Editing Sildenafil (section)

==History==
Sildenafil (compound UK-92,480) was synthesized by a group of pharmaceutical chemists led by [[Simon Campbell]]<ref name="RPS2014">{{cite journal |title=Scientist who developed Viagra receives knighthood in New Year's Honours |journal=The Pharmaceutical Journal |publisher=Royal Pharmaceutical Society |year=2014 |issn=2053-6186 |doi=10.1211/pj.2014.20067494 |url=https://pharmaceutical-journal.com/article/news/scientist-who-developed-viagra-receives-knighthood-in-new-years-honours |access-date=14 January 2023 |archive-date=14 January 2023 |archive-url=https://web.archive.org/web/20230114090526/https://pharmaceutical-journal.com/article/news/scientist-who-developed-viagra-receives-knighthood-in-new-years-honours |url-status=live }}</ref> working at Pfizer's [[Sandwich, Kent]], research facility in England. It was initially studied for use in [[hypertension]] (high blood pressure) and [[angina pectoris]] (a symptom of [[ischaemic heart disease]]).<ref name="pmid16883306">{{cite journal |vauthors=Ghofrani HA, Osterloh IH, Grimminger F |title=Sildenafil: from angina to erectile dysfunction to pulmonary hypertension and beyond |journal=Nat Rev Drug Discov |volume=5 |issue=8 |pages=689–702 |date=August 2006 |pmid=16883306 |pmc=7097805 |doi=10.1038/nrd2030}}</ref> The first clinical trials were conducted in [[Morriston Hospital]] in [[Swansea]].<ref>{{cite web| title=Research | url=http://www.abm.university-trust.wales.nhs.uk/page.cfm?orgId=743&pid=29457 | date= 4 July 2008 | access-date=6 August 2008|archive-url = https://web.archive.org/web/20080926034946/http://www.abm.university-trust.wales.nhs.uk/page.cfm?orgId=743&pid=29457|url-status = dead|archive-date = 26 September 2008|publisher = Abertawe Bro Morgannwg University Health Board|website = ABM|quote = 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!}}</ref> Phase I [[clinical trial]]s under the direction of [[Ian Osterloh]] suggested the drug had little effect on angina, but it could induce marked penile [[erection]]s.<ref name="autogenerated47">{{cite journal | vauthors = Boolell M, Allen MJ, Ballard SA, Gepi-Attee S, Muirhead GJ, Naylor AM, Osterloh IH, Gingell C | title = Sildenafil: an orally active type 5 cyclic GMP-specific phosphodiesterase inhibitor for the treatment of penile erectile dysfunction | journal = International Journal of Impotence Research | volume = 8 | issue = 2 | pages = 47–52 | date = June 1996 | pmid = 8858389 }}</ref><ref>{{cite journal |vauthors=Terrett NK, Bell AS, Brown D, Elllis P | title = Sildenafil (Viagra), a potent and selective inhibitor of Type 5 cGMP phosphodiesterase with utility for the treatment of male erectile dysfunction | journal = Bioorg Med Chem Lett | year = 1996 | volume = 6 | pages = 1819–24 | doi = 10.1016/0960-894X(96)00323-X |issue=15 }}<!--not indexed on Medline--></ref> Pfizer therefore decided to market it for erectile dysfunction, rather than for angina; this decision became an often-cited example of [[drug repositioning]].<ref>{{cite journal | vauthors = Ashburn TT, Thor KB | title = Drug repositioning: identifying and developing new uses for existing drugs | journal = Nature Reviews. Drug Discovery | volume = 3 | issue = 8 | pages = 673–83 | date = August 2004 | pmid = 15286734 | doi = 10.1038/nrd1468 | s2cid = 205475073 }}</ref><ref>{{cite book|last1=Institute of Medicine|title=Drug Repurposing and Repositioning: Workshop Summary|date=2014|publisher=National Academies Press|isbn=9780309302043|url=https://www.nap.edu/catalog/18731/drug-repurposing-and-repositioning-workshop-summary|access-date=11 June 2017|archive-date=22 April 2019|archive-url=https://web.archive.org/web/20190422054824/https://www.nap.edu/catalog/18731/drug-repurposing-and-repositioning-workshop-summary|url-status=live}}</ref> The drug was [[patent]]ed in 1996, approved for use in erectile dysfunction by the FDA on 27 March 1998, becoming the first oral treatment approved to treat erectile dysfunction in the United States, and offered for sale in the United States later that year.<ref>{{cite journal| vauthors = Kling J |title=From hypertension to angina to Viagra|journal=Mod. Drug Discov.|year=1998|volume=1|pages=31–38|url=<!--http://pubs.acs.org/hotartcl/mdd/98/novdec/viagra.html deadlink not required in present instance. The article is present as a TOC entry at http://pubs.acs.org/subscribe/archive/mdd/toc/1198toc.html . -->|issn = 1532-4486|oclc = 41105083}} <!--Not indexed on PubMed--></ref> It soon became a great success: annual sales of Viagra peaked in 2008 at US$1.934 billion.<ref>{{cite web|url=https://www.sec.gov/Archives/edgar/data/78003/000119312511048877/dex13.htm|title=Portions of the 2010 Financial Report|access-date=15 July 2016|archive-date=10 June 2019|archive-url=https://web.archive.org/web/20190610193252/https://www.sec.gov/Archives/edgar/data/78003/000119312511048877/dex13.htm|url-status=live}}</ref>{{globalise-inline|date=December 2023}}