Giving children free prescription drug samples is a marketing tool that may be unsafe, according to a study published Monday.

In the journal Pediatrics, researchers analyzed the results of a 2004 survey by the U.S. Centers for Disease Control and Prevention.

'Free samples encourage the casual use of medications in our children before enough is known about potential harm.'— Lead author Dr. Sarah Cutrona

They found more than 500,000 children in the U.S. received samples of four medicines that the U.S. Food and Drug Administration later issues safety warnings for:

• Fluticasone/salmeterol sold as Advair, for asthma.
• Amphetamine/dextroamphetamine sold as Adderall; and atomoxetine sold as Strattera, both for attention deficit disorder.
• Pimecrolimus, sold as Elidel, for eczema.

"New medications are frequently released before their safety profile is fully understood, and samples tend to be newer medications," said the study's lead author, Dr. Sarah Cutrona, a physician at Cambridge Health Alliance and an instructor at Harvard medical school.

"Free samples encourage the casual use of medications in our children before enough is known about potential harm. As a mother of young children, I find that very concerning."

'Unappreciated risk'

The two medications for attention deficit disorder have high potential for abuse, but doctors, nurses, office staff, pharmaceutical representatives and occasionally even patients may have unsupervised access to sample closets, the researchers said.

The samples may lack child-safety seals, and could be given out without proper directions on how to take it, or warnings about side-effects and potential reactions, according to the study. The samples bypass the safety step offered by pharmacists, the study's authors noted.

"Previous findings in adults [a study on free samples in adults showed rofecoxib or Vioxx, which was pulled over cardiovascular concerns, was commonly given as a free sample] strongly suggest that free drug samples serve as a marketing tool," said the study's senior author, Dr. Neal LeLeiko, director of pediatric gastroenterology and nutrition at Hasbro Children's Hospital in Providence, R.I. , and a professor of pediatrics at Brown University.

"Our study shows that samples can pose a serious and unappreciated risk to our children."

Few samples to poor

Parents of more than 38,000 children under the age of two said they were given samples of the eczema medication, the researchers found. The FDA later received reports of skin cancer in patients taking the medication and its safety warning was boosted, along with a reminder that it is not approved for use in children under two.

The Pharmaceutical Research and Manufacturers of America, which represents the pharmaceutical industry, has said that free samples help uninsured, low-income people to get medicines.

But the researchers found few of the samples went to poor children, and more than 80 per cent of children receiving samples were insured all year.

"Poor and uninsured children are not the main recipients of free drug samples," the study concluded. "Free samples do not target the neediest children selectively."