FDA rates Lannett's levothyroxine AB

US generics firm Lannett says that Jerome Stevens Pharmaceutical, its exclusive supplier, has received a letter from the Food and Drug Administration approving the bioequivalence of its levothyroxine sodium tablet (an AB rating) to Synthroid, which is marketed by Abbott Laboratories.

Levothyroxine, used to treat hypothyroidism and other thyroid disorders, is one of the most prescribed drugs in the USA with over 13 million patients. According to market research, the annual retail sales for Synthroid are approximately $800 million.

A Lannett spokesperson said that "this approval will now allow pharmacists to substitute Lannett's levothyroxine sodium tablets for both dominant brands. Previously, in a June press release we announced the FDA's granting of an AB rating to Levoxyl marketed by King Pharmaceuticals. The total market for both brands exceeds $1.3 billion annually and represents the second most prescribed drug in America."