VIAGRA (Sildenafil Citrate)

Viagra for the Treatment of Erectile Dysfunction

When it comes to prescription drugs, few have enjoyed the kind of fanfare and fame that Viagra has. Since hitting the market in late 1998, “the little blue pill,” as it was famously marketed by Pfizer for some time, has revolutionized the way in which erectile dysfunction is treated. Before Viagra, the only viable and reliable way to treat certain types of ED was through a painful injection straight to the penis. That solution never really caught on, but Viagra certainly did.

Several similar drugs have become available since, but none has come close to matching Viagra’s popularity or general ubiquity. Viagra is such a mainstay now that most people have little or no idea about how it actually works, and many take it for granted. Like any drug, significant research led to its development, and certain precautions are in order for those who use it to treat erectile dysfunction.

Erectile Dysfunction and Viagra

When the penis functions properly, it becomes erect when a man is sexually stimulated. The penis does not become erect through the actions of muscles. Rather, it becomes erect through the strategic flow of blood through two matching, tube-shaped structures known as the corpora cavernosa.

Arteries deliver blood to the corpora cavernosa, and veins carry it away. The penis becomes limp or erect depending on the direction in which blood is flowing. In its non-erect state, the arteries are somewhat restricted, and the veins are open. Pressure is unable to build.

When a man becomes sexually aroused, arteries in the corpora cavernosa open up, the veins constrict and the tube-like structures fill up rapidly with blood. This causes the penis to stiffen and elongate, which allows a man to continue to be stimulated until ejaculation occurs.

The most common cause of erectile dysfunction occurs when these arteries fail to open up properly. To achieve an erection, something must be done to ensure that the arteries open and remain open, and that is precisely what Viagra does.

The Chemistry of an Erection

To gain an even clearer understanding of how Viagra, or sildenafil citrate, works, it’s necessary to delve into the chemical and physiological mechanisms behind an erection.

As blood flows through the body, it is directed where it needs to go through chemical processes in the brain. Certain enzymes cause smooth muscles lining arteries and veins when to relax and when to constrict. More specifically, an enzyme called cGMP makes this happen. Meanwhile, an enzyme called PDE deactivates the effects of cGMP.

There are 11 types of PDE. One in particular, PDE5, is responsible for deactivating the effects of cGMP in the penis. When researchers made this discovery, they knew they were onto something. Research had already determined that erectile dysfunction often occurred when arteries in the penis failed to dilate enough for the corpora cavernosa to fill with blood.

Pfizer researchers and scientists determined that by inhibiting PDE5, they could effectively promote the buildup of cGMP in the penis. Conveniently, PDE5 only affects the penis. Once this discovery was made, the development of Viagra zoomed full speed ahead.

How Viagra Works

The way Viagra works is as ingenious as it is simple. The drug simply inhibits the production of the pesky PDE5 enzyme, which allows cGMP to build up to the level that is needed to produce and maintain an erection. By selectively blocking PDE5, Viagra has a positive effect on the walls of the arteries in the corpora cavernosa. In turn, they are able to dilate sufficiently, which allows blood to flow into these tube-like structures.

One of the most ingenious things about Viagra is that it is designed to work only when a man is stimulated sexually. Prior to the development of Viagra, the only reliable way to counteract the effects of insufficient levels of cGMP in the penis was through the injection of a drug called phentolamine. This drug worked to open arteries in the immediate vicinity, so it had a similar effect as Viagra. The problem, however, was that it would produce this effect whether or not a man was sexually aroused. Also, few men savored the idea of injecting their penis with medicine, so scientists knew that it was not a viable long-term solution for ED.

A Brief History of Viagra

Viagra was originally studied for use in the treatment of hypertension. While studying the effects of the drug in trials, however, scientists discovered that it had a direct effect on a man’s ability to achieve and maintain an erection. Thus, researchers switched gears and began developing the drug with the treatment of erectile dysfunction in mind.

Viagra was patented in 1996. From there, things happened very quickly. It was approved for use in the treatment of erectile dysfunction by the FDA on March 27, 1998. This made it the first oral treatment for ED in the United States. Later that year, Viagra officially started being sold in the U.S. It immediately became widely prescribed. At its height, in 2008, sales of Viagra in the U.S. totaled more than $1.9 million.

How to Use Viagra

In addition to being highly effective for the treatment of erectile dysfunction, Viagra has generally been an affordable choice. Viagra prices tend to be reasonable, and the drug is often covered by insurance. As ubiquitous and affordable as it may be, however, those who are prescribed it should take care when using it.

