CANADIANS WARNED OF ADHD DRUGS' PSYCHOLOGICAL RISKS

Health Canada is revising the prescribing and patient information for attention-deficit/hyperactivity disorder (ADHD) drugs to include data about the potential risk for adverse psychiatric events, including rare instances of agitation and hallucinations in children.

This revision coincides with continuing reviews of the psychiatric side effects of these drugs. According to the FDA, many patients had hallucinations involving insects, snakes or worms after taking ADHD medication.

In March, the agency announced it would follow a recommendation from its Pediatric Advisory Committee to add warnings about psychiatric events to ADHD drug labeling, but stopped short of calling for a black box warning.

Recently, GlaxoSmithKline (GSK) added new warnings to their labeling for ADHD medications. The company amended the prescribing information for Dexedrine (dextroamphetamine sulfate) to include warnings of psychotic risks including psychosis, mania and aggression in children. Their revision followed a request for additional warning language the FDA sent to all manufacturers of central-nervous-system stimulant products approved for the treatment of ADHD, GSK said.

The drugs have also been linked to an increased risk for cardiovascular events in patients with pre-existing heart conditions. These events include hypertension, chest pain, arrhythmia and tachycardia. The new GSK labeling also warns of the risk of sudden death in patients with heart abnormalities. Prior to the new psychiatric-related warnings, Canadians were told in May 2006 not to take ADHD medication if they have high blood pressure, heart disease or abnormalities, hardening of the arteries or an overactive thyroid gland.