Sildenafil Studied in Women With Antidepressant-Associated Sexual Dysfunction
"Efficacy and safety of sildenafil treatment in pulmonary arterial hypertension: a systematic review". Archived from the original on 29 August 2021.
Key takeaways:
Teva Canada launched Novo-Sildenafil, a generic version of Viagra, on the day the Supreme Court of Canada released its decision. [109][110][111] To remain competitive, Pfizer then reduced the price of Viagra in Canada. [112] However, on 9 November 2012, Pfizer filed a motion for a re-hearing of the appeal in the Supreme Court of Canada,[113] on the grounds that the court accidentally exceeded its jurisdiction by voiding the patent. [114] Finally, on 22 April 2013, the Supreme Court of Canada invalidated Pfizer's patent altogether. Manufacture and sale of sildenafil citrate drugs is common in China, where Pfizer's patent claim is not widely enforced.
Altitude sickness
Egypt approved Viagra for sale in 2002, but soon afterwards allowed local companies to produce generic versions of the drug, citing the interests of poor people who would not be able to afford Pfizer's price. In June 2013 Pfizer's patent on sildenafil citrate expired in some member countries of the European Union, including Austria, Denmark, France, Germany, Ireland, Italy, The Netherlands, Spain, Sweden, the United Kingdom, and Switzerland. [117][118][119] A UK patent held by Pfizer on the use of PDE5 inhibitors (see below) as treatment of impotence was invalidated in 2000 because of obviousness; this decision was upheld on appeal in 2002. Manufacture and sale of sildenafil citrate drugs known as "generic Viagra" is common in India, where Pfizer's patent claim does not apply. Brand names include Kamagra (Ajanta Pharma), Silagra (Cipla), Edegra (Sun Pharmaceutical), Penegra (Zydus Cadila), Manly (Cooper Pharma) and Zenegra (Alkem Laboratories).
What is FSAD?
Sildenafil was reclassified in New Zealand in 2014 so it could be bought over the counter from a pharmacist. It is thought that this reduced sales over the Internet and was safer as males could be referred for medical advice if appropriate. In 1999 South Korea granted two patents to Pfizer related to sildenafil. The first document guaranteed sole production and sale of the substance until 2012, while the second gave Pfizer the exclusive use to treating erectile dysfunction with sildenafil until 2014. [123] In 2011 Hanmi Pharmaceutical and CJ CheilJedang launched a suit against the exclusive use patent. "Raynaud's phenomenon and digital ischaemia--pharmacologic approach and alternative treatment options". "Efficacy of Sildenafil on healthy humans in high‑altitude hypoxia at rest and during exercise: A meta‑analysis".
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Viagra Generic | 150mg | 10 Pills | 36.73€ 34.98€ | |
| Viagra Generic | 50mg | 20 Pills | 40.52€ 38.59€ | |
| Viagra Generic | 25mg | 270 + 8 Pills | 184.26€ 175.49€ | |
| Viagra Generic | 50mg | 30 + 4 Pills | 54.26€ 51.68€ | |
| Viagra Generic | 100mg | 90 + 6 Pills | 129.02€ 122.88€ | |
| Kamagra Oral Jelly | 100mg | 21 Sachets | 95.92€ 91.35€ | |
| Viagra Generic | 200mg | 10 Pills | 40.96€ 39.01€ | |
| Kamagra Oral Jelly | 100mg | 110 + 9 Sachets | 334.87€ 318.92€ | |
| Kamagra | 100mg | 32 Pills | 121.24€ 115.47€ | |
| Kamagra Oral Jelly | 100mg | 30 + 5 Sachets | 136.20€ 129.71€ | |
| Kamagra Soft Tabs | 100mg | 120 + 6 Pills | 311.78€ 296.93€ | |
| Viagra Generic | 50mg | 10 Pills | 26.87€ 25.59€ |
"Interventions for preventing high altitude illness: Part 1. Archived from the original on 10 June 2017.
| Study Name | Focus Area | Results Summary | Year | Notes |
|---|---|---|---|---|
| Women's Sildenafil Study I | Arousal and blood flow | Improved arousal scores | 2021 | Small sample size |
| Female ED Treatment Trials | Efficacy and safety | Favorable results, some side effects | 2022 | Larger scale studies ongoing |
| Off-label Sildenafil Use in Women | Safety profile | Generally safe, monitor side effects | 2023 | Regulatory approval pending |
| Clitoral Blood Flow Enhancement Study | Blood flow and sensitivity | Significant improvements | 2024 | Supporting further research |
^ "FDA Updates Labeling for Viagra, Cialis and Levitra for Rare Post-Marketing Reports of Eye Problems" (Press release).
- Sildenafil works by relaxing blood vessels, increasing blood flow to genital areas.
- Female sexual arousal disorder may potentially be treated with sildenafil.
- Research shows mixed results regarding sildenafil's effectiveness in women.
- Sildenafil is not approved by the FDA specifically for women’s sexual problems.
