Antibiotic resistance is an ongoing threat to health care's capacity to fight infections. Doctors who overprescribe those medications are one of the biggest causes. Now, researchers have identified a new culprit — in some cases, you might want to pin the blame on patients.

That's the somewhat surprising conclusion of a new study presented late last week at the American Academy of Pediatrics (AAP) conference and exhibition in Orlando, Fla.

In a survey sent anonymously to nearly 500 parents across the United States, parents were asked what they do with leftover antibiotics. Nearly half of the parents surveyed (48.2 per cent) said they'd kept leftover antibiotics rather than dispose of them.

The study's senior author Ruth Milanaik said results show an "alarming" percentage of parents sharing or borrowing antibiotics, a practice called prescription diversion.

"This is dangerous not only for those given antibiotics that weren't prescribed for them, but for entire populations of people who some antibiotics may no longer help when the bacteria they target become resistant to them," said Dr. Milanaik in the AAP media release.

Unused antibiotics given to others

Of those who kept leftover antibiotics, nearly three quarters (73 per cent) said they gave them to someone for whom the prescription was not intended.

The unused antibiotics ended up with a range of recipients. Most often the parents said they gave them to a sibling of the child for whom the antibiotic was intended.

In some cases, they gave the leftovers to the child of a friend. Occasionally, they gave the antibiotic to an adult not living in the family's household. Some parents took the antibiotic themselves.

In some cases, the antibiotic was given away months after it was originally prescribed. Just over 80 per cent of parents said they shared antibiotic suspensions or liquid antibiotics; more than 73 per cent said they shared antibiotic drops, nearly 70 per cent said they shared antibiotic creams, and 55.6 per cent said they shared antibiotic tablets.

There are several reasons why parents might be tempted to share antibiotics. One reason is the high cost of prescription drugs. Parents may be hoping to stretch out one prescription over two members of the family.

Another is the high cost of health care. The U.S. Centers for Disease Control and Prevention says 12.8 per cent of adults ages 18 to 64 are uninsured.

Parents who lack coverage may be tempted to diagnose and treat their children. Others may be insured but have to pay expensive co-pays every time they seek medical care for themselves or their children.

For single parents, it may be difficult for them to spare time away from work to take their children to the doctor.

Potential dangers

There are several potential harms to this sort of thing. When leftover antibiotics are given to someone else, there's a good chance that the dosage is incorrect.

Children typically receive liquid antibiotics at a dosage according to their weight. Unless the recipient has the same weight, the dosage will be too little or too much. Unlike the original prescription, there's no assurance that the leftover amount will be adequate to cover a full course of therapy.

If a parent intends to give some of the leftover antibiotics to another child, I'd be concerned that they might top up that amount by deliberately holding back some of the antibiotic intended for the child for whom it was prescribed.

Taking antibiotics at a lower than recommended dose, or for a shorter number of days than recommended, is a factor in the development of antibiotic resistance.

There are other concerns: 16 per cent of parents surveyed said they gave their child adult medications. That's a problem since some antibiotics given routinely to adults are contraindicated or not advisable in children.

Sometimes, the leftover antibiotic may cause a serious interaction with other medications the child is taking. When leftover antibiotics are given to a child not related to the parents, what duty is there to ask if the child has any drug allergies?

How to handle leftover antibiotics

So, how should parents handle leftover prescriptions? Pharmacies in Canada take back medications. In some parts of Canada, they organize days in which they encourage Canadians to return unused or leftover prescriptions. In the U.S., authorities recommend flushing unused medication down the toilet, but that practice is discouraged in Canada.

Experts discourage the ad hoc sharing of leftover antibiotics and other medications. Still, they like the idea of recycling antibiotics. Hospitals and long-term care facilities in the U.S. routinely donate leftover medications to clinics that serve uninsured Americans. Around 40 states have passed legislation that enables health-care facilities to do this. Sirum.org is a charitable organization in the U.S. that facilitates this.

Keep in mind that the Food and Drug Administration does not permit individuals to donate leftover medication.

Canada does not have a well-developed system for recycling medication as they have in the U.S.

I think it's something we should consider.

