WASHINGTON -- After receiving thousands of complaints from doctors and patients, U.S. regulators plan an extensive study of blood-pressure drugs that generate almost 40 million prescriptions a year.
Generics of AstraZeneca Plc's extended-release drug, Toprol XL, make up about 90 percent of physicians' orders for the medication. Copycat drugs are made by Wockhardt Ltd. and Dr. Reddy's Laboratories Ltd., both based in India, and Mylan Inc. and Actavis Plc in the United States.
Complaints against the drug -- known generically as metoprolol succinate -- cite both a lack of effectiveness and troublesome side effects, according to 3,425 adverse-incident reports Bloomberg News reported. While the reports generally don't identify manufacturers, the Food and Drug Administration tests will focus on whether the copies are chemically the same as the original, the funding request shows.
The plan to test metoprolol succinate expands on a $20 million FDA testing program begun in September. Over the past year, the agency has been ramping up effort to improve generic drugs' safety and quality, especially those from abroad.
Adverse incidents reported to the FDA, obtained under the Freedom of Information Act, span five years starting in March 2009. Such reports can come from companies, medical professionals and patients. While they are largely unverified by the agency, they sometimes are a first alert that U.S. regulators should look more closely at a product.
In this case, the FDA undertook initial tests that showed generic forms of the drug dissolved properly. The agency is now contracting with independent researchers to complete a more extensive study, spokeswoman Sandy Walsh said via email.. She said the FDA also has re-evaluated its criteria for approval of the generic products.
Wockhardt, India's seventh-largest drugmaker by revenue, controlled about 26 percent of the U.S. market for metoprolol succinate that it made in its Chikalthana plant, according to the investment bank Needham & Co. The facility was banned from sending drugs to the United States on Nov. 26, one of more than 20 Indian plants hit with U.S. bans since the start of last year. The FDA cited unsanitary conditions and workers who manipulated quality tests.