Levothyroxine Q&A

Information for Patients about Synthroid, Levoxyl, Unithroid and Levothroid

Why Didn't Synthroid Receive Approval for the "Generally Recognized as Safe and Effective" Citizen's Petition?

In late April of 2001, the FDA denied Synthroid's petition for GRAS/E status, and indicated that Synthroid would need to go throug the new drug application process. This denial came in the form of a nine-page letter in which the FDA justified the denial by citing a detailed list of safety and effectiveness problems with Synthroid.

Specifically, in denying the petition, the FDA wrote: "The history of potency failures...indicates that Synthroid has not been reliably potent and stable." The FDA also wrote to Synthroid's manufacturers, "Although you claim that Synthroid has been carefully manufactured, the violations of current good manufacturing practices discussed above indicate that Knoll has not always manufactured Synthroid in accordance with current standards for pharmaceutical manufacturing."

Will Synthroid be Approved by the August 14, 2001 Deadline?

The typical levothyroxine new drug application approval process takes nine to ten months. Since Abbott has not yet filed a new drug application for Synthroid, and has indicated that [link url=http://thyroid.about.com/library/weekly/aa043001a.htm]it intends to file[/link] no later than the August 14, 2001 deadline, it is highly unlikely that the application will be filed, and approval granted, before August 14, 2001.

Will the FDA Pull Synthroid Off the Market After August 14, 2001?

Abbott spokesman Dr. David Pizzuti says that Abbott believes that the act of applying before the August 14, 2001 will ensure that Synthroid remains available on the market with no interruption. While the initial Federal Register notice threatens "regulatory action" against any unapproved products being marketed after the deadline, in a letter to Knoll/Synthroid, dated April 26, 2001, the FDA makes it clear that they viewed the August 14, 2001 deadline is a firm one, saying:

"The FDA denies Knoll's request to set a date by which NDAs must be submitted rather than approved...We believe the additional year the Agency is allowing for all sponsors to obtain NDA approval grants in substantial part Knoll's request for additional time to comply with the 1997 notice.

(To read the full letter, download the Portable Document Format (PDF) version at the FDA website: [link url=http://www.fda.gov/ohrms/dockets/dailys/00/may00/050400/pav0001.pdf]http://www.fda.gov/oh rms/dockets/dailys/00/may00/050400/pav0001.pdf[/link])

Later verbal statements by the FDA have been more vague however, and this ambiguity leaves open the question of whether the deadline will be interpreted as applying to approval and not application, and whether an unapproved Synthroid product will be pulled off the market by the FDA in August until such time as FDA approval is granted.

In addition to the FDA's letter, the competitors of Synthroid who have already received FDA approval, as well The Gray Panthers, a consumer advocacy group, believe that the FDA means that approval must be granted by August 14, 2001 in order for Synthroid to legally remain on the market. Tim Fuller, Executive Director of the Gray Panthers, said in a press release in May, "The FDA clearly stated that a New Drug Application for Synthroid must be approved by August, not just submitted."