On Friday lawyers said that AstraZeneca PLC had misinformed both patients and doctors with regards to the risk entailed by the use of the schizophrenia drug Seroquel.

Moreover, attorneys stated that AstraZeneca had been aware of the risks associated with its drug, as documents that were recently unsealed in a United States federal court case suggested.

The widely used schizophrenia drug Seroquel puts patients at the risk of weight gain and diabetes and according to the lawyers, AstraZeneca had known about them ever since 2000.

Ed Blizzard, an attorney at Blizzard, McCarthy & Nabers in Houston, stated during a conference call that besides having failed to notify patients and physicians about the risk of using Seroquel, the company had also marketed the drug as one that did not entail any risks.

The Blizzard, McCarthy & Nabers firm is representing patients who claim they have developed diabetes as a result of having used Seroquel, which is part of a family of drugs known as atypical antipsychotics.

The attorneys stated that internal e-mails and other documents proved that AstraZeneca officials had known about the connection between the drug and weight gain, yet they had used promotions saying Seroquel had no effect on weight or could even cause weight loss.

Seroquel is AstraZeneca's second-biggest selling drug, its sales for 2008 having amounted to $4.5 billion.

In their turn, AstraZeneca officials said that the company had conducted extensive studies concerning the drug and had offered all the relevant information to the Food and Drug Administration (FDA), company spokesman Tony Jewell revealed.