Generic Versions Of Premarin Rejected

The government rejected generic versions of the estrogen replacement Premarin - the nation’s most widely prescribed medicine - saying they fail to exactly replicate the brand product.

“For something to be generic, it has to be absolutely identical and deliver the same active ingredients as the original product,” Don McLearn, a Food and Drug Administration spokesman, said Monday. “They (the generics) haven’t been able to do that.”

Premarin treats women with menopausal symptoms, can help prevent the bone-crippling disease osteoporosis and may be effective in fighting heart disease and warding off Alzheimer’s disease.

Premarin is a complex drug derived from the urine of pregnant mares and has a number of different estrogens. However, just how these estrogens act together to make a successful drug like Premarin work is not completely understood.

The generic forms of Premarin use synthetic replacements for the mare urine. Since it’s not fully understood how Premarin works, the FDA is legally prohibited from approving a generic drug that does not contain the exact active ingredients as the brand name, the agency said.