Viagra: Uses, Health Benefits and Risks

Fast facts on Viagra

Here are some key points about Viagra. More detail and supporting information is in the main article.

1. Viagra was initially designed for hypertension and angina pectoris.
    Viagra's main competitors are Cialis (tadalafil) and Levitra (vardenafil).
2. Side effects include headaches, hearing loss, impaired vision, increased intraocular     pressure and dyspepsia.
3. Viagra pills are blue and diamond-shaped.
4. Individuals with kidney disease should not take Viagra.
5. Some athletes take Revatio in the belief that it enhances their performance.
6. Viagra works by inhibiting the enzyme cGMP-specific phosphodiesterase type 5.
7. Viagra was designed by Pfizer in Kent, England.

8. Some people use Viagra recreationally, although it is not thought to have any                 benefit in people without penile dysfunction.

What is Viagra?

Viagra is the brand name for sildenafil citrate, and is used for treating erectile dysfunction and pulmonary arterial hypertension. Originally developed by scientists in Great Britain, it was brought onto the market by Pfizer Inc., a US pharmaceutical company. Viagra is also sold under brand name Revatio.

Sildenafil citrate's chemical formula is C22H30N6O4S.
Viagra works by inhibiting an enzyme called cGMP-specific phosphodiesterase type 5, that delays degradation of cGMP, which controls blood flow in the penis.

Brief history of Viagra

Viagra has become the prime treatment for impotence (erectile dysfunction), competing with Cialis (tadalafil) and Levitra (vardenafil) for market share.

Initially, the drug was designed by Pfizer scientists working in Kent, England. They were in fact working on a drug for hypertension (high blood pressure) and angina pectoris (a symptom of ischemic heart disease). 

During the phase I trials, it was noted that the drug did very little to prevent angina but did induce marked penile erections. Hitting the market in 1998, Viagra was the first oral treatment approved to treat erectile dysfunction in the US.

Viagra's meteoric rise to fame has seen it enter usage as an illicit drug. But, Viagra use in individuals without erectile dysfunction does not seem to have any effect. Although, researchers have noted that there is a significant placebo effect. On a similar note, there is no proven benefit for women taking the drug.


With endorsements from former US Senator Bob Dole and football star Pelé, the drug goes from strength to strength. In 2008, Viagra generated some $1.93 billion of revenue for Pfizer.

Dosage

Viagra, for erectile dysfunction, comes in blue, diamond-shaped pills, in doses of 25, 50, or 100 milligrams. The patient takes a maximum of one pill in a 24-hour period, between 30 minutes to 1 hour before sexual intercourse.


Revatio, for pulmonary arterial hypertension, comes in white, round, film-coated tablets. Patients take one 20 mg Revatio tablet three times a day.

Adverse events for Viagra

According to clinical trial results, the most common side effects include headaches, nasal congestion, impaired vision, photophobia, and dyspepsia. Less commonly, some users have experienced cyanopsia (everything has a tinted blue tinge). 

In very rare cases, Viagra use can lead to vision impairment and nonarteritic anterior ischemic optic neuropathy. Postmarketing surveillance side effects have included (very rare) priapism, heart attack, sudden hearing loss, increased intraocular pressure, and ventricular arryhythmias. Since 2007, its labeling in the US has included a warning of the potential risk of sudden hearing loss.


Viagra can decrease blood supply to the optic nerve, causing sudden vision loss. This very rare adverse event occurred mainly to patients who had heart disease, hypertension, diabetes, high cholesterol, or pre-existing eye problems. Nobody really knows whether the vision loss was caused by the Viagra.

Interactions - HIV patients on protease inhibitors should discuss using Viagra with their doctors - protease inhibitors increase the likelihood and severity of side effects. Experts say such patients should have no more than 25mg, and not more often than every 48 hours.


If the patient is taking alpha blockers, they should make sure they take that medication and Viagra at least four hours apart, to prevent low blood pressure.

Contraindications - the following individuals should not take Viagra (or check with their doctors first):
1.Those on nitric oxide donors, nitrates and organic nitrites
2.Men who are advised to refrain from sexual intercourse because of cardiovascular risk factors
3.Patients with severe hepatic impairment
4.Patients with kidney disease
5.Individuals with low blood pressure (hypotension)
6.Those who have had a recent heart attack
7.Those who have had a recent stroke

8. Individuals with hereditary degenerative retinal disorders.

7 Foods for Better Sex

Avocados

The Aztecs referred to avocados as, ahem, testicles, because of their physical shape. But the scientific reason why avocados make sense as an aphrodisiac is that they are rich in unsaturated fats and low in saturated fat, making them good for your heart and your arteries. Anything that keeps the heart beating strong helps keep blood flowing to all the right places; in fact, men with underlying heart disease are twice as likely to suffer from erectile dysfunction (ED).

Almonds

Topping my list of feisty foods, almonds have long been purported to increase passion, act as a sexual stimulant, and aid with fertility. Like asparagus (another one of my favorite sexy foods), almonds are nutrient-dense and rich in several trace minerals that are important for sexual health and reproduction, such as zinc, selenium, and vitamin E.  “Zinc helps enhance libido and sexual desire,” says Dr. Berman. “We don’t really understand the mechanisms behind it, but we know it 

works.”

Strawberries

The color red is known to help stoke the fire: A 2008 study found that men find women sexier if they’re wearing red, as opposed to cool colors such as blue or green. Strawberries are also an excellent source of folic acid, a B vitamin that helps ward off birth defects in women and, according to a University of California, Berkley study, may be tied to high sperm counts in men. This Valentine’s Day, try making dark-chocolate-dipped strawberries. And while we’re on the subject, there’s a reason we give chocolate on Valentine’s Day: It’s full of libido-boosting methylxanthines.

Seafood

Despite their slippery and slimy texture, oysters may be the most well-known aphrodisiac. They’re also one of the best sources of libido-boosting zinc. But other types of seafood can also act as aphrodisiacs. Oily fish—like wild salmon and herring—contain , which are essential for a healthy heart.

Arugula

Arugula has been heralded as an arousal aid since the first century. Today, research reveals that the trace minerals and antioxidants packed into dark, leafy greens are essential for our sexual health because they help block absorption of some of the environmental contaminants thought to negatively impact our libido.

Figs

These funny-shaped fruits have a long history of being a fertility booster, and they make an excellent aphrodisiac because they are packed with both soluble and insoluble fiber, which is important for heart health. Plus, high-fiber foods help fill you up, not out, so it’s easier to achieve that sexy bottom line—or belly.

Citrus

Any member of this tropical fruit family is super-rich in antioxidants, vitamin C, and folic acid—all of which are essential for men’s reproductive health. Enjoy a romantic salad that incorporates citrus, like pink grapefruit or mandarin oranges, or use a dressing made with lemon and lime.