By Lisa Rapaport

(Reuters Health) – Many people in the U.S. take antibiotics that weren’t prescribed for them, according to a new study that highlights one factor that may be contributing to the rise of antibiotic resistant infections.

A growing number of germs around the world are already resistant to antibiotics, making it increasingly difficult to treat infections that were once easy to combat with medications. While much of this problem is caused by doctors prescribing antibiotics to patients who don’t need them, people who use these drugs without seeing a doctor first are also part of the problem.

For the current study, researchers examined data from 31 previously published studies to assess nonprescription antibiotic use in the U.S. and the factors that may contribute to it.

One in four people had already used antibiotics without a prescription or intended to, the analysis found.

Up to almost half of people had stored antibiotics for future use or intended to do so, saving medicines prescribed for them or perhaps for a child, parent, or other family member, the study also found.

“Our findings show that people obtain antibiotics without a prescription in the U.S. from flea markets, health food stores, friends or relatives, pet stores or online,” said Dr. Larissa Grigoryan, lead author of the study and a researcher at Baylor College of Medicine in Houston.

“These results matter, because unlike most drugs that affect only an individual patient if used incorrectly, misuse of antibiotics can harm others by increasing risk of antimicrobial resistance, a growing global health threat,” Grigoryan said by email.

When people take antibiotics without a prescription, they often take unnecessary medication or choose an inappropriate drug or dose, the study team notes in the Annals of Internal Medicine. People might get sicker when they self-medicate with a drug that’s not effective for their illness, exposing themselves to potentially preventable complications – and they can also make antibiotics less effective not just for their own use but for others who need these drugs.

Every time somebody takes antibiotics they don’t need, it contributes to antibiotic resistance, according to the U.S. Centers for Disease Control and Prevention.

A big part of this problem is doctors prescribing antibiotics for viral infections like the common cold or flu, most sore throats, bronchitis, and many sinus and ear infections. Viruses don’t respond to antibiotics, and use of the drugs for viral infections helps bacteria to morph into superbugs that resist treatment in the future.

In the current study, people were more likely to take antibiotics without a prescription when they lacked health insurance, didn’t have access to a regular doctor or clinic, couldn’t afford the cost of doctor visits or drugs, couldn’t miss work to see a doctor, or were embarrassed to seek care for sexually transmitted infections.

Across all of the smaller studies, the proportion of people who said they had already used antibiotics without a prescription ranged from 1% to 66%.

“It seems at least partially influenced by the difficulty, inconvenience, and expense of getting appointments, which likely differ by patient population,” said Dr. Jeffrey Gerber of the University of Pennsylvania School of Medicine and the Children’s Hospital of Philadelphia.

“The overarching driver, however, is likely the fact that most people view antibiotics as generally harmless medicines that effectively treat colds,” Gerber, who wasn’t involved in the study, said by email.

“It’s not safe to take an antibiotic without a prescription,” Gerber added. “Most infections – especially respiratory infections – don’t need antibiotics – and when they do, it’s important to have a doctor chose the right antibiotic (there are dozens of different types of antibiotics, most of which work very differently) at the right dose for the right amount of time to maximize the chances of curing your infection while minimizing the chance that the antibiotic will cause you harm.”

SOURCE: Annals of Internal Medicine, online July 22, 2019.