- Possible risks for women include headaches and low blood pressure.
- Always consult a healthcare provider before trying sildenafil for women.
Archived from the original on 22 October 2016. "Vision disorders and phosphodiesterase type 5 inhibitors: a review of the evidence to date".
- Awareness of sildenafil's potential side effects helps women make informed choices.
- Women should avoid using sildenafil with nitrates to prevent dangerous drops in blood pressure.
- Proper diagnosis of sexual dysfunction can guide appropriate treatment options.
- Scientific research continues to explore safer, women-specific sexual health drugs.
- Sildenafil’s long-term effects on women are not yet fully understood.
- Healthcare providers can help determine if sildenafil is appropriate for individual cases.
^ "FDA Announces sildenafil syrup Revisions to Labels for Cialis, Levitra and Viagra".
- Female sexual dysfunction affects millions worldwide, prompting research into treatments.
- Sildenafil is part of a broader conversation about women’s sexual health innovations.
- The role of sildenafil in improving orgasm quality is still being studied.
- It is essential to distinguish between clinical trial results and off-label use.
- Some women experience mood improvement alongside physical effects with sildenafil.
- Education about both benefits and risks is crucial for women considering sildenafil.
"Drug interactions with phosphodiesterase-5 inhibitors used for the treatment of erectile dysfunction or pulmonary hypertension". "Pharmacology and drug interaction effects of the phosphodiesterase 5 inhibitors: focus on alpha-blocker interactions". Use of sildenafil (Viagra) in patients with cardiovascular disease. American College of Cardiology/American Heart Association".
Key Words
"With Viagra Now Available Over-The-Counter In The U.K., Will The U.S. "Phosphodiesterase inhibitors for erectile dysfunction in patients with diabetes mellitus". "Strategies for managing sexual dysfunction induced by antidepressant medication". The Cochrane Database of Systematic Reviews (5) CD003382. Archived from the original on 10 October 2020. Journal of the American College of Cardiology. ^ "Viagra (Sildenafil Citrate): Side Effects, Interactions, Warning, Dosage & Uses". Archived from the original on 12 July 2018. "Young men add Viagra to their drug arsenal". Archived from the original on 4 September 2014.
Non-medical use
In 1994, Pfizer filed a patent covering the use of sildenafil to treat erectile dysfunction. [99] This would be marketed as Viagra. This patent was published in 2002 and expired in 2019. Teva sued to have the latter patent invalidated, but Pfizer prevailed in an August 2011 federal district court case. [100] An agreement with Pfizer allowed Teva to begin to provide the generic drug in December 2017.
Cite this article
In the United States, Pfizer received two patents for sildenafil: one for its indication to treat cardiovascular disease (marketed as Revatio) and another for its indication to treat erectile dysfunction (marketed as Viagra). The substance is the same under both brand names. Sildenafil is available as a generic drug in the United States, labeled for pulmonary arterial hypertension,[98] and to treat erectile dysfunction, as the patent expired in April 2020. In the US, Revatio and Viagra are marketed by Viatris after Upjohn was spun off from Pfizer. In Canada, Pfizer's patent 2,324,324 for Revatio (sildenafil used to treat pulmonary hypertension) was found invalid by the Federal Court in June 2010, on an application by Ratiopharm Inc.[106][107] On 8 November 2012, the Supreme Court of Canada ruled that Pfizer's patent 2,163,446 on Viagra was invalid from the beginning because the company did not provide full disclosure in its application.
Addyi (filbanserin)
The decision, Teva Canada Ltd. v. Pfizer Canada Inc., pointed to section 27(3)(b) of The Patent Act which requires that disclosure must include sufficient information "to enable any person skilled in the art or science to which it pertains" to produce it. It added further: "As a matter of policy and sound statutory interpretation, patentees cannot be allowed to 'game' the system in this way. This, in my view, is the key issue in this appeal. "Recreational use and misuse of phosphodiesterase 5 inhibitors".
| Use | Description | Typical Dosage | Notes |
|---|---|---|---|
| Female Sexual Arousal Disorder | Helps increase blood flow to enhance arousal | 25-50 mg | Prescribed by a doctor |
| Pulmonary Hypertension | Off-label use for specific pulmonary issues | 20 mg | Under medical supervision |
| Enhancing Clitoral Blood Flow | Used to improve clitoral responsiveness | Variable | Not FDA-approved for women |
| Treatment of Female Dyspareunia | Aims to reduce pain during intercourse | Experimental | Limited clinical trials |
Archived from the original on 21 August 2016. "Sildenafil does not improve sexual function in men without erectile dysfunction but does reduce the postorgasmic refractory time". ^ McCambridge J, Mitcheson L, Hunt N, Winstock A (March 2006). "The rise of Viagra among British illicit drug users: 5-year survey data".
