US regulators have issued the strongest warning possible against treating children with cough syrup that contains opioid painkillers.
Makers of pain medicines that contain codeine and tramadol will now have to change the labels to ban users from giving them to children under 12 years old.
The new rules come after an investigation found a high risk of slowed breathing and death in young users.
Manufacturers will also have to urge limited use in older children and pregnant women.
The move comes amid a national push to control and investigate painkillers as America battles a burgeoning addiction epidemic.
Makers of pain medicines containing codeine and tramadol have been ordered by the FDA to make new labels banning under-12s from using their product
It did not come without warning.
In 2013, the agency warned against use of codeine and tramadol in children and adolescents to treat pain after surgery to remove tonsils.
Some of the products containing these drugs are only available by prescription, but some over-the-counter cough medicines contain codeine.
However, emerging research shows the risks are far higher than previously thought.
And a study last month revealed US Poison Control Centers receive an average of 32 calls a day from pediatric exposure to the narcotics.
The study, conducted by the Center for Injury Research and Policy and the Central Ohio Poison Center at Nationwide Children's Hospital, looked at figures from the National Poison Data System.
The centers receive phone calls through the Poison Help Line and record information about the product, route of exposure, individual exposed, exposure scenario and other data.
Researchers found that poison control centers received more than 188,000 calls to US Poison Control Centers for pediatric exposure to opioids from January 2000 through December 2015.
This averaged to 32 calls a day, or one every 45 minutes.
The medications leading to the most calls were hydrocodone, oxycodone, and codeine, all narcotic pain killers.