Determination That DIDREX (Benzphetamine Hydrochloride) Tablets, 25 Milligrams, Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness

AGENCY:

Food and Drug Administration, HHS.

ACTION:

Notice.

SUMMARY:

The Food and Drug Administration (FDA) has determined that DIDREX (benzphetamine hydrochloride (HCl)) Tablets, 25 milligrams (mg), were not withdrawn from sale for reasons of safety or effectiveness. This determination will allow FDA to approve abbreviated new drug applications (ANDAs) for benzphetamine HCl 25 mg tablets, if all other legal and regulatory requirements are met.

FOR FURTHER INFORMATION CONTACT:

Christine Bina, Center for Drug Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Ave., Bldg. 51, rm. 6220, Silver Spring, MD 20993-0002, 301-796-3601.

SUPPLEMENTARY INFORMATION:

In 1984, Congress enacted the Drug Price Competition and Patent Term Restoration Act of 1984 (Public Law 98-417) (the 1984 amendments), which authorized the approval of duplicate versions of drug products approved under an ANDA procedure. ANDA applicants must, with certain exceptions, show that the drug for which they are seeking approval contains the same active ingredient in the same strength and dosage form as the “listed drug,” which is a version of the drug that was previously approved. ANDA applicants do not have to repeat the extensive clinical testing otherwise necessary to gain approval of a new drug application (NDA). The only clinical data required in an ANDA are data to show that the drug that is the subject of the ANDA is bioequivalent to the listed drug.

The 1984 amendments include what is now section 505(j)(7) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 355(j)(7)), which requires FDA to publish a list of all approved drugs. FDA publishes this list as part of the “Approved Drug Products With Therapeutic Equivalence Evaluations,” which is generally known as the “Orange Book.” Under FDA regulations, drugs are withdrawn from the list if the agency withdraws or suspends approval of the drug's NDA or ANDA for reasons of safety or effectiveness or if FDA determines that the listed drug was withdrawn from sale for reasons of safety or effectiveness (21 CFR 314.162).

Under § 314.161(a)(1) (21 CFR 314.161(a)(1), the agency must determine whether a listed drug was withdrawn from sale for reasons of safety or effectiveness before an ANDA that refers to that listed drug may be approved. FDA may not approve an ANDA that does not refer to a listed drug.

DIDREX (benzphetamine HCl) Tablets, 25 mg, are the subject of approved NDA 12-427 held by Pharmacia and Upjohn Co., a subsidiary of Pfizer Inc. Benzphetamine HCl 25-mg tablets are indicated in the management of exogenous obesity as a short-term (a few weeks) adjunct in a regimen of weight reduction based on caloric restriction. NDA 12-427 was initially approved in 1960. In 1973, under the Drug Efficacy Study Implementation, FDA concluded that benzphetamine HCl 25-mg tablets are effective for the indications described in the Federal Register document published on February 12, 1973 (38 FR 4280). Pfizer Inc. ceased manufacturing DIDREX (benzphetamine HCL) Tablets, 25 mg, prior to September 1992. FDA received a citizen petition from Lachman Consultant Services, Inc., dated January 2, 2008, submitted under 21 CFR 10.30. The petition requests that the agency determine whether DIDREX (benzphetamine HCL) Tablets, 25 mg, were withdrawn from sale for reasons of safety or effectiveness.

FDA has reviewed its records and under § 314.161, has determined that DIDREX (benzphetamine HCL) Tablets, 25 mg, were not withdrawn from sale for reasons of safety or effectiveness. The petitioner has identified no data or other information suggesting that DIDREX (benzphetamine HCL) Tablets, 25 mg were withdrawn from sale as a result of safety or effectiveness concerns. FDA's independent evaluation of relevant information has uncovered no information that would indicate this product was withdrawn for reasons of safety or effectiveness. In addition, DIDREX (benzphetamine HCL) Tablets currently are being marketed in a 50-mg scored tablet. The lower, 25-mg strength of DIDREX (benzphetamine HCL) Tablets is within the effective dosing range (25 to 50 mg, 1 to 3 times daily) and currently can be obtained by breaking in half the scored 50-mg strength tablet.

After considering the citizen petition and reviewing agency records, FDA determines that for the reasons outlined previously, DIDREX (benzphetamine HCL) Tablets, 25 mg, were not withdrawn from sale for reasons of safety or effectiveness. Accordingly, the agency will continue to list DIDREX (benzphetamine HCl) Tablets, 25 mg, in the “Discontinued Drug Product List” section of the Orange Book. The “Discontinued Drug Product List” delineates, among other items, drug products that have been discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to DIDREX (benzphetamine HCl) Tablets, 25 mg, may be approved by the agency as long as they meet all relevant legal and regulatory requirements for the approval of ANDAs. If FDA determines that the labeling of this drug product should be revised to meet current standards, the agency will advise ANDA applicants to submit such labeling.