The generic version of sildenafil is available, and it is also called sildenafil [1]. Sildenafil is used to treat erectile dysfunction and pulmonary arterial hypertension [2].
When did sildenafil go off-patent?
Pfizer's patent for Viagra, the brand-name version of sildenafil, expired in the United States in April 2020 [3]. This allowed generic manufacturers to begin producing and selling sildenafil [3].
Who makes generic sildenafil?
Several pharmaceutical companies manufacture and distribute generic sildenafil. These include Teva Pharmaceuticals, Mylan, and Aurobindo Pharma, among others [1].
How does generic sildenafil compare to Viagra?
Generic sildenafil is bioequivalent to 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 [4]. Consequently, generic sildenafil is expected to have the same effects, side effects, and safety profile as Viagra [4]. The primary difference is typically the inactive ingredients and the cost [4].
What are the uses of sildenafil?
Sildenafil is prescribed for two main conditions:
* Erectile Dysfunction (ED): In this use, sildenafil helps men achieve and maintain an erection sufficient for sexual intercourse [2].
* Pulmonary Arterial Hypertension (PAH): Sildenafil is also used to improve exercise ability in adults with PAH [2]. In this context, it is marketed under the brand name Revatio [2].
What are the potential side effects of sildenafil?
Common side effects of sildenafil include headache, flushing, nasal congestion, indigestion, and changes in vision such as blurred vision or increased sensitivity to light [2]. Less common but more serious side effects can occur, and individuals should seek medical attention if they experience priapism (a prolonged erection), sudden vision loss, or sudden hearing loss [2].
Can I buy sildenafil without a prescription?
No, sildenafil is a prescription medication. It should only be taken under the supervision of a healthcare professional after a thorough medical evaluation [1][2]. The drug's potential interactions with other medications and pre-existing health conditions necessitate a prescription [2].
How much does generic sildenafil cost?
The cost of generic sildenafil is typically lower than that of brand-name Viagra. Prices can vary significantly depending on the pharmacy, dosage, quantity, and insurance coverage [1]. It is advisable to compare prices at different pharmacies.
What are the risks associated with sildenafil?
Sildenafil is contraindicated in patients taking nitrate medications, as the combination can cause a dangerous drop in blood pressure [2]. It should also be used with caution by individuals with heart conditions, liver or kidney problems, or a history of stroke [2]. Sildenafil is not suitable for everyone, and a doctor's assessment is crucial [2].
What is the mechanism of action of sildenafil?
Sildenafil works by increasing blood flow to the penis [2]. It is a phosphodiesterase type 5 (PDE5) inhibitor. PDE5 is an enzyme that breaks down cyclic guanosine monophosphate (cGMP), a substance that causes smooth muscle relaxation and increased blood flow [5]. By inhibiting PDE5, sildenafil increases cGMP levels, leading to vasodilation and improved blood flow in the corpus cavernosum of the penis, which facilitates an erection in response to sexual stimulation [5]. For pulmonary arterial hypertension, it relaxes blood vessels in the lungs, reducing pressure [2].
Sources:
1. DrugPatentWatch.com
2. National Institutes of Health (NIH) - MedlinePlus
3. U.S. Food & Drug Administration (FDA)
4. U.S. Food & Drug Administration (FDA) - FDA.gov
5. National Library of Medicine (NLM) - PubMed