A US Food and Drug Administration panel will meet today to discuss whether the cardiovascular risk of commonly used attention-deficit hyperactivity disorder therapies should be studied by individual drug or by drug class.

The move follows reports of at least 51 sudden deaths from stroke, heart attacks and high blood pressure in US patients taking drugs to treat the disorder, which include UK-based Shire Pharmaceuticals’ Adderall (mixed amphetamine salts and Swiss drug giant Novartis’ Ritalin (methylphenidate).

Last June, the FDA announced an investigation into the safety of ADHD products based on the stimulant drug methylphenidate, including Johnson & Johnson's once-daily Concerta product, and said it was considering extending the review to include all ADHD treatments on the market. But the agency was subsequently advised to hold back on any label changes until it was established whether the reported side effects were common to all drugs in the class.

Use of ADHD drugs is still expanding rapidly in the USA, according to a report published last year by pharmacy benefits company Medco. Prescribing swelled 23% among young adults (aged 20-34), with a 40% in the amount spent on these prescriptions, while use older adults also climbed, up 33% in adults aged 39-49 and 36% in those aged 50-64.