FRIDAY, June 17 (HealthDay News) -- Amid increased threats of drug-resistant infections, a new study reveals that doctors may overprescribe antibiotics to patients receiving ongoing medical care at home.

Researchers from McMaster University in Ontario, Canada, found that patients younger than 65 and those with poorer prognoses, in particular, are at greatest risk for misuse of the drugs.

"Taken together, our results reveal tremendous variability in how and why antibiotics are prescribed, and that overuse in the home-care population is likely," said one of the study's authors, Dr. Mark Loeb.

In conducting the study, published in the June issue of Infection Control and Hospital Epidemiology, researchers compiled medical information on more than 125,000 patients receiving home care for more than 60 days over the course of one year. The findings suggested that doctors may be more cautious with younger patients since those younger than 65 were more likely to receive a prescription for antibiotics.

They also found that patients with longer life expectancies were less likely to receive the drugs, even though they might benefit more from the treatment than other patients.

"Younger and sicker patients seem to be at added risk for misuse and should be the focus of further study to assess the appropriateness of antibiotic use at home," Loeb said in a journal news release.

The researchers noted that one of the most commonly prescribed classes of drugs was fluoroquinolones, which are often associated with increased rates of resistance. Since overuse could hinder their efficacy and lead to more drug-resistant infections, the study authors argued antibiotic use among home-care patients should be more closely tracked.

"Our results illustrate the importance of continuing to monitor antibiotic use in home-care patients, and the need for more effective methods of diagnosis that allow for appropriate antibiotic use," Loeb added.

More information

The U.S. Centers for Disease Control and Prevention provides more information on the proper use of antibiotics.