Urinary Tract Infection: A Frequent Diagnosis

Knowing the symptoms of UTIs is imperative for helping affected patients.

Urinary tract infections (UTIs) are one of the most frequent diagnoses in the United States, accounting for 8 to 10 million doctor visits annually.¹ The direct health care costs associated with this infection have been documented to exceed $1 billion each year.²

Background

The urinary tract consists of a lower tract and an upper tract; most UTIs occur in the lower tract.³ These infections are further classified as uncomplicated or complicated, with the latter being associated with an underlying condition that increases the risk for therapeutic failure.⁴ For the purpose of this article, UTIs refer to acute, uncomplicated cystitis.

The urinary tract comprises the kidneys, ureters, bladder, and urethra, which work collaboratively to expel liquid waste from the body.³ Approximately one in 2 women will develop a UTI during their lifetime, with 20% of those experiencing a recurrence.⁵ With every UTI a woman experiences, the risk of recurrence increases.⁶

Women are more likely than men to acquire a UTI because of the distinct difference in their anatomical design. UTIs frequently result from bacteria ascending the urethra to the bladder or kidney, thereby initiating an infection. The female urethra is shorter than that the male urethra, thus allowing quicker access to the bladder. Furthermore, a woman’s urethral opening is positioned close to sources of bacteria: the anus and vagina.

Escherichia coli is responsible for most (75%-95%) UTIs, with the remaining causative microorganisms frequently including Proteus mirabilis, Klebsiella pneumonia, and Staphylococcus saprophyticus.⁷ Certain subgroups, such as younger women, are more commonly infected with S saprophyticus, however.⁸

Symptoms

The symptoms of a UTI may include the following³:

• Frequent need to urinate

• Burning sensation upon urination

• Intense pressure in the lower abdomen

• Pain in the lower back

• Blood in the urine

Pharmacists should be familiar with the symptoms of UTIs, as patients often seek medical assistance at their local pharmacies. This knowledge may assist in directing patients toward their health care provider for further assistance versus patients potentially misusing self-treatment.

Prevention

Several suggestions have been made to help prevent UTIs in women (Table 1⁹). Women should be encouraged to understand UTIs and assess themselves for the symptoms listed above. Cranberry products have been studied and controversially used in UTI prevention for several decades. These products are thought to inhibit the adhesion of uropathogens to the lining of the urinary tract, thus impairing colonization and subsequent infection.¹⁰

Treatment

Optimal treatment of UTIs is based on several factors and customized for each patient. Both OTC and prescription medications are used to treat UTIs. Each class of medication is important and should be appropriately administered.

OTC Medications

Phenazopyridine (Pyridium) is an OTC urinary analgesic that provides symptomatic relief of dysuria, itching, frequency, and urgency to urinate that are associated with UTIs. This azo dye exerts a local anesthetic (or analgesic effect) on the mucosa of the urinary tract through an unknown mechanism of action. Phenazopyridine may change the color of urine to orange or red, and common adverse effects (AEs) include headache, dizziness, and abdominal cramps. This medication is not advised to be given for more than 2 days without consulting a physician, as it can mask symptoms associated with antibiotic failure.¹¹

Prescription Medications

Recent guidelines have recommended 3 antibiotics available in the United States as first-line agents for UTI management (Table 2⁷). Although the traditional first-line agent for the treatment of UTIs was trimethoprim- sulfamethoxazole 160/800 mg (TMP-SMX, Bactrim DS), the rate of E coli resistance to the drug is increasingly becoming a problem across the United States.⁷ TMP-SMX is still recommended, however, when the local resistance rate of the uropathogen does not exceed 20% or if the infecting strain is known to be susceptible.⁷ TMP-SMX (160/800 mg) is administered twice daily for 3 days. During treatment with this medication, patients are urged to remain hydrated and use sunscreen.^7,12

Nitrofurantoin monohydrate/macrocrystals (Macrobid) is another first-line agent for the treatment of UTIs. Recent data suggest a 5-day regimen can be used rather than the traditional 7-day course. This agent is administered as 100 mg twice daily, and patients should be educated to take it with food and avoid antacids containing magnesium while on the therapy.^7,13

Fosfomycn tromethamine (Monurol) is also an appropriate choice for initial antibiotic therapy. The medication is associated with minimal resistance, and its single-dose regimen is an attractive feature for those who may have adherence issues. The medication is provided in a 3-g sachet that must be mixed with cold water and drunk immediately. Diarrhea is a common AE associated with this drug therapy, but should subside upon completion of therapy.^7,14

Fluoroquinolones are highly effective in the treatment of UTIs; however, because of the collateral damage associated with their use, they should be reserved for other important uses.

Beta lactams are considered generally inferior in efficacy and known to be associated with increased AEs.²

Role of the Pharmacist

Patients are likely to seek pharmacist advice regarding the symptoms, treatment, and prevention of UTIs. It is imperative that pharmacists educate patients on behaviors that may help minimize the risk of acquiring a UTI.¹⁵ Recommendations for various preventive agents may be provided, as well. Pharmacists should reinforce the value of each medication used in the treatment of UTIs. Patients who choose OTC medications for analgesic relief should be educated on their lack of antimicrobial activity. Patients receiving antibiotic therapy should receive regular counsel on the importance of completing the entire course of antibiotics, as well potential AEs associated with the medications.

Dr. Moore is an assistant professor at Howard University College of Pharmacy.

References

• Urinary tract infections in adults. National Kidney and Urologic Diseases Information Clearinghouse website. http://kidney.niddk.nih.gov/Kudiseases/pubs/utiadult/. Published November 2011. Updated May 24, 2012.Accessed on April 23, 2015.
• Gupta K, Hooton TM, Naber KG, et al; Infectious Diseases Society of America; European Society for Microbiology and Infectious Diseases. International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: a 2010 update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. Clin Infect Dis. 2011;52(5):e103-e120. doi: 10.1093/cid/ciq257.
• Urinary tract infection. University of Pittsburgh Medical Center website. www.upmc.com/patients-visitors/education/womens-health/Pages/urinary-tract-infection.aspx. Updated September 2011. Accessed April 23, 2015.
• Hooton TM. Acute complicated cystitis and pyelonephritis. UpToDate website. www.uptodate.com. Accessed May 1, 2015.
• Griebling TL. Urinary tract infection in women. In: Litwin MS, Saigal CS, eds. Urologic Diseases in America. Bethesda, MD: The National Institute of Diabetes and Digestive and Kidney Diseases; 2007:587-619.
• Schaeffer AJ. Infections of the urinary tract. In: Walsh PC, Retik AB, Vaughan ED, Wein AJ, eds. Campbell's Urology. 8th ed. Philadelphia, PA: Saunders; 2002: 515-602.
• Faro S, Fenner DE. Urinary tract infections. Clin Obstet Gynecol. 1998;41(3):744-754.
• Brusch JL. Cystitis in females. Medscape website. http://emedicine.medscape.com/article/233101-overview#showall. Updated April 7, 2014. Accessed April 23, 2015.
• Brusch JL. Prevention of urinary tract infections in women. Medscape website. http://emedicine.medscape.com/article/1958794-overview. Updated June 20, 2013. Accessed April 23, 2015.
• Guay DR. Cranbery and urinary tract infections. Drugs. 2009;69(7):775-807. doi: 10.2165/00003495-200969070-00002.
• Petri WA. Sulfonamides, trimethoprim-sulfamethoxazole, quinolones, and agents for urinary tract infections. In: Brunton LL, Lazo JS, Parker KL, eds. Goodman & Gilman's The Pharmacological Basis of Therapeutics. 11th edition. New York, NY: McGraw-Hill; 2005:1111.
• Bactrim. PDR Health website. www.pdrhealth.com/drugs/bactrim. Accessed April 25, 2015.
• Macrobid. PDR Health website. www.pdrhealth.com/drugs/macrobid. Accessed April 25, 2015.
• Monurol. PDR Health website. www.pdrhealth.com/drugs/monuol. Accessed April 25, 2015.
• Pellegrino AN. Preventing urinary tract infections. Pharmacy Times website. www.pharmacytimes.com/publications/issue/2009/2009-06/CounselingUTIs-0609. Accessed April 23, 2015.