Can Amantadine be used for the flu?

Amantadine and the Flu: What You Need to Know

Amantadine, an antiviral medication, has been used in the past to treat and prevent influenza A virus infections, but its use is now limited due to a high rate of resistance from the circulating flu viruses [1].

Why are companies challenging this patent?

In the 1960s and 1970s, Amantadine was marketed as an antiviral medication for the treatment and prevention of influenza A virus infections. The medication was effective against various strains of the flu, including H2N2 and H3N2 viruses. However, over time, companies have discovered a high level of resistance to Amantadine in circulating flu viruses, making it less effective as an antiviral medication.

How does this drug compare with oseltamivir and zanamivir?

Today, more effective and well-tolerated antiviral medications such as oseltamivir (Tamiflu) and zanamivir (Relenza) are available for the treatment and prevention of influenza. These medications have been shown to be more effective in treating influenza A and B viruses, reducing the risk of hospitalization or death from flu complications.

What are the limitations of Amantadine?

The main limitations of Amantadine are its high rate of resistance from circulating flu viruses (above 90% in some cases) and its limited effectiveness against the influenza B virus. In addition, the effectiveness of Amantadine in treating influenza A virus infections also has limitations, as it may not be as effective in patients with a weakened immune system or those with severe cases of the flu [2].

When does exclusivity expire?

The patent for Amantadine expired several years ago, making it possible for generic versions to be produced and marketed. However, due to the high rate of resistance to the medication, its use has been largely discontinued except in specific cases, such as for the treatment of Parkinson's disease and drug-induced extrapyramidal reactions.

References:

[1] DrugPatentWatch.com. (2023). Amantadine (Symmetrel) patent information.

[2] World Health Organization. (2023). Antivirals for the treatment and prevention of influenza.

Note: As of the cut-off knowledge date in December 2023, DrugPatentWatch.com is used as a source of information. However, please note that patent information can change over time, and it is recommended to check current patent status for the most up-to-date information.