A new study from the U.S. Centers for Disease Control and Prevention estimates 7,000 children aged 11 and younger visit hospital emergency departments each year because of cough and cold medications.

The study, published Monday by the journal Pediatrics, says approximately two-thirds of the visits were due to children taking the medication without a parent's supervision or knowledge.

CDC researchers reviewed 2004-2005 data from the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance project to describe visits due to the medications.

Ninety-three per cent of the children did not require hospital admission but a quarter of them did need additional treatment to eliminate the medicine from their bodies, researchers found.

Almost two-thirds of the children, 64 per cent, were aged two- to five-years-old, and nearly 80 per cent of this age group had taken the medication without supervision.

"Parents need to be vigilant about keeping these medicines out of their children's reach," said Dr. Denise Cardo, director of CDC's Division of Healthcare Quality Promotion.

"They should refrain from encouraging children to take medicine by telling the children that medication is candy."

Cardo also said adults should avoid taking adult medications in front of young children.

On Jan. 17, the U.S. Food and Drug Administration withdrew cough and cold medication for children less than two-years-old, warning that "serious and potentially life-threatening side-effects can occur."

The FDA is currently reviewing the safety of the products for children under 11.

In October, following warnings from the FDA, Health Canada warned consumers not to give over-the-counter cough and cold medications to children without first consulting a doctor.

Previous studies have questioned whether over-the-counter medications actually ease cold symptoms in children. Specialists recommend parents give sick children plenty of fluids and rest.