OTTAWA (Reuters) - Canada's health ministry on Friday warned people with high blood pressure, heart disease and a number of other medical ailments not to take drugs used to manage Attention Deficit Hyperactivity Disorder (ADHD).
Health Canada said that in rare cases, people with these conditions who took the drugs could suffer "rare heart-related side effects." In a statement, it warned people not to give up the drugs before consulting their doctor.
Millions take the drugs to treat attention deficit hyperactivity disorder, which causes trouble with focus as well as hyperactivity and impulsiveness.
"All ADHD drugs stimulate the heart and blood vessels ... The effects are usually mild or moderate, but in some patients this stimulation may -- in rare cases -- result in cardiac arrests, strokes or death," said Health Canada.
The drugs should be shunned by those with high blood pressure, heart disease or abnormalities, hardening of the arteries or those with an overactive thyroid gland, it added.
Reviewers at the U.S. Food and Drug Administration (FDA) have been working for months to analyze reports of sudden deaths, heart attacks and strokes as well as psychotic behavior such as hallucinations suffered by those who took the drugs.
In March, a panel of U.S. medical advisors called for new information about heart risks to be added to labeling for ADHD medications but stopped short of recommending tougher measures.
The drugs mentioned by Health Canada include:
* Adderall XR, made by Britain's Shire Pharmaceuticals Group Plc
* Concerta, made by Johnson & Johnson
* Ritalin and Ritalin SR, made by Novartis AG
* Dexedrine, made by GlaxoSmithKline Plc
* Strattera, made by Eli Lilly and Co.