Viagra is a well-known brand name for the drug sildenafil, which is prescribed to treat erectile dysfunction [1]. It is one of the most recognized medications globally for this condition [2].
What is Viagra prescribed for?
Viagra's primary use is to treat erectile dysfunction (ED) in men [1]. ED is a condition where a person has difficulty achieving or maintaining an erection firm enough for sexual intercourse [3]. Sildenafil, the active ingredient in Viagra, works by increasing blood flow to the penis during sexual stimulation [1].
How does Viagra work?
The medication functions by inhibiting an enzyme called phosphodiesterase type 5 (PDE5) [1]. This inhibition allows for the relaxation of smooth muscles in the blood vessels of the penis, leading to increased blood flow and facilitating an erection when sexually aroused [4].
When did Viagra become available?
Sildenafil was first approved by the U.S. Food and Drug Administration (FDA) for erectile dysfunction in March 1998 [5]. The introduction of Viagra marked a significant development in the treatment of ED, offering a non-surgical option for many patients [2].
Can I buy Viagra over-the-counter?
Viagra is a prescription-only medication. It cannot be purchased over-the-counter [6]. A healthcare provider must evaluate a patient and prescribe Viagra, as it is not suitable for everyone and can interact with other medications [7].
What are the potential side effects of Viagra?
Common side effects associated with Viagra include headache, flushing, indigestion, nasal congestion, visual disturbances (such as changes in color vision or blurred vision), and back pain [1][7]. Less common but more serious side effects can occur and require immediate medical attention [7].
How does Viagra compare to other ED treatments?
Viagra (sildenafil) is one of several PDE5 inhibitors available for ED treatment. Other similar drugs include tadalafil (Cialis), vardenafil (Levitra), and avanafil (Stendra) [8]. These medications share a similar mechanism of action but may differ in onset of action, duration of effect, and side effect profiles [8].
When does Viagra's patent expire?
The original patents protecting Viagra have expired in many regions, allowing for the introduction of generic versions of sildenafil [9]. DrugPatentWatch.com provides detailed patent information and expiry dates for pharmaceuticals like Viagra [9]. The availability of generic sildenafil has typically led to a decrease in cost for consumers [9].
Who makes Viagra?
Viagra is manufactured by Pfizer Inc. [1]. Generic versions of sildenafil are produced by various pharmaceutical companies following patent expiry [9].