Introduction to Sildenafil and Viagra

Sildenafil is the active ingredient in Viagra, a widely known medication used for the treatment of erectile dysfunction (ED). The drug works by increasing blood flow to the penis, allowing men to achieve and maintain an erection.

Pfizer and the expiration of the Viagra patent in June 2013

Pfizer held the patent for Viagra until June 2013.

After the patent expired, several pharmaceutical companies began manufacturing and marketing generic versions of the drug, containing the same active ingredient, sildenafil citrate.

Greenstone, a Pfizer subsidiary, and generic Viagra

Pfizer was the first company to introduce generic Viagra through its subsidiary, Greenstone. Greenstone's sildenafil citrate authorized generic is equivalent to the Viagra brand, ensuring the same quality and efficacy.

Major manufacturers of generic sildenafil:

Generic sildenafil is produced by various manufacturers worldwide, each with their own branded version. Some of the prominent manufacturers include:

• a. Accord
• b. Actavis
• c. Ajanta - Approved on October 12, 2018
• d. Aurobindo
• e. Bristol Labs
• f. Consilient
• g. Dr Reddy's

h. Mylan i. Pfizer j. Sandoz k. Teva - Launched their generic Viagra (sildenafil citrate) on December 11, 2017 l. Torrent m. Zentiva

Teva Pharmaceuticals and its role in sildenafil production

Teva Pharmaceutical Industries Ltd. is one of the major manufacturers of generic sildenafil. The company announced the exclusive launch of its generic Viagra (sildenafil citrate) on December 11, 2017.

Active ingredient: Sildenafil Citrate

All brands of sildenafil contain the same active ingredient, sildenafil citrate. This ingredient is responsible for the drug's intended effect, which is to treat erectile dysfunction.

Variations in inactive ingredients among manufacturers

While the active ingredient remains the same across all sildenafil brands, the inactive ingredients may differ. These variations, however, should not impact the overall effectiveness of the drug.

Pfizer's exclusivity in using the name 'Viagra'

Pfizer is the only company allowed to call its sildenafil product 'Viagra.' Other manufacturers must use their own branding or the generic name, sildenafil citrate.

Price competition among sildenafil manufacturers

With the expiration of Pfizer's patent and the introduction of various generic versions of sildenafil, price competition among manufacturers has intensified. The cost of sildenafil has decreased significantly since the patent expired, making the medication more accessible to a wider range of patients.

Customer preferences and assistance in choosing a brand

If you have a preference for a specific brand of sildenafil, customer service teams at pharmacies and healthcare providers can help you find the product that suits your needs.