Over-the-counter cough and cold remedies can cause "serious and potentially life-threatening side-effects" in young children, drug experts warned last night.
America's Food and Drug Administration said the remedies should not be given to toddlers under the age of two because of safety fears.
The regulator, which provides safety information on medicines, said its warning followed reports of deaths, convulsions and rapid heart rates among children given overdoses. Dr Charles Ganley, director of the FDA's Office of Non-Prescription Products, said: "The FDA strongly recommends to parents and caregivers that OTC cough and cold medicines not be used for children younger than two.
"These medicines, which treat symptoms and not the underlying condition, have not been shown to be safe or effective in children under two."
The body representing UK drugs companies confirmed that some of the ingredients causing concern in America were found in best-selling British products - including some brands of Tixylix, Benylin and Calpol.
However, it stressed that none had been shown to be dangerous when used correctly and that parents could continue to use them with confidence if they followed the instructions closely.
Concerns have been growing in America about over-the-counter children's medicines. Last year, the American College of Chest Physicians said cough mixtures were of little use to adults and could harm children.
Source - Daily Mail