Sildenafil

"Viagra" redirects here. For other uses, see Viagra (disambiguation).

Sildenafil
Clinical data
Pronunciation/sɪlˈdɛnəfɪl/ sil-DEN-ə-fil
Trade namesViagra, others
AHFS/Drugs.comMonograph
MedlinePlusa699015
License data
Pregnancy
category
Routes of
administration		By mouth, sublingual, intravenous
Drug classPDE5 inhibitor
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability41% (mean)[7]
Protein binding~96%
MetabolismLiver: CYP3A4 (major route), CYP2C9 (minor route)
MetabolitesN-desmethylsildenafil (~50% potency for PDE5)
Onset of action20 minutes
Elimination half-life3–4 hours
ExcretionFeces (~80%), urine (~13%)[4]
Identifiers
  • 5-{2-Ethoxy-5-[(4-methylpiperazin-1-yl)sulfonyl]phenyl}-1-methyl-3-propyl-1,6-dihydro-6H-pyrazolo[4,3-d]pyrimidin-7-one
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
PDB ligand
CompTox Dashboard (EPA)
ECHA InfoCard100.122.676 Edit this at Wikidata
Chemical and physical data
FormulaC22H30N6O4S
Molar mass474.58 g·mol−1
3D model (JSmol)
  • CCCC1=NN(C2=C1N=C(NC2=O)C3=C(C=CC(=C3)S(=O)(=O)N4CCN(CC4)C)OCC)C
  • InChI=1S/C22H30N6O4S/c1-5-7-17-19-20(27(4)25-17)22(29)24-21(23-19)16-14-15(8-9-18(16)32-6-2)33(30,31)28-12-10-26(3)11-13-28/h8-9,14H,5-7,10-13H2,1-4H3,(H,23,24,29) ☒N
  • Key:BNRNXUUZRGQAQC-UHFFFAOYSA-N ☒N
 ☒NcheckY (what is this?)  (verify)

Sildenafil, sold under the brand name Viagra among others, is a medication used to treat erectile dysfunction and pulmonary arterial hypertension.[4][8] It is also sometimes used off-label for the treatment of certain symptoms in secondary Raynaud's phenomenon.[9] It is unclear if it is effective for treating sexual dysfunction in females.[8] It can be taken orally (swallowed by mouth), intravenously (injection into a vein), or through the sublingual route (dissolved under the tongue).[8][10] Onset when taken orally is typically within twenty minutes and lasts for about two hours.[8]

Common side effects include headaches, heartburn, and flushed skin.[8] Caution is advised in those with cardiovascular disease.[8] Rare but serious side effects include vision problems, hearing loss, and prolonged erection (priapism) that can lead to damage to the penis.[8] Sildenafil should not be taken by people on nitric oxide donors such as nitroglycerin (glycerin trinitrate), as this may result in a serious drop in blood pressure.[8]

Sildenafil acts by blocking phosphodiesterase 5 (PDE5), an enzyme that promotes breakdown of cGMP, which regulates blood flow in the penis.[8] It requires sexual arousal to work, and does not by itself cause or increase sexual arousal.[8] It also results in dilation of the blood vessels in the lungs.[8]

Pfizer originally discovered the medication in 1989 while looking for a treatment for angina.[11] It was approved for medical use in the United States and in the European Union in 1998.[5][8][11][12] In 2022, it was the 157th most commonly prescribed medication in the United States, with more than 3 million prescriptions.[13][14] It is available as a generic medication.[15][16] In the United Kingdom, it is available over-the-counter (OTC).[17]

  1. ^ "Sildenafil Use During Pregnancy". Drugs.com. 7 October 2019. Archived from the original on 12 October 2020. Retrieved 6 October 2020.
  2. ^ "Viagra 25mg film-coated tablets - Summary of Product Characteristics (SmPC)". (emc). 7 August 2020. Retrieved 6 October 2020.
  3. ^ "Viagra Connect 50 mg film-coated tablets - Summary of Product Characteristics (SmPC)". (emc). 5 December 2017. Archived from the original on 9 October 2020. Retrieved 6 October 2020.
  4. ^ a b c Cite error: The named reference Viagra FDA label was invoked but never defined (see the help page).
  5. ^ a b "Viagra EPAR". European Medicines Agency. 17 September 2018. Archived from the original on 11 October 2020. Retrieved 6 October 2020.
  6. ^ "Revatio EPAR". European Medicines Agency. 17 September 2018. Archived from the original on 11 November 2020. Retrieved 6 October 2020.
  7. ^ Nichols DJ, Muirhead GJ, Harness JA (6 March 2002). "Pharmacokinetics of sildenafil after single oral doses in healthy male subjects: absolute bioavailability, food effects and dose proportionality". British Journal of Clinical Pharmacology. 53 (Suppl 1): 5S–12S. doi:10.1046/j.0306-5251.2001.00027.x. PMC 1874258. PMID 11879254.
  8. ^ a b c d e f g h i j k l "Sildenafil Citrate". The American Society of Health-System Pharmacists. Archived from the original on 23 April 2020. Retrieved 1 December 2014.
  9. ^ Cite error: The named reference Raynaud's treatment - sildenafil + other PDE5 inhibitors was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference sublingual was invoked but never defined (see the help page).
  11. ^ a b Goldstein I, Burnett AL, Rosen RC, Park PW, Stecher VJ (January 2019). "The Serendipitous Story of Sildenafil: An Unexpected Oral Therapy for Erectile Dysfunction". Sexual Medicine Reviews. 7 (1): 115–128. doi:10.1016/j.sxmr.2018.06.005. PMID 30301707. S2CID 52945888.
  12. ^ "Drug Approval Package: Viagra (sildenafil citrate) NDA #020895". U.S. Food and Drug Administration (FDA). 27 March 1998. Archived from the original on 31 March 2021. Retrieved 15 February 2021.
  13. ^ "The Top 300 of 2022". ClinCalc. Archived from the original on 30 August 2024. Retrieved 30 August 2024.
  14. ^ "Sildenafil Drug Usage Statistics, United States, 2013 - 2022". ClinCalc. Retrieved 30 August 2024.
  15. ^ Gordon S (11 December 2017). "Generic Viagra: Two versions of sildenafil hit the market today". CBS News. Archived from the original on 25 November 2018. Retrieved 24 November 2018.
  16. ^ "Competitive Generic Therapy Approvals". U.S. Food and Drug Administration (FDA). 3 March 2023. Archived from the original on 12 February 2022. Retrieved 6 March 2023.
  17. ^ LaMattina J. "With Viagra Now Available Over-The-Counter In The U.K., Will The U.S. Follow Suit?". Forbes. Archived from the original on 25 November 2018. Retrieved 24 November 2018.