Bacteria Behind 75% of Urinary Tract Infections Is Resistant to Drugs

Escherichia coli (E. coli) bacteria's resistance to ciprofloxacin (Cipro), the most widely prescribed anti-microbial for urinary tract infections in the United States, increased fivefold between 2000 and 2010, according to a recent study.

E. coli accounts for 75% to 95% of urinary tract infections, which are among the most common infections in humans. Half of all women experience at least one urinary tract infection in their lifetime.

E. coli antimicrobial resistance reduces the likelihood of clinical cure, increases the risk of infection recurrence and increases treatment costs and hospitalization rates.

The surveillance study of more than 12 million bacteria also found that nearly one-fourth of E. coli in 2010 were resistant to trimethoprim sulfamethoxazole (brand name Bactrim), the second most commonly prescribed drug for urinary tract infections.

The study was published in the journal Antimicrobial Agents and Chemotherapy.

"Our study is important because it shows that E. coli resistance to two common drugs to treat [urinary tract infections rose substantially over the last decade," said lead study author and researcher Guillermo Sanchez, physician assistant program, George Washington University in Washington, DC.

What This Means For Patients

"For patients, this will ultimately translate into more expensive and sometimes more complex antimicrobial treatments," Sanchez said. "What is more concerning, however, is the lack of new antimicrobial drug development, which has been declining for decades."

There are other antimicrobial drugs available to treat urinary tract infections, but they are more likely to cause side effects such as gastrointestinal problems, nausea and vomiting.

"Our study reveals that ciprofloxacin and [trimethoprim-sulfamethoxazole) are no longer safe for outpatient urinary tract infection," said Jose Bordon, MD, PhD, an infectious disease specialist at Providence Hospital in Washington, DC. "Our study indicates that safer antimicrobials for outpatient [urinary tract infection] are nitrofurantoin in patients without kidney insufficiency and amoxicillin clavulanate and third-generation cephalosporins for all others."

Is It Safe to Take a "Drug Break”?

Drug holidays—going off medications for a period of time for various reasons, such as assessing side effects-should not be done without the consent of your physician. The dosage of some drugs, including selective serotonin reuptake inhibitor antidepressants, such as paroxetine (Paxil) and fluoxetine (Prozac), needs to be gradually decreased, since withdrawal symptoms can occur if you abruptly stop taking them. Also, drugs that treat chronic conditions, such as asthma or high blood pressure, need to be continuously taken to be effective. A pharmacist can also advise you on how best to discontinue or taper off some prescription and OTC medications. If you feel that you are taking too many drugs, you need to discuss how best to reduce or eliminate them with your physician.