Cookie policy: This site uses cookies (small files stored on your computer) to simplify and improve your experience of this website. Cookies are small text files stored on the device you are using to access this website. For more information please take a look at our terms and conditions. Some parts of the site may not work properly if you choose not to accept cookies.

Join

Subscribe or Register

Existing user? Login

Drugs used in erectile dysfunction

Three decades of Viagra

Sildenafil (Viagra) — the first oral drug for erectile dysfunction to hit the market in 1998 — has been prescribed for more than 64 million men worldwide, and may soon be reclassified as a pharmacy medicine in the UK.

Infographic showing the history of sildenafil (Viagra)

View the full infographic here.

Drug approvals and market developments

Sildenafil showed promise as an oral treatment for erectile dysfunction (ED) in the early 1990s and was launched by Pfizer as Viagra in 1998. Since then three more PDE5 inhibitors have been launched in the UK.

1989: Sildenafil, a drug that selectively targets and powerfully inhibits the enzyme phosphodiesterase type 5 (PDE5), is first synthesised and tested in Pfizer’s UK laboratories.

1991:  The first trial of sildenafil for coronary heart disease shows it is ineffective but penile erection is noticed as a side effect.

1998: Pivotal phase III trial of sildenafil for ED is published in The New England Journal of Medicine.

1998: Sildenafil (Viagra; Pfizer) is approved by the US Food and Drug Administration (FDA) in March and the European Medicines Agency (EMA) in September as the first oral treatment for men with ED.

2002: Tadalafil (Cialis; Eli Lilly) is approved for the treatment of ED by the EMA in November, and by the US FDA in November the following year.

2003:  Vardenafil (Levitra; Bayer) is approved by the EMA for the treatment of ED in March and the US FDA in August.

2007:  The European Commission approves low-dose (2.5mg and 5.0mg) tadalafil as single-daily ED therapy.

2008:  Pfizer withdraws an application to the EMA to market Viagra over the counter for ED after the regulator expresses concerns that there would be no medical supervision, which could delay diagnosis of possible cardiovascular disease.

2009: Boots becomes the first UK pharmacy to offer Viagra without a prescription under a patient group direction.

2010:  Tesco breaks into the Viagra market and offers the drug to customers without a prescription under a patient group direction.

2010: Vardenafil (10mg) is the first PDE5 inhibitor introduced for ED in an orodispersible tablet.

2012: Avanafil (Spedra; Vivus) is approved for treatment of ED by the US FDA in April and by the EMA in June 2013.

2013:  The UK patent on Viagra expires, opening the way for generic versions of sildenafil to be launched.

2014: Manufacturer of Cialis, Lilly, agrees a deal with Sanofi to allow the French firm to buy exclusive rights to apply to sell Cialis as a non-prescription medicine in Europe, the United States, Canada and Australia after certain patents expire.

2014: Generic sildenafil can now be prescribed on the NHS for any male with ED, whereas previously it was restricted to those with ED because of an underlying health condition, such as diabetes or prostate cancer. 

2017: The Medicines and Healthcare products Regulatory Agency (MHRA) recommends sildenafil 50mg (Pfizer) should be available as a pharmacy medicine, and launches a consultation that closes in April.

Usage and cost data for PDE5 inhibitors

The number of prescription items dispensed in England for the four PDE5 inhibitors has been influenced by their cost and restrictions on prescribing them within the NHS.

Graph showing number of PDE5 inhibitors items dispensed in england 17

Number of prescription items dispensed in England

1. Introduction of low-price generic sildenafil and removal of prescribing restrictions led to a steep rise in the number of prescription items dispensed in England, from 1.3 million in 2012–2013 to 2.7 million in 2015–2016.
2. Branded tadalafil, vardenafil and avanafil, and Viagra, continue to be restricted on the NHS, so as prescriptions for sildenafil rose, those for tadalafil and vardenafil began to fall.
3. Avanafil (2015–2016): 6,765

Graph showing net ingredient cost of prescription pde5 inhibitors dispensed

Net ingredient cost of prescription items dispensed

1. The net ingredient cost for sildenafil fell from £40.2m in 2012–2013 to £5.8m in 2015-2016, reflecting a fall in the cost per prescription item from £31.22 to £2.20
2. Avanafil (2015–2016): £148,113

PDE5 inhibitors: key facts

PDE5 inhibitors work by increasing blood flow to the penis during sexual stimulation. Although all PDE5 inhibitors are effective, there are differences in their onset and duration of action. There are also differences in how their absorption is affected by food, and in their side effect profiles.

Key facts of PDE5 inhibitors: Sildenafil, Tadalafil, Vardenafil and Avanafil

Citation: The Pharmaceutical Journal DOI: 10.1211/PJ.2017.20202847

Have your say

For commenting, please login or register as a user and agree to our Community Guidelines. You will be re-directed back to this page where you will have the ability to comment.

Recommended from Pharmaceutical Press

Search an extensive range of the world’s most trusted resources

Powered by MedicinesComplete
  • Print
  • Share
  • Comment
  • Save
  • Print Friendly Version of this pagePrint Get a PDF version of this webpagePDF

Supplementary images

  • Infographic showing the history of sildenafil (Viagra)
  • Graph showing number of PDE5 inhibitors items dispensed in england 17
  • Graph showing net ingredient cost of prescription pde5 inhibitors dispensed
  • Key facts of PDE5 inhibitors: Sildenafil, Tadalafil, Vardenafil and Avanafil

Supplementary information

Jobs you might like

See more jobs

Newsletter Sign-up

Want to keep up with the latest news, comment and CPD articles in pharmacy and science? Subscribe to our free alerts.