# What ever happened to the original Viagra? **URL:** \ **Category:** Factual Questions\ **Created:** [May 9, 2004, 6:33am UTC](https://boards.straightdope.com/t/what-ever-happened-to-the-original-viagra/244272 "2004-05-09T06:33:17Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![dnooman](https://avatars.discourse-cdn.com/v4/letter/d/839c29/32.png) [@dnooman](https://boards.straightdope.com/u/dnooman)\ **Post date:** [May 9, 2004, 6:33am UTC](https://boards.straightdope.com/t/what-ever-happened-to-the-original-viagra/244272/1 "2004-05-09T06:33:17Z")
I know that Viagra was initially developed as a heart medication. What happened to that vein of research? Does Viagra do anything specifically good for the heart? Is there another drug that benifited from Viagra research, or did things just stop when the test group refused to give back their extra doses? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 9, 2004, 6:23pm UTC](https://boards.straightdope.com/t/what-ever-happened-to-the-original-viagra/244272/2 "2004-05-09T18:23:47Z")
[The Viagra™ story](http://www.schoolscience.co.uk/content/4/biology/viagra/viagch5pg1.html): > [@](#): > > In 1991, trials looked at how effectively Viagra™ treated angina. Researchers wanted to see if it dilated the coronary arteries feeding the heart muscle and relieved the pain of angina. Results showed it would not be a good treatment for angina. However, some subjects reported some interesting side effects. > > In small scale studies, some healthy volunteers reported that Viagra™ enhanced erections and so, in 1992, researchers changed direction and concentrated on developing Viagra™ as a treatment for erectile dysfunction. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [May 10, 2004, 12:05am UTC](https://boards.straightdope.com/t/what-ever-happened-to-the-original-viagra/244272/3 "2004-05-10T00:05:41Z")
> [@](#): > > Results showed it would not be a good treatment for angina. However, some subjects reported some interesting side effects. > > In small scale studies, some healthy volunteers reported that Viagra™ enhanced erections… That doesn’t make any sense. Men don’t have anginas. Ba-dum-dum! :o ---
**Author:** ![kelly5078](https://avatars.discourse-cdn.com/v4/letter/k/6f9a4e/32.png) [@kelly5078](https://boards.straightdope.com/u/kelly5078)\ **Post date:** [May 10, 2004, 4:07pm UTC](https://boards.straightdope.com/t/what-ever-happened-to-the-original-viagra/244272/4 "2004-05-10T16:07:35Z")
Does nitroglycerin, which is an effective vasodilator for treating angina, have the same interesting side-effect as Viagra? ---
**Author:** ![alimarx](https://avatars.discourse-cdn.com/v4/letter/a/e274bd/32.png) [@alimarx](https://boards.straightdope.com/u/alimarx)\ **Post date:** [May 10, 2004, 6:06pm UTC](https://boards.straightdope.com/t/what-ever-happened-to-the-original-viagra/244272/5 "2004-05-10T18:06:17Z")
> [@kelly5078](#): > > Does nitroglycerin, which is an effective vasodilator for treating angina, have the same interesting side-effect as Viagra? Both do have a tendency to create explosions of some sort… 😛 I think this whole thread will be begging these puerile jokes… ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 10, 2004, 6:20pm UTC](https://boards.straightdope.com/t/what-ever-happened-to-the-original-viagra/244272/6 "2004-05-10T18:20:57Z")
> [@kelly5078](#): > > Does nitroglycerin, which is an effective vasodilator for treating angina, have the same interesting side-effect as Viagra? Probably not. Nitroglycerin has been in use to treat angina for a few decades, and there have not been any significant number of reports of enhanced erectile function, that I’m aware of. Additionally, the action of [Viagra](http://www.endocrinology.org/SFE/viagra.htm) in enhancing erections is different than tha vasodilation action of nitroglycerin. Rather than actively dilating blood vessels, Viagra inhibits an enzyme which breaks down a chemical that causes arterial wall relaxation: > [@](#): > > In response to sexual excitement, the parasympathetic nerves in the penis release nitric oxide which stimulates the enzyme guanylate cyclase to produce cyclic GMP. Cyclic GMP relaxes arterial smooth muscle. Cyclic GMP is then broken down by a specific enzyme in the penis called phosphodiesterase type 5. Viagra® inhibits this enzyme (2). By preventing breakdown of cyclic GMP, Viagra® prolongs arterial relaxation and inflow of arterial blood and thereby enhances erection. Its mode of action explains why, to be effective, Viagra® requires the patient be exposed to sexual stimuli - ie, it causes erections only in the context of sexual arousal.