* Reviewers urge more study of weight gain, related issues
* Lilly, AstraZeneca drugs win new US approvals in kids
* Lilly says Zyprexa risks higher for youths than adults (Adds Zyprexa approvals in adolescents, company comments)
By Lisa Richwine
WASHINGTON, Dec 4 U.S. drug reviewers have urged regulators to take another look at the effects of newer antipsychotic medicines on children following reports of weight gain and other problems, a report released on Friday said.
Food and Drug Administration staff said a recent study of health insurance claims found children treated with the drugs "were much more likely to experience an adverse metabolic effect than adults, and the likelihood was directly correlated with age."
Metabolic effects can include abnormal weight gain, diabetes and increases in cholesterol, blood pressure and blood glucose.
"Although observational studies have limitations ... this provocative hypothesis should nonetheless be subject to some further evaluation by the agency," staff in the FDA's division of pharmacovigilance wrote in an Oct. 14 memo.
The memo was released as AstraZeneca (AZN.L) and Eli Lilly (LLY.N) announced FDA approval of their antipsychotics for younger patients. Astra's Seroquel was cleared for schizophrenia patients ages 13 to 17 and bipolar disorder patients ages 10 to 17, while Lilly's Zyprexa was approved for schizophrenia and bipolar disorder in ages 13 to 17.
The drugs are in class known as atypical antipsychotics, the newer family of antipsychotic medicines. Both classes of drugs block the action of dopamine in the brain, but the newer medicines act on other brain chemicals as well.
The atypical antispychotics are approved to treat schizophernia, bipolar disorder, depression and and other mental illnesses. The medicines also are increasingly prescribed to children for unapproved uses such as attention deficit hyperactivity disorder, or ADHD.
The FDA reviewed the drugs' use in children after a panel of outside advisers in November 2008 asked for more long-term data on the drugs' effects in youths. The agency will discuss its most recent findings at a public meeting of that panel on Tuesday.
The report released on Friday said an FDA analysis showed increased reporting of metabolic problems with Zyprexa and Seroquel. Those findings "by themselves may not reflect true agent-specific differences in risk," the agency staff added.
Reporting rates jumped for Zyprexa in 2006 and for Seroquel in 2007, the FDA staff said. Those spikes may be partly explained by cases submitted by law firms involved in suits against the companies, the reviewers said.
Zyprexa already carries a warning that it appears to carry increased metabolic risk over other atypical antipsychotics, and FDA staff said that may have stimulated more reports of problems with the drug.
Lilly spokesman Jamaison Schuler said the company has acknowledged greater risks for younger patients treated with Zyprexa.
"Clinicians should take into consideration the increased potential for weight gain and (elevated blood fats) in adolescents compared to adults, and the potential for long-term risks, which in many cases may lead them to consider prescribing other drugs first," Schuler said.
The FDA staff memo, written before Friday's approval of Seroquel for adolescents, recommended the Seroquel data undergo further review as was previously done for Zyprexa.
In a statement announcing Seroquel's approval for youths, AstraZeneca said the drug's warnings were updated to include information about weight gain and other issues seen in the studies of adolescents.
Zyprexa is Lilly's top-selling drug with sales of $4.7 billion last year. Seroquel is the second-best seller for AstraZeneca with 2008 sales of $4.5 billion.
The FDA review also included Bristol-Myers Squibb Co (BMY.N) and Otsuka Pharmaceutical Co's Abilify, Johnson & Johnson's (JNJ.N) Risperdal and Pfizer Inc's (PFE.N) Geodon.
Bristol-Myers and Otsuka monitor Abilify's safety, including metabolic effects, and "welcome discussion in medical and scientific forums to help ensure informed treatment decisions," Bristol-Myers spokeswoman Sonia Choi said.
Johnson & Johnson spokesman Srikant Ramaswami said the company had just received the FDA report and had not fully evaluated it.
A Pfizer spokeswoman did not immediately respond to a request for comment. (Reporting by Lisa Richwine; Editing by Steve Orlofsky, John Wallace and Carol Bishopric) ((Reuters Messaging: email@example.com; +1 202 310-5691)) ((Multimedia versions of Reuters Top News are now available for: * 3000 Xtra: visit topnews.session.rservices.com * BridgeStation: view story .134 For more information on Top News: topnews.reuters.com))