Federal regulators have asked the makers of a widely used class of six antipsychotic drugs to include labeling language about a possible link with diabetes, Eli Lilly & Co. said Wednesday.
Lilly’s antipsychotic Zyprexa is the company’s top selling drug, accounting for about one-third of the firm’s sales. It is also the category’s top seller.
The Food and Drug Administration’s request, made in a letter received this week by the drugs’ producers, follows several recent studies exploring a possible diabetes link. Label warnings already have been required for some of the drugs overseas.
FDA spokeswoman Susan Cruzan said the agency frequently makes requests for additional drug labeling. Cruzan added she was unaware of any enforcement steps the FDA might take in case a company does not comply, which she said rarely occurs.
“It is in their interest to put the information in the labeling,” Cruzan said.
The other drugs that fall under the FDA’s labeling request are: Bristol-Myers Squibb’s Abilify, Pfizer’s Geodon, Novartis’ Clozaril, Janssen’s Risperdal and AstraZeneca’s Seroquel.
The FDA letter recommends patients using the so-called atypical antipsychotics be monitored for blood-sugar abnormalities, particularly if they have risk factors including obesity and a family history of diabetes.
The letter said there is no clear link between the drugs and diabetes, but further study is needed. More label changes could be required depending on future findings.
Studies have shown a higher incidence of low blood-sugar and diabetes among schizophrenics regardless of whether they use antipsychotics when compared with the general population. The key question is whether the drugs aggravate the risk. Many of them carry the possible side effect of weight gain, and obesity is a risk factor in diabetes.
Lilly spokeswoman Marni Lemons said the company was in discussions with the FDA regarding the new labeling.
Bristol-Myers Squibb was “working quickly to respond to the FDA” regarding Abilify, company spokeswoman Tracy Furey said.
The FDA’s labeling request “levels the playing field among all atypical antipsychotics” in the debate about a possible diabetes link, said analyst Robert Hazlett of SunTrust Robinson Humphrey.
He predicted any impact on the drugs’ sales would be minor.
U.S. sales of the six leading antipsychotics totaled $5.4 billion in the 12-month period ended Aug. 31, with 22.7 million prescriptions written, according to NDCHealth, a health care research company. Zyprexa was the top seller, with nearly $2.4 billion in U.S. sales.
Zyprexa has come under pressure because of the emergence of newer rivals Geodon and Abilify.
Zyprexa has been singled out by some in the diabetes controversy because of its well-documented link to weight gain in some patients.
This year, Lilly also became the target of product-liability lawsuits that attempt to link Zyprexa with life-threatening and fatal cases of diabetes.