Viagra should be stored at room temperature and kept away from moisture and heat.

Viagra is an oral medication. As it was marketed, it is a “little blue pill.” Unlike many prescription medications, however, it is not designed to be taken at a certain time every day. Rather, it should be taken prior to sexual activity.

Viagra should be taken orally at least 30 minutes prior to sexual activity. It should not be taken more than four hours beforehand, however. The best time to take it is about an hour before sexual activity is expected to occur. It should not be taken more than once daily, and it should never be used without the care and supervision of a doctor.

The recommended dosage of Viagra varies from person to person. It depends largely on a person’s response to treatment, his medical condition, and other medications that he is currently taking.

Contraindications

In medical parlance, a contraindication is a situation in which a drug may be harmful to a patient. Because Viagra affects blood flow and the performance of blood vessels and arteries in the body, it is not recommended for use under certain circumstances.

The most common and important contraindications for Viagra include:

• the use of organic nitrates/nitrates or nitric oxide donors, which are commonly prescribed for the treatment of chest pain and certain heart problems
• decreased liver function
• hypotension, or low blood pressure
• certain hereditary degenerative retinal disorders
• restrictions on sexual activity due to cardiovascular risk factors
• severe impairment in renal functioning
• recent heart attack or stroke
• stomach ulcer
• blood cell disorders, including leukemia and sickle cell anemia
• bleeding disorders like hemophilia
• physical deformity of the penis, including Peyronie’s disease

Although it specifically inhibits the PDE5 enzyme, Viagra also affects the PDE6 enzyme, which involves cone cells in the retina. As a result, it may decrease blood flow to the optic nerve of the eye. This is more likely in patients who have diabetes, high blood pressure, pre-existing eye problems, smokers, those aged 50 and older, and people with high cholesterol.

Additionally, Viagra may cause undesirable interactions when taken with the following drugs:

• cimetidine, which is commonly prescribed for heartburn
• erythromycin, an antibiotic
• protease inhibitors, which are used in the treatment of HIV and may increase the incidence and severity of certain side effects

Viagra Side Effects

As effective as it may be, Viagra may produce side effects in some patients. Some side effects are relatively minor and easy to deal with while others are quite serious and require immediate medical attention.

In clinical trials, the most common – and least worrisome – Viagra side effects include:

• dyspepsia, or indigestion
• headache
• flushing of the face
• impaired vision, which may include cyanopsia, in which the vision is tinted blue; a loss of peripheral vision or blurred vision
• nasal congestion
• ringing in the ears
• chest pain or a feeling of heaviness with pain spreading to the shoulders and/or arms
• shortness of breath
• feeling light-headed
• swelling in the ankles, feet, and/or hands

Rare but potentially serious Viagra side effects include:

• severe hypotension, or extremely low blood pressure
• priapism, or an erection that is painful and/or lasts for four hours or longer
• heart attack
• stroke
• ventricular arrhythmia
• increased intraocular pressure
• sudden hearing loss
• sudden vision loss

If any of the following symptoms occur while taking Viagra and having sexual intercourse, patients should stop and contact their doctor immediately:

• numbness, pain, or tingling in the neck, chest, arms, or jaw
• nausea or dizziness

Is Viagra Safe?

When used as directed and under the supervision of a doctor, Viagra is an overwhelmingly safe drug. However, patients must be educated regarding the possible side effects of the medication and need to know when they should contact their doctor or seek emergency medical care. Unfortunately, the popularity of Viagra has made it a common choice for recreation use. This is not recommended as it can lead to serious health problems.

Obtaining Viagra Online

Viagra is only available by prescription, so the first step in obtaining the drug is by consulting with a doctor. Typically, a patient undergoes a physical examination and answers questions posed by the doctor regarding his sexual history.

While many patients opt to fill their Viagra prescriptions at local pharmacies, many find more competitive Viagra prices online. Indeed, it is becoming increasingly common for patients to purchase Viagra online. Even when purchased online, however, a prescription for Viagra is still needed.

Although Viagra works remarkably well in the treatment of erectile dysfunction, it isn’t effective for everyone. With that in mind, many people prefer to try Viagra samples before investing money in normal supplies of the medication. Fortunately, many doctors offer Viagra samples that patients can use to see if the drug is effective for them.

The Bottom Line on Viagra

Viagra is a very effective treatment for certain types of erectile dysfunction. However, if the ED is occurring for reasons that don’t involve the failure of arteries to properly dilate, it will not be effective. When it works, however, it tends to do so very reliably, and there is typically nothing wrong with using the drug over long periods of time.