Some children showing up in emergency rooms with overdoses of cough or cold syrup may have been intentionally medicated to keep them quiet, doctors cautioned on Thursday.

An analysis of 189 children who died from medication overdoses showed a significant percentage appeared to have been intentionally overdosed, the doctors reported in the Annals of Emergency Medicine.

"This is a heads up," said Dr. Richard Dart, director of the Rocky Mountain Poison and Drug Center in Denver.

In 79 of the cases, an adult gave the child nonprescription medicine. In 19 cases the adults clearly meant to help the child, but in 26 cases a panel of experts determined the intent was not to treat, Dart said.

He said a panel of experts had to agree that the intent was clear. "They were quite certain in all the cases they decided were intentional," Dart said in a telephone interview.

"We had some cases where the parent poured it into the kid's mouth directly from the bottle," he added.

In October, U.S. makers of over-the-counter cough and cold medications, urged by the U.S. Food and Drug Administration, advised that these drugs should not be used in children under 4 and the FDA is considering requests to ban their use in children under 12.

Dart said complications from accidental misuse are known and dangerous.

"We aren't trying to say there aren't accidents. I am concerned that we have blinders on and we don't want to admit that there is a group of parents who all the warnings in the world won't help because they did it knowingly," he said.

"What we have is a group of adults who want to control the behavior of children and do it in a variety of ways," Dart added.

"Sometimes it is physical violence and sometimes it is drugs. They tend to be lower-income, under-educated parents, often with a history of child abuse or violence in the home. I think there is a clear population here for us to focus on that are involved in these events."

Parents should also be aware that some of the adults who gave the medications to the children were day-care providers who probably were not malevolent in their actions but simply overwhelmed and looking for a way to quiet down their charges, Dart said.

An estimated 4 million children under the age of 12 are treated with over-the-counter cough and cold products each week in the United States.