Mechanism of Action and Pharmacodynamics

Archived from the original on 10 March 2013.

Further information

Archived from the original on 9 January 2009. Archived from the original on 22 February 2021. ^ a b "Viagra now available over the counter without prescription in the UK". Archived from the original on 26 March 2021. Archived from the original on 8 December 2013.

How can I tell if Viagra’s not working?

"The coming generics threat to Pfizer's Viagra brand just got scarier". Archived from the original on 9 September 2017. ^ "Viagra to go generic in 2017 according to Pfizer agreement". Archived from the original on 1 sildenafil oral jelly 100 mg December 2017. "Sex, Drugs and That Little Blue Pill".

How can I get Viagra to work?

Archived from the original on 6 December 2017. "Why Pfizer Is About to Slash Viagra's Price in Half". Archived from the original on 7 December 2017. "Pfizer to lose patent of drug Viagra, Indian companies gear up with copycat versions: Pfizer's patent for the formulation of Viagra, used to treat impotence in men, ends in the US in 2020". Archived from the original on 17 April 2021. "Canadian Supreme court rules Viagra patent invalid". Archived from the original on 11 sildenafil 25 mg tablets November 2012. ^ "Viagra patent tossed out by Supreme Court: Decision allows generic versions of drug to be produced".

Brand Name	Manufacturer	Formulation Type	Typical Dosage	Notes
Viagra	Pfizer	Tablet	25, 50, 100 mg	Most well-known brand
Revatio	Pfizer	Tablet	20 mg	For pulmonary hypertension
Sildenafil Citrate	Various generic manufacturers	Tablet	25, 50, 100 mg	Generic versions available
Kamagra	Ajanta Pharma	Oral Gel	100 mg	Used off-label in some countries

Archived from the original on 18 September 2013. ^ "Pfizer Canada drops Viagra price after generic versions get Supreme Court green light".

Product	Dosage	Quantity + Bonus	Price
Kamagra Oral Jelly	100mg	110 + 9 Sachets	334.87€ 318.92€	Buy
Kamagra	100mg	360 + 6 Pills	839.95€ 799.95€	Buy
Kamagra Soft Tabs	100mg	60 + 4 Pills	180.59€ 171.99€	Buy
Viagra Generic	200mg	360 + 10 Pills	481.98€ 459.03€	Buy
Viagra Generic	100mg	20 Pills	45.58€ 43.41€	Buy
Kamagra Oral Jelly	100mg	30 + 5 Sachets	136.20€ 129.71€	Buy
Kamagra	100mg	84 + 6 Pills	264.44€ 251.85€	Buy
Viagra Generic	100mg	270 + 10 Pills	270.47€ 257.59€	Buy
Kamagra Polo	100mg	120 + 6 Pills	327.15€ 311.57€	Buy
Viagra Generic	25mg	180 + 6 Pills	154.93€ 147.55€	Buy

Archived from the original on 30 November 2012. Archived from the original on 27 December 2013.

Enhancing Healthcare Team Outcomes

^ "Set to conquer US, Indian 'Viagras' may give Pfizer a hard Time". Archived from the original on 22 December 2020. ^ a b "Pfizer Settles Viagra® Patent Litigation With Teva". "Lockout Supplements Issues Voluntary Nationwide Recall of Boner Bears Chocolate Syrup Due to Undeclared Sildenafil". Archived from the original on 19 November 2016.

What are the most common side effects of sildenafil?

"Counterfeit Viagra, Cialis, Levitra: The Ultimate Guide". Archived from the original on 10 January 2017. "Online pharmacies suspected of counterfeit drug sales". ^ "Erectile Dysfunction Medication the Most Seized Drug During Global Crackdown, Interpol Says". ^ "Global illicit medicines targeted by INTERPOL operation".

Most Recent Events

Archived from the original on 10 December 2023. ^ "Israeli-made AI exposes international fake Viagra network". ^ "Counterfeit Viagra Pills, Footwear, Belts, Car Emblems and Headphones Worth over $32 Million Seized at the LA/Long Beach Seaport U.S. Customs and Border Protection". Archived from the original on 12 October 2013. "In rare move, Pfizer asks Supreme Court to reconsider ruling that killed Viagra patent". Archived from the original on 5 February 2013. "The Supreme Court of Canada holds Pfizer's Viagra patent invalid".

