About one in 10 children south of the border take cough and cold medications in any given week, new data shows.

In January, the U.S. Food and Drug Administration issued a warning that children under two not take cough and cold medications and recommended that kids under six not take them as well. The warning came after thousands of adverse reactions to the drugs in young children were reported, which led to hospitalizations and in some cases deaths.

Health Canada issued an advisory to parents last fall, urging them to consult a doctor before giving their children cough and cold drugs.

"Given concerns about potential harmful effects and lack of evidence proving that these medications are effective in young children, the fact that one in ten U.S. children is using one of these medications is striking," said lead author Louis Vernacchio, an assistant professor of epidemiology and pediatrics at Boston University School of Medicine, in a release.

According to a study published in the August issue of Pediatrics, researchers at Boston University looked at data from between 1999 and 2006 collected through a national phone survey. The survey examined the use of cough and cold medication.

The survey found that 10.1 per cent of U.S. kids took at least one cough and cold drug during a given week. It also revealed that:

• Children's exposure was highest to decongestants (6.3 per cent of all drugs) and antihistamines (6.3 per cent)
• Kids' exposure to anti-cough ingredients was 4.1 per cent.
• Children's exposure to expectorants was 1.5 per cent.

Kids under two and those aged two to five were most exposed to cough and cold drugs, researchers found.

On a positive note, there was a slight decline in cough and cold drug usage, falling to 8.4 per cent in 2005 -2006, from 12.3 per cent in 1999-2000.