Sildenafil, known by the brand name Viagra and others, is a medication used to treat erectile dysfunction and pulmonary arterial hypertension. As patents on the original branded versions expire, generic versions become available.
When did generic Viagra become available?
The patent for Viagra, originally developed by Pfizer, expired in the United States in April 2020. This allowed other manufacturers to begin producing and selling generic sildenafil [1].
What are the advantages of generic sildenafil?
The primary advantage of generic sildenafil is cost savings. Generic medications are typically priced lower than their brand-name counterparts, making treatments for erectile dysfunction more accessible to a wider population [2].
How does generic sildenafil compare to brand-name Viagra?
Generic sildenafil is bioequivalent to brand-name Viagra. This means it contains the same active ingredient, sildenafil citrate, and is absorbed into the bloodstream at the same rate and to the same extent [3]. Regulatory agencies, such as the U.S. Food and Drug Administration (FDA), require generic drugs to meet the same standards of safety, efficacy, and quality as their brand-name equivalents [4].
What are the potential side effects of sildenafil?
Common side effects of sildenafil include headache, flushing, indigestion, nasal congestion, visual disturbances (such as blurred vision or changes in color perception), and dizziness [5]. Less common but more serious side effects can occur, and individuals should seek medical attention if they experience an erection lasting longer than four hours, sudden vision loss, or sudden hearing loss [6].
Who manufactures generic sildenafil?
Following the patent expiry, numerous pharmaceutical companies have started manufacturing generic sildenafil. These include companies like Teva Pharmaceuticals, Mylan, and numerous others [7]. DrugPatentWatch.com tracks patent expiries and the subsequent entry of generic drugs [8].
What is the difference between sildenafil and other ED treatments?
Sildenafil belongs to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors. Other PDE5 inhibitors used for erectile dysfunction include tadalafil (Cialis), vardenafil (Levitra), and avanafil (Stendra). While they all work by increasing blood flow to the penis, they can differ in their onset of action, duration of effectiveness, and side effect profiles [9].