Millions of Americans each year visit their doctor for an outer ear infection known as swimmer’s ear. Don’t let the name fool you. Even landlubbers can get the infection, which is caused by bacteria that thrive in wet environments.

Quinolones have been prescribed liberally because they have widely been viewed as safe and effective. But scientists have now found some cause for concern.

University of Florida Health researchers say quinolone [KWI-nuh-lown] ear drops carry a small but significant risk of eardrum perforation, which can lead to hearing loss. The researchers analyzed data from tens of thousands of children and adults and found more than a twofold increased risk of a perforated eardrum among patients receiving quinolones. That’s compared with those receiving another common antibiotic ear drop containing neomycin [knee-uh-MY-sin].

The numbers are small — 38 people with perforated eardrums among 43,000 taking quinolones. But UF Health researchers say finding any risk is significant.

Neomycin also has its own hazards. Those include hearing loss after repeated use in the presence of a perforated ear drum or ear tube.

Quinolones have come under increased regulatory scrutiny in recent years because of their adverse effects on soft tissues and other issues when the drug is taken orally.

Researchers say physicians need to be more cautious when prescribing quinolones and might need to limit how they’re prescribed for patients. They note physicians might need to refrain from off-label uses, such as when the ear drops are prescribed for the removal of excessive ear wax.

Scientists aren’t saying people should stop using quinolones, just that doctors must be more cautious.