Drugs (and drug costs) for urinary tract infections vary among specialties

A study also raised questions about whether current practices are increasing antibiotic resistance.

By Andis Robeznieks, amednews staff. Feb. 4, 2002.

The type of physician a woman sees to treat her urinary tract infection could make a difference of up to $69 for the cost of a 10-course drug treatment.

According to researchers in Illinois and California, "subspecialty cultures" may determine whether it costs $1.79, $20.34 or $70.98 (in 1999 prices) for a prescription received from a general practitioner, obstetrician-gynecologist or an internist.

In addition, Elbert S. Huang, MD, MPH, at the University of Chicago and Randall S. Stafford, MD, PhD, at Stanford University, Stanford, Calif., concluded that the drugs doctors prescribe for common infections also can affect patients' well-being and the growth of antibiotic resistance.

Their report, published Jan. 14 in the Archives of Internal Medicine, studied outcomes of 1,478 visits made by women between 18 and 75 years old from 1989 through 1998.

Despite recommendations published in 1993 and 1999 urging doctors to prescribe trimethoprim-sulfamethoxazole for treating UTIs, prescriptions for that antibiotic declined significantly during the period studied.

"We observed prescribing patterns that run counter to the recommendations of the Infectious Disease Society of America," stated Drs. Huang and Stafford in their report. "We are very concerned that antibiotic prescribing will diverge even further from formal recommendations as physicians begin to use new broad-spectrum fluoroquinolones, despite their overly broad coverage and increased costs."

Medicine to treat a UTI can cost less than $2 or more than $70.

In 1989-90, doctors prescribed trimethoprim-sulfamethoxazole about 48% of the time, the report stated. In 1997-98, however, this figure fell to 24%. At the same time, Drs. Huang and Stafford said fluoroquinolones increased from 19% of UTI prescriptions to 29%. Also, nitrofurantoin prescriptions jumped from 14% to 30%.

Dr. Huang credited the surprising increase in nitrofurantoin to the drug's lower side-effect profile and its popularity among ob-gyns.

"Interestingly, the obstetrics-gynecology literature does not recommend nitrofurantoin as the first-line antibiotic for UTI in pregnancy," the report stated, "but nitrofurantoin accounted for 46% of prescriptions among physicians in this specialty."

Dr. Huang noted that nitrofurantoin drugs are more widely advertised than forms of trimethoprim-sulfamethoxazole. The study also found internists to be heavy prescribers of fluoroquinolones, and that general practitioners and family physicians were reliable prescribers of trimethoprim-sulfamethoxazole.

According to the report, the Infectious Disease Society of America selected trimethoprim-sulfamethoxazole as standard UTI therapy because of concerns over cost and to slow the development of resistance to fluoroquinolone seen in other countries. But Dr. Huang said these recommendations were "buried" in a 1999 issue of Clinical Infectious Diseases and did not get widespread attention.

The report by Drs. Huang and Stafford did receive widespread attention in the mainstream media, but the news that physicians were not following guidelines or prescribing more expensive drugs was overlooked in favor of headlines that prescription patterns may be leading to antibiotic resistance.

"The first sentence of every report said: 'Doctors are increasing antibiotic resistance,' " Dr. Huang said. "Our study does raise the question of whether current practices are raising antibiotic resistance, but we don't exactly know yet if they are."

That said, Dr. Huang added that he would like doctors to think about resistance when prescribing antibiotics.

He also hopes this study stimulates further research.

"Many questions need to be looked at, such as what is happening to local patterns of [antibiotic] resistance, and there needs to be follow-up studies on why different specialties prescribe differently."