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Generic Didrex Availability

Didrex is a brand name of benzphetamine, approved by the FDA in the following formulation(s):

DIDREX (benzphetamine hydrochloride - tablet;oral)

  • Manufacturer: PHARMACIA AND UPJOHN
    Approved Prior to Jan 1, 1982
    Strength(s): 50MG [RLD] [AA]

Has a generic version of Didrex been approved?

Yes. The following products are equivalent to Didrex:

benzphetamine hydrochloride tablet;oral

  • Manufacturer: EMCURE PHARMS LTD
    Approval date: January 27, 2012
    Strength(s): 50MG [AA]
  • Manufacturer: IMPAX LABS
    Approval date: November 18, 2008
    Strength(s): 50MG [AA]
  • Manufacturer: KVK TECH
    Approval date: July 20, 2010
    Strength(s): 50MG [AA]
  • Manufacturer: MALLINCKRODT INC
    Approval date: April 25, 2007
    Strength(s): 50MG [AA]
  • Manufacturer: MIKART
    Approval date: September 15, 2010
    Strength(s): 50MG [AA]
  • Manufacturer: PADDOCK
    Approval date: April 17, 2006
    Strength(s): 50MG [AA]
  • Manufacturer: TEDOR PHARM
    Approval date: March 30, 2007
    Strength(s): 50MG [AA]

Note: Fraudulent online pharmacies may attempt to sell an illegal generic version of Didrex. These medications may be counterfeit and potentially unsafe. If you purchase medications online, be sure you are buying from a reputable and valid online pharmacy. Ask your health care provider for advice if you are unsure about the online purchase of any medication.

See also: About generic drugs.

Related Patents

There are no current U.S. patents associated with Didrex.


Drug PatentA drug patent is assigned by the U.S. Patent and Trademark Office and assigns exclusive legal right to the patent holder to protect the proprietary chemical formulation. The patent assigns exclusive legal right to the inventor or patent holder, and may include entities such as the drug brand name, trademark, product dosage form, ingredient formulation, or manufacturing process A patent usually expires 20 years from the date of filing, but can be variable based on many factors, including development of new formulations of the original chemical, and patent infringement litigation.
Drug ExclusivityExclusivity is the sole marketing rights granted by the FDA to a manufacturer upon the approval of a drug and may run simultaneously with a patent. Exclusivity periods can run from 180 days to seven years depending upon the circumstance of the exclusivity grant.
RLDA Reference Listed Drug (RLD) is an approved drug product to which new generic versions are compared to show that they are bioequivalent. A drug company seeking approval to market a generic equivalent must refer to the Reference Listed Drug in its Abbreviated New Drug Application (ANDA). By designating a single reference listed drug as the standard to which all generic versions must be shown to be bioequivalent, FDA hopes to avoid possible significant variations among generic drugs and their brand name counterpart.
AAProducts in conventional dosage forms not presenting bioequivalence problems. Products coded as AA contain active ingredients and dosage forms that are not regarded as presenting either actual or potential bioequivalence problems or drug quality or standards issues. However, all oral dosage forms must, nonetheless, meet an appropriate in vitro bioequivalence standard that is acceptable to the Agency in order to be approved.