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Generic Relenza Availability

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

RELENZA (zanamivir - powder;inhalation)

Has a generic version of Relenza been approved?

No. There is currently no therapeutically equivalent version of Relenza available in the United States.

Note: Fraudulent online pharmacies may attempt to sell an illegal generic version of Relenza. 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

Patents are granted by the U.S. Patent and Trademark Office at any time during a drug's development and may include a wide range of claims.

  • Derivatives and analogues of 2-deoxy-2,3-didehydro-n-acetyl neuraminic acid and their use as antiviral agents
    Patent 5,648,379
    Issued: July 15, 1997
    Inventor(s): Von Itzstein; Laurence Mark & Wu; Wen-Yang & Van Phan; Tho & Danylec; Basil & Jin; Betty & Colman; Peter Malcolm & Varghese; Joseph Noozhumurry
    Assignee(s): Biota Scientific Management Pty., Ltd.
    Derivatives and analogues of 2-deoxy-2,3-didehydro-N-acetyl neuraminic acid, pharmaceutical formulations thereof, methods for their preparation and their use in the treatment of viral infections, in particular influenza, are described.
    Patent expiration dates:
    • July 15, 2014
    • July 15, 2014
    • July 15, 2014
  • Crystalline N-acetyl neuraminic acid derivatives and process for their preparation
    Patent 6,294,572
    Issued: September 25, 2001
    Inventor(s): Williamson; Christopher & White; William James & Patel; Vipulkumar
    Assignee(s): Biota Scientific Management Pty Ltd.
    Two useful crystal hydrates of 5-acetamido-2,3,4,5-tetradeoxy-4-guanidino-D-glycero-D-galacto-non-2-enopy ranosonic acid have either a low or high aspect ratio. These crystalline N-acetyl neurominic acid derivatives are favored for pharmaceutical formulation because of their physical properties. For example, the low aspect ratio crystal has good flow properties, and the high aspect ratio crystal has a stable water content over time.
    Patent expiration dates:
    • December 15, 2014
      Drug substance
      Drug product


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.