Atypical antipsychotics cause significant weight gain in children and young adults, JAMA study reports

Antipsychotic drugs widely used in children and young adults caused weight gain of as much as 19 pounds on average after just 11 weeks on the medications, according to a new study published in the current issue of the Journal of the American Medical Association. The study results come as the US Food and Drug Administration is considering approving younger patients' use of a few of the drugs, which largely have been cleared only for adults. Atypical antipsychotics have limited approval for youths, doctors are free to prescribe them as they see fit and often give them to children and adolescents, say analysts and psychiatrists.

The findings reported by Christoph Correll, the study's lead author (a psychiatrist and a scientist at the Feinstein Institute for Medical Research in Manhasset, New York, USA), .and colleagues in JAMA, are both timely and sobering, the authors state. Prior treatment-naive youth (N=272), aged four to 19 years, gained substantial weight during a 12-week period of clinician's choice treatment with atypical antipsychotic medications. Significant abnormalities in lipid profiles and other metabolic parameters were also noted.

The study involved 272 children aged four years to 19 with bipolar disorder, schizophrenia or other behavioral disorders who were treated with Eli Lilly's Zyprexa (olanzapine), AstraZeneca's Seroquel (quetiapine), Bristol-Myers Squibb/Otsuka's Abilify (aripiprazole) or Johnson & Johnson's Risperdal (risperidone), as prescribed by their physicians.

Abilify and Risperdal are approved for treating children with schizophrenia and bipolar disorder. AstraZeneca is seeking clearance to market Seroquel for treating children, and Eli Lilly is asking for the same for Zyprexa. Eli Lilly and Johnson & Johnson said that their drug labels already reflect the potential for weight gain.

The mean weight gain across treatment groups ranged from 8.5 kg with olanzapine to 4.4 kg with aripiprazole. More than half gained more than 7% of their total body weight. Significant abnormalities in lipid profiles and other metabolic parameters were also noted, especially with olanzapine. Comparison patients had minimal changes in body weight and lipid levels over the same period. The weight gain is 'massive, and it's the medication that caused it,' said Dr Correll, and 'is much larger than we thought."

"The onset of the weight gain was so pronounced and so significant there's probably an argument for doing those measurements every few weeks," said Christopher Varley, a child psychiatrist at Seattle Children's Hospital, who wrote an editorial accompanying the study.

Impact in children

 Atypical antipsychotics were introduced for adults in the mid-1990s and marketed as having fewer neurological side effects than older drugs. The FDA has grappled with pediatric use for years because of concerns that weight gain, sleepiness and movement disorders reported as side effects in adults may be more pronounced in children, comments the Bloomberg news service.

US sales of antipsychotic drugs reached $14.6 billion last year, the most for any class of medicines, according to market research firm IMS Health. Use of antipsychotic medicines by people younger than 20 years old has more than doubled since 2001, according to data from Medco Health Solutions. Zyprexa is Lilly's top-selling drug with sales of $4.7 billion last year, while Seroquel is the second-best seller for AstraZeneca with 2008 turnover of $4.5 billion

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