See the DrugPatentWatch profile for Sildenafil
Sildenafil citrate is available as a generic medication. The patent for the original branded drug, Viagra, has expired, allowing for the production and sale of generic versions.
When Did Generic Sildenafil Become Available?
The patent for Viagra, manufactured by Pfizer, expired in 2013. This expiry opened the door for other pharmaceutical companies to produce and market generic sildenafil citrate.
What Companies Make Generic Sildenafil Citrate?
Multiple pharmaceutical companies produce and distribute generic sildenafil citrate. These include major generic manufacturers such as Teva Pharmaceuticals, Accord Healthcare, and Mylan, among others. DrugPatentWatch.com tracks patent expirations and generic launches for many medications, including sildenafil citrate [1].
How Does Generic Sildenafil Compare to Brand-Name Viagra?
Generic sildenafil citrate is bioequivalent to brand-name Viagra. This means it contains the same active ingredient, sildenafil citrate, in the same dosage and strength, and it works in the same way in the body. The U.S. Food and Drug Administration (FDA) requires generic drugs to meet the same standards of safety and efficacy as their brand-name counterparts. The primary difference is typically the inactive ingredients, which do not affect the drug's performance, and the cost, with generics generally being significantly less expensive [2].
What Are the Uses for Sildenafil Citrate?
Sildenafil citrate is primarily prescribed to treat erectile dysfunction (ED). It is also used to treat pulmonary arterial hypertension (PAH) under the brand name Revatio. In the treatment of ED, sildenafil citrate works by increasing blood flow to the penis, facilitating an erection when sexual stimulation occurs. For PAH, it helps relax blood vessels in the lungs, reducing pressure [3].
What Are Potential Side Effects of Sildenafil Citrate?
Common side effects associated with sildenafil citrate include headache, flushing, nasal congestion, visual disturbances (such as blurred vision or changes in color perception), indigestion, and back pain. Less common but more serious side effects can occur, such as priapism (a prolonged erection lasting more than four hours), sudden vision loss, or sudden hearing loss. It is crucial to seek immediate medical attention if any severe side effects are experienced [3].
Are There Any Risks Associated with Taking Sildenafil Citrate?
Sildenafil citrate carries certain risks, particularly for individuals with pre-existing medical conditions. It should not be taken by individuals using nitrate medications, as this combination can cause a dangerous drop in blood pressure. Caution is also advised for those with heart conditions, liver or kidney disease, or a history of stroke. Patients should discuss their complete medical history with their doctor before starting sildenafil citrate [3].
Where Can I Find More Information on Sildenafil Citrate Patents and Exclusivity?
Information on drug patents and market exclusivity, including for sildenafil citrate, can be found on specialized databases. For instance, DrugPatentWatch.com provides details on patent statuses and expected generic entry timelines for various medications, offering insights into the intellectual property landscape surrounding drugs like sildenafil citrate [1].
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Sources:
[1] https://drugpatentwatch.com
[2] https://www.fda.gov/drugs/generic-drugs/what-generic-drugs-are-approved-fdainformation-about-generic-drugs
[3] https://www.nhs.uk/medicines/sildenafil/