Even after warnings from doctors and drug regulators about the dangers of opioids for children, 1 in 20 kids still get codeine after two common childhood surgeries, a U.S. study suggests.

Researchers examined records for almost 363,000 children who had tonsillectomies and adenoidectomies from 2010 to 2015. The U.S. Food and Drug Administration (FDA) issued a black box warning against use of codeine in kids because of the risk of overdoses and deaths.

Following the FDA warning, codeine prescribing related to these two surgeries decreased significantly, by roughly 13 percentage points. But by the end of 2015, nearly three years after the black box warning, about 5 percent of kids were still getting codeine prescriptions after these procedures.

“This is an unacceptable gamble, given that there are better alternatives,” said lead study author Dr. Kao-Ping Chua, pediatrician at the University of Michigan C.S. Mott Children’s Hospital.

Many kids don’t have severe pain after getting their tonsils out and can manage any discomfort with medicines like ibuprofen or acetaminophen, Chua said. If they need something stronger, alternatives to codeine include Oxycodone and hydrocodone.

“Codeine prescribing in children for any reason should be a zero event,” Chua said by email.

Last year, the American Academy of Pediatrics recommended against any use of codeine for children.

Codeine used to be one of the most commonly prescribed painkillers for kids after tonsillectomy and adenoidectomy in part because it was perceived as safer than higher potency opioids like hydrocodone and Oxycodone, researchers noted online November 16 in Pediatrics.

But between 1969 and 2012, the FDA received 13 reports of kids who died or overdosed after taking codeine, including eight who had recently undergone these surgeries.

Many of these overdoses happened in kids with genetic differences that made their bodies rapidly convert codeine into morphine in the liver, leading to dangerously high levels of morphine in the blood that could cause suppression of breathing or even death.

For the study, researchers examined health insurance records for kids up to 18-years-old who had private coverage to see how often they got at least one prescription for codeine or other opioids within seven days of surgery. They also looked at how often prescriptions were filled.

At the start of the study, about 31 percent of the kids filled at least one prescription for codeine within 7 days of surgery — and about 32 percent of kids got at least one prescription filled for an alternative opioid.

As of January 2010, codeine products made up 47 percent of prescriptions filled, while the rest were hydrocodone and Oxycodone. By the end of the study period, codeine accounted for just 9 percent of prescriptions and the majority were for hydrocodone.

The study wasn’t a controlled experiment designed to prove whether or how shifts in recommendations about codeine influenced prescriptions after surgery. It’s also possible that results for kids with private health insurance might not represent what happened for children with other types of benefits or no insurance.

Still, the results suggest that pediatric codeine prescriptions persist in spite of the risks, said Dr. Constance Houck, a researcher at Boston Children’s Hospital and Harvard Medical School, who wasn’t involved in the study.

“Parents should know that there are other medications to treat pain such as acetaminophen, ibuprofen or numbing medications,” Houck said by email.

“If an opioid is prescribed, it should be one that does not have to be broken down in the body in order to provide pain relief,” Houck added. “Oxycodone and hydrocodone are two pain medicines that are available in liquid form that can be used instead of codeine.”