SAN DIEGO -- Ritalin and other stimulant drugs for attention deficit hyperactivity disorder work wonders for children who are unable to focus normally.

These medications have been used for decades.

Now, reports are coming in of serious adverse reactions, including sudden death or cardiovascular problems.

Is this something you should be concerned about?

"I like to draw. I like (to) play with cars. I like Bingo," said 7-year-old Savannah LePage.

These are activities LePage couldn't do a year ago. It was impossible for her to concentrate.

"She just couldn't grasp sitting there for 10 minutes and doing something," said Kristie LePage, Savannah's mother.

LePage has ADHD -- a condition where children can't focus.

But her life has turned around since she began taking a drug called Concerta.

"She gets almost 100 percent on every test she takes," said Kristie.

ADHD drugs have impacted the lives of millions of children, but now there are some new concerns.

Recently, the Food and Drug Administration advisory panel recommended Ritalin and other drugs should have a black box warning to say they may be linked to an increased risk of death or injury.

"We do know these medicines do affect the cardiovascular system," said University of California, San Diego psychiatrist Dr. David Feifel.

Feifel said medications like Ritalin and similar stimulants used to treat ADHD can increase heart rate and may increase blood pressure, but for decades millions of children have taken these drugs without adverse effects.

"To date there is no compelling evidence that this has any adverse effect on the cardiovascular system and certainly no evidence that it increases the rate of death," said Feifel.

The FDA found fewer than one reported death or life-threatening injury for every one million prescriptions filled.

"I think it is important for people to realize that these medications have been around since the 30s," said Feifel.

Savannah's mother said she is aware of the risks.

"Her life has improved so much that I certainly wouldn't change anything," said Kristie.

LePage said ADHD medication has made her life easier. She enjoys puzzles and other games that require concentration and patience.

"The medicine helped me, and so now I am getting (better) at it," said Lepage.

An FDA pediatric advisory panel has now rejected having black box warnings on the heart risks associated with ADHD drugs.

Doctors agree these adverse events certainly need further investigation.

For parents concerned about these rare side effects, doctors say they should consider the risks and benefits of ADHD medications.