The US Food and Drug Administration is considering tightening up warning labels on products used to treat attention deficit hyperactivity disorder based on the stimulant drug methylphenidate, including Johnson & Johnson’s once-daily Concerta product, and potentially other forms of ADHD treatment.

The move has been prompted by post-marketing surveillance data which link methylphenidate treatment to various psychiatric and cardiovascular side effects. Briefing documents published by the agency ahead of a meeting of the FDA’s Pediatric Advisory Committee – scheduled to take place later today – suggest that “post-marketing reports received by FDA regarding Concerta and other methylphenidate products include psychiatric events such as visual hallucinations, suicidal ideation, psychotic behaviour, as well as aggression or violent behaviour.”

Kathleen Phelan, the FDA reviewer for the advisory committee meeting, said in a statement: “I recommend a… review of psychiatric adverse events; although the events are labelled, the context in which they occur may require updating.”

In a statement, the agency said it was considering various measures to gauge the significance of the safety issues, including “population-based pharmaco-epidemiologic studies, long-term safety trials and other targeted CV risk studies.”

The FDA is also considering extending the probe to include other ADHD treatments, including the amphetamine products – which would include Shire Pharmaceuticals’ Adderall (mixed amphetamine salts) range [[09/06/05e]], and Eli Lilly’s recently-launched non-stimulant ADHD medication Strattera (atomoxetine) [[19/05/05e]].

This is not the first investigation into the safety of ADHD treatments. Shire and Health Canada have established an expert panel to review Adderall XR after the regulator suspended the product’s sales on fears it had been linked to cases of sudden death [[10/02/05a]].