The FDA’s inquiry was prompted by an internal reexamination of previously submitted data for the three approved generic versions of Concerta, which included non-brand-name methylphenidate hydrochloride extended-release tablets manufactured by Mallinckrodt Pharmaceuticals, Kudco Ireland Ltd, and Concerta manufacturer Janssen Pharmaceuticals. The results showed that while Janssen’s generic version was therapeutically equivalent to brand-name Concerta—releasing medicine in the body over a period of 10 to 12 hours—the generic versions manufactured by Mallinckrodt and Kudco were more likely to deliver the medicines at a slower rate during the designated time range, which may lessen the drug’s desired effect in some patients.
As a result, the FDA changed the therapeutic equivalence (TE) rating for the Mallinckrodt and Kudco products from AB to BX—meaning that the products are still approved and can be prescribed, but are no longer recommended as automatic substitutes for Concerta at pharmacies. The FDA has asked Mallinckrodt and Kudco to confirm the bioequivalence of their products within six months or to voluntarily withdraw them from the market.
In a statement, the FDA said, “If you or your health care professional are concerned the drug product is not providing the desired effect and you do not know the manufacturer, contact the pharmacy where the prescription was filled to verify the product’s manufacturer.... [Also] contact the prescribing health care provider to discuss whether or not a different drug product would be more appropriate.” The FDA has not identified any serious safety concerns with the two generic products.
Read the FDA press release on generic versions of Concerta here.