Proper Use

Archived from the original on 10 June 2019. "Health situation in former communist bloc is dire, says Unicef". Archived from the original on 1 November 2012. ^ Gurevich M, Cormier N, Leedham U, Brown-Bowers A (August 2018). Sexuopharmaceutical use by men as prevention and proficiency".

Clinical Uses

"Spreading the Word, but What Word is That? Viagra and Male Sexuality in Popular Culture". "A new view of women's sexual problems: Why new? Archived from the original on 3 January 2009. Archived from the original on 12 October 2008.

Side effect details

"Sales of Impotence Drugs Fall, Defying Expectations". Archived from the original on 11 October 2007. ^ "Pfizer Courting More Controversy with Viagra 'Advergaming'". Archived from the original on 19 December 2019. Archived from the original on 6 May 2018. Archived from the original on 20 May 2013. ^ "Actavis Launches Generic Viagra in Europe as Patents Expire". Archived from the original on 29 October 2013. "What Will Happen When Viagra Goes Generic?". Archived from the original on 23 April 2011. ^ "Is Viagra about to lose its pulling power in the UK?". Archived from the original on 30 October 2013. Archived from the original on 22 August 2009.

Frequently asked questions

Retrieved 17 June 2024 – via Business Wire. Archived from the original on 17 June 2024. "Viagra patent expires in June, says Brazilian court". Archived from the original on 17 April 2012. ^ "Revatio patent ruled invalid for lack of sound prediction and obviousness". Archived from the original on 25 June 2007.

• Sildenafil can enhance the effects of other blood pressure medications.
• The drug’s safety profile is well-studied with many clinical trials.
• Cardiovascular health is an important consideration when taking sildenafil.
• Long-term use requires monitoring for adverse reactions.
• Patient education helps reduce risks and optimize dosage.
• Generic sildenafil offers a cost-effective alternative to branded Viagra.
• Regular health assessments can ensure safe usage.

"Viagra from the pharmacist: insight from reclassification in New Zealand". Archived from the original on 17 May 2021.

Country	Approval Status	Regulatory Agency	Notes
USA	Approved	FDA	For ED and pulmonary hypertension
European Union	Approved	EMA	Similar indications
India	Approved	CDSCO	Generic versions available
Australia	Approved	TGA	Prescription required

^ "Generic Viagra developers queue up, but may have to wait".

Potential Side Effects and Safety

Archived from the original on 3 March 2016. {{cite web}}: CS1 maint: deprecated archival service (link) ^ Teva Canada Ltd. v. Pfizer Canada Inc., 2012 SCC 60 at par. "Supreme Court ruling could lead to cheaper versions of Viagra". Archived from the original on 28 December 2021. ^ "Approved Viagra copies flood drugstores in Korea".

• Sildenafil citrate was first approved by the FDA in 1998.
• Its brand name is Viagra, but generic versions are available.
• The drug is available in tablets of various strengths, typically 25-100 mg.
• It can be prescribed for both men and in specific cases, women.
• Proper dosage varies based on health status and response.
• Use caution in patients with heart problems or low blood pressure.
• It is not a hormone or a testosterone booster.

^ "Viagra prescriptions almost triple in a decade".

What other drugs will affect sildenafil?

"Yes, There Is a Way to Get Generic Viagra". Archived from the original on 2 May 2016. "Pfizer Wins Viagra Patent Infringement Case Against Teva Pharmaceuticals". Archived from the original on 11 January 2015. ^ "Pfizer Completes Transaction to Combine Its Upjohn Business with Mylan". Archived from the original on 1 July 2024. ^ "MHRA reclassifies Viagra Connect tablets to a Pharmacy medicine". ^ "Viagra to be available without prescription in UK". SildenafilIn eliciting its mechanism of action, sildenafil ultimately prevents or minimizes the breakdown of cyclic guanosine monophosphate (cGMP) by inhibiting cGMP specific phosphodiesterase type 5 (PDE5) 11,12,13,14,15,16,8,9.

• Sildenafil is available in most countries through prescription only.
• It is used worldwide, with varying approval statuses.
• FDA and EMA have rigorous testing standards for sildenafil.
• Using the drug responsibly can lead to successful treatment outcomes.
• Combining sildenafil with other medications requires medical supervision.
• Be aware of the potential for drug interactions with heart or blood pressure meds.
• Always consult a healthcare professional for personalized advice.