Read next
The Korean Court system made a ruling against Pfizer in June 2012, allowing for the unhindered domestic production of generic prescription sildenafil. In 2012, Viagra lost its position as the top selling erectile dysfunction treatment in South Korea. This development was credited largely "due to the introduction of generic products." Generic sildenafil became publicly available in May. Sales of PalPal by Hanmi Pharmaceuticals totalled ₩22 billion or about 86% the market share of Viagra that year. [125] By 2017, there were over 50 generic sildenafil pills available.
Related medical questions
During that year Viagra sales slumped to 38% that of Palpal. There were 2,958,199 prescriptions for Sildenafil in 2016 in England, compared with 1,042,431 in 2006. In 2018, Viagra Connect, a particular formulation of Sildenafil marketed by Pfizer, became available for sale without a prescription in the UK. Archived from the original on 12 October 2020. ^ "Viagra 25mg film-coated tablets Summary of Product Characteristics (SmPC)".
Key takeaways
^ "Viagra Connect 50 mg film-coated tablets Summary of Product Characteristics (SmPC)". Archived from the original on 13 August 2020. Archived from the original on 11 October 2020. Archived from the original on 11 November 2020. ^ Nichols DJ, Muirhead GJ, Harness JA (6 March 2002). "Does marijuana use play a role in the recreational use of sildenafil?". Archived from the original on 26 January 2013. "Sildenafil accelerates reentrainment of circadian rhythms after advancing light schedules". Proceedings of the National Academy of Sciences of the United States of America. "Source: Roger Clemens, host of athletes pop Viagra to help onfield performance". Archived from the original on 14 August 2020. "Bears' Brandon Marshall says some NFL players use Viagra .. on the Field". Archived from the original on 5 March 2016.
Get on the List
"Pharmacokinetics of sildenafil after single oral doses in healthy male subjects: absolute bioavailability, food effects and dose proportionality". The American Society of Health-System Pharmacists. Archived sildenafil gel from the original on 23 April 2020. PDE-5 inhibitors appear to have significant but moderate efficacy in secondary [Raynaud's phenomenon]. "Sublingual sildenafil in the treatment of erectile dysfunction: faster onset of action with less dose".
Knowledge Gaps in Urologic Care of Female Spinal Cord Injury Patients
"The Serendipitous Story of Sildenafil: An Unexpected Oral Therapy for Erectile Dysfunction". ^ "Drug Approval Package: Viagra (sildenafil citrate) NDA #020895". U.S. Food and Drug Administration (FDA). Archived from the original on 31 March 2021.
Mohamed Alhefnawy1*, Abdulla Esawy2, Mohamed Abdelazeem1, Mohamed Elnamoury3, Ahmed Eissa4, Ahmed Zoair4, Ahmed Ghaith4, Ayman Hagras4 and Khaled Almekaty4
Archived from the original on 12 August 2025. ^ "Sildenafil Drug Usage Statistics, United States, 2014 - 2023". "Generic Viagra: Two versions of sildenafil hit the market today". Archived from the original on 25 November 2018. Archived from the original on 12 February 2022. "Towards a decade of detecting new analogues of sildenafil, tadalafil and vardenafil in food supplements: a history, analytical aspects and health risks". "Detection of sildenafil analogues in herbal products for erectile dysfunction". Archived from the original on 4 March 2016. ^ "FDA Warns Consumers About Dangerous Ingredients in "Dietary Supplements" Promoted for Sexual Enhancement". Archived from the original on 18 January 2017. ^ "Hidden Risks of Erectile Dysfunction 'Treatments' Sold Online". Archived from the original on 23 April 2019.
| Tip | Explanation | Rationale |
|---|---|---|
| Take on an empty stomach | Food, especially high-fat meals, delays absorption | Ensures faster effect |
| Follow prescribed dosage | Avoid overdose and side effects | Ensures safety and effectiveness |
| Do not mix with nitrates | Risk of severe hypotension | Critical safety warning |
| Monitor for side effects | Report persistent issues to healthcare provider | Ensures prompt management |
| Use with sexual stimulation | Enhances the effectiveness | Maximizes potential benefits |
^ R. Baselt, Disposition of Toxic Drugs and Chemicals in Man, 9th edition, Biomedical Publications, Seal Beach, CA, 2011, pp. Archived from the original (PDF) on 10 September 2011. "Structure of the catalytic domain of human phosphodiesterase 5 with bound drug molecules".
- Some women seek sildenafil for increasing genital blood flow and sensation.
- The placebo effect can influence perceived benefits in women using sildenafil.
- Women with cardiovascular risk should avoid sildenafil unless approved by a doctor.
- Topical or alternative therapies might be considered alongside or instead of sildenafil.
- Scientific consensus on sildenafil’s safety for women remains under development.
- Proper dosing and medical oversight are key to minimizing risks.
^ a b Webb DJ, Freestone S, Allen MJ, Muirhead GJ (March 1999). "Sildenafil citrate and blood-pressure-lowering drugs: results of drug interaction studies with an organic nitrate and a calcium antagonist".