Regulatory briefs: Allergic reactions warning on Merck & Co's Saphris; Eisai drops Pariet ER development

The US Food and Drug Administration is warning that serious allergic reactions have been reported with the use of drug giant Merck & Co’s (NYSE: MRK) antipsychotic Saphris (asenapine maleate), used to treat symptoms of schizophrenia and bipolar disorder, saying that the drug’s label has been revised to include information about this risk and to inform health care professionals that Saphris should not be used in patients with a known hypersensitivity to the drug.

From FDA approval in August 2009 to June 2011, around 235,000 prescriptions were dispensed for Saphris and about 87,000 patients received a dispensed prescription for Saphris from US out-patient retail pharmacies. The drug is licensed for sale outside the USA, China and Japan to Denmark’s Lundbeck, which markets it under the brand name Sycrest.

A search of the FDA's Adverse Event Reporting System (AERS) database identified 52 cases of Type I hypersensitivity reactions (allergic reactions) with Saphris use. Hypersensitivity reactions can be classified into four categories (Type I to Type IV). Signs and symptoms of Type I hypersensitivity reactions may include anaphylaxis (a life-threatening allergic reaction), angioedema (swelling of the deeper layers of the skin), low blood pressure, rapid heart rate, swollen tongue, difficulty breathing, wheezing, or rash. These signs and symptoms are consistent with the reactions reported in the 52 cases. Several cases reported multiple hypersensitivity reactions occurring at the same time, with some of these reactions occurring after the first dose of Saphris.