The result of doing so allows cGMP present in both the penis and pulmonary vasculature to elicit smooth muscle relaxation and vasodilation that subsequently facilitates relief in pulmonary arterial hypertension and the increased flow of blood into the spongy erectile tissue of the penis that consequently allows it to grow in size and become erect and rigid 11,12,13,14,15,16,8,9.Interestingly enough, it is precisely via this mechanism why sildenafil was at first researched as a potential treatment for angina - or chest pain associated with inadequate blood flow to the heart - before being serendipitously indicated for treating erectile dysfunction in the late 1980s 7. Nevertheless, it is because of this mechanism that sildenafil is also indicated for treating pulmonary arterial hypertension but is also additionally notorious for interacting with various anti-anginal or anti-hypertensive agents to develop potentially rapid, excessive, and/or fatal hypotensive crises 4,5,6.Regardless, sildenafil, among a variety of other similar or related PDE5 inhibitors, has become a common and effective treatment for erectile dysfunction and since its formal approval for medical use in the public in 1998 7, continues to see millions of prescriptions written for it internationally. Although the medication has historically been most popularly recognized as Pfizer's brand name Viagra, sildenafil is currently available generically and even as a non-prescription over the counter medication in some countries 10.

Condition	Description	Recommended Dosage	Notes
Erectile Dysfunction (ED)	Difficulty achieving or maintaining an erection	50 mg before activity	Can be adjusted based on response
Pulmonary Arterial Hypertension	High blood pressure in lungs	20 mg three times daily	Prescribed under medical supervision
Off-label uses	Other potential uses	Varies	Use under healthcare provider guidance

In eliciting its mechanism of action, sildenafil ultimately prevents or minimizes the breakdown of cyclic guanosine monophosphate (cGMP) by inhibiting cGMP specific phosphodiesterase type 5 (PDE5) 11,12,13,14,15,16,8,9. The result of doing so allows cGMP present in both the penis and pulmonary vasculature to elicit smooth muscle relaxation and vasodilation that subsequently facilitates relief in pulmonary arterial hypertension and the increased flow of blood into the spongy erectile tissue of the penis that consequently allows it to grow in size and become erect and rigid 11,12,13,14,15,16,8,9. Interestingly enough, it is precisely via this mechanism why sildenafil was at first researched as a potential treatment for angina - or chest pain associated with inadequate blood flow to the heart - before being serendipitously indicated for treating erectile dysfunction in the late 1980s 7. Nevertheless, it is because of this mechanism that sildenafil is also indicated for treating pulmonary arterial hypertension but is also additionally notorious for interacting with various anti-anginal or anti-hypertensive agents to develop potentially rapid, excessive, and/or fatal hypotensive crises 4,5,6.

• The medication is classified as a controlled substance in some jurisdictions.
• Over-reliance on sildenafil without addressing underlying causes is discouraged.
• Psychological counseling may benefit some patients with ED.
• Detailed medical history helps determine if sildenafil is safe.
• Education on possible side effects improves patient safety.
• The drug does not cause dependency.
• Proper use ensures maximum therapeutic benefit and safety.

Regardless, sildenafil, among a variety of other similar or related PDE5 inhibitors, has become a common and effective treatment for erectile dysfunction and since its formal approval for medical use in the public in 1998 7, continues to see millions of prescriptions written for it internationally. Sildenafil is used to treat erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors.

What happens if I overdose?

^ Goldstein I, Lue TF, Padma-Nathan H, Rosen RC, Steers WD, Wicker PA (May 1998). "Oral sildenafil in the treatment of erectile dysfunction. Archived from the original on 14 January 2012. "Onset and duration of action of sildenafil for the treatment of erectile dysfunction". ^ "Scientist who developed Viagra receives knighthood in New Year's Honours".

Raynaud's phenomenon

Archived from the original on 14 January 2023. "Sildenafil: from angina to erectile dysfunction to pulmonary hypertension and beyond". Archived from the original on 26 September 2008. Our clinicians regularly offer patients the opportunity to take part in trials of new drugs and treatments. Morriston Hospital in Swansea, was the first in the world to trial Viagra!

Common Side Effects

^ Boolell M, Allen MJ, Ballard SA, Gepi-Attee S, Muirhead GJ, Naylor AM, et al. "Sildenafil: an orally active type 5 cyclic GMP-specific phosphodiesterase inhibitor for the treatment of penile erectile dysfunction". "Sildenafil (Viagra), a potent and selective inhibitor of Type 5 cGMP phosphodiesterase with utility for the treatment of male erectile dysfunction". "Drug repositioning: identifying and developing new uses for existing drugs". Archived from the original on 22 April 2019. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where this enzyme works. Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection.