50 Years of Urinary Tract Infections and Treatments

Has Much Changed?

Brandon Lajiness; Michelle J. Lajiness


Urol Nurs. 2019;39(5):235-239. 

In This Article

Overview of Antibiotics and UTI

The first antibiotic was derived from Fleming's 1928 discovery of antimicrobial properties held by the Penicillium mold, and its use to fight infection was made widespread in 1942 in the form of oral penicillin (Nickel, 2005). The problem with penicillin was its overuse and resistance to most gram-negative bacterium; the majority of UTIs are caused by the gram-negative E. coli, meaning penicillin could not be used to treat UTI effectively.

Another early breakthrough in antimicrobials was with the introduction of sulfanilamide in 1937. Sulfanilamide was effective for the treatment of acute and chronic cystitis, as well as pyelonephritis; however, the intolerable side effects (gastrointestinal distress, cyanosis, agranulocytosis) made its usefulness limited. It was not until the 1950s that an antimicrobial for UTI emerged in the form of nitrofurantoin, which is still used today as a first-line therapy. Nitrofurantoin was the first widely used antimicrobial treatment of UTI because it was very effective against E. coli, well-tolerated by patients, and safer than sulfanilamide. In the 1970s and 1980s, β-lactam antibiotics (e.g., amoxicillin, cephalexin) started becoming available. In 1972, trimethoprim was added to sulfamethoxazole to increase efficacy and decrease side effects (Chrichton & McDonnell, 1972). In the 1980s and 1990s, more fluoroquinolones were introduced, including norfloxacin, cipro floxa cin, ofloxacin, and levofloxacin, to try and combat the growing resistance to β-lactams, as well as emerging resistance to trimethoprim-sulfamethoxazole (Bactrim®). These agents had similar efficacy and side effect profiles.

During the 30-year period prior to the 1990s, several new antibiotics with different mechanisms of action and efficacy for different bacterial strains were introduced. Clinicians got accustomed to having different antibiotic treatments on the market. However, over the past decade, few new antibiotics have been developed due to cost and the time-consuming process for approval.

Current treatment of acute uncomplicated cystitis with antibiotics in the past 50 years has remained mostly unchanged. Use of several types of antibiotics for UTI are still in common use due to minimal resistances to them. These include nitrofurantoin, fosfomycin trometamol, fluoroquinolones (e.g., ofloxacin, ciprofloxacin, and levofloxacin), and β-lactam agents (e.g., cefdinir, cefaclor, and cefpodoxime-proxetil, but excluding amoxicillin and ampicillin). Fluoroquinolones have become more of a second-line treatment in the past 10 years due to resistance patterns and side-effect profiles (Brubaker et al., 2018).

Noted changes over the last 50 years are that the guidelines are now written specifically for diagnosis and treatment of UTI, and there are different contemporary classification systems of UTI. The most widely used guidelines, in addition to CAUTI guidelines developed by SUNA, are those developed by the Centers for Disease Control and Prevention (CDC), Infectious Diseases Society of America (IDSA), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), American Urogynecoloic Society (AUGS), American Urological Association (AUA), European Association of Urology (EAU), the Centers for Medicare and Medicaid Services (CMS), and the U.S. Food and Drug Admini stration (FDA). These can all be accessed online through the individual society websites.