overview#a0101. Accessed April 6, 2012.

4. Urinary tract infections. Merck Manual for Healthcare Professionals Online Edition. www.merckmanuals.com/professional/genitourinary_disorders/urinary_tract_infections_uti/bacterial_urinary_tract_infections.html. Accessed April 5, 2012.

5. Phenazopyridine drug information. Medscape website. http://reference.medscape.com/drug/azo-standard-pyridium-phenazopyridine-343349. Accessed April 5, 2012.

6. Uricalm pain medicine product information. Alva-Amco website. www.alva-amco.com/components/com_alva/documents/skus/drug-facts/uricalm-drug-facts.pdf/. Accessed April 5, 2012.

7. Azo standard product information. i-Health.Inc website. www.azoproducts.com/products/azo_standard_max. Accessed April 5, 2012.

8. Cystex product information website. www.cystex.com/Pages/About%20Cystex. Accessed April 5, 2012.

9. Azo cranberry supplement product information website. www.azoproducts.com/faq/azo_cranberry. Accessed April 4, 2012.

10. McQueen C, Orr K. Natural products. In: Krinsky D, Berardi R, Ferreri S, et al, eds. Handbook of Nonprescription Drugs. 17th ed. Washington, DC: American Pharmacists Association; 2012.

11. Urinary tract infections in adults. National Kidney and Urologic Diseases Information Clearinghouse website. http://kidney.niddk.nih.gov/kudiseases/pubs/utiadult/#prevention. Accessed April 5, 2012.