Introduction

Viagra (sildenafil) is the brand name for the diamond-shaped blue pill that has revolutionised the treatment of male erectile dysfunction (known as ED) over the last fifteen years.

Erectile Dysfunction (ED)

Erectile dysfunction (ED) is the inability to get and/or maintain an erection that is sufficient for satisfactory sexual intercourse. It is also known as impotence. It is unusual for a man never to have experienced a failure to achieve or maintain an erection at some point and for some reason, and this occasional temporary occurrence can be attributed to a number of factors, such as excess alcohol, or being unwell. ED is usually the term used when this problem occurs more than occasionally, and treatment is desired. It is very common in older men. It is estimated that half of all men between the ages of 40 to 70 will have some degree of ED.

ED can have a range of causes that can be both physical and psychological (mental). Physical causes include the narrowing of the blood vessels going to the penis - commonly associated with high blood pressure (hypertension), high cholesterol or diabetes (a condition caused by too much glucose in the blood). Psychological causes of ED include depression, stress (such as at work), anxiety and relationship problems.

While ED can have a significant impact on both your quality of life and your partner’s, ED can be treated in many cases. It is important that a healthcare professional diagnoses ED so that the root cause can be identified. Medication and other treatments can be used to successfully manage it in more than two-thirds of men.

Discovery of Viagra

Viagra was never intended to treat ED. A group of pharmaceutical chemists at Pfizer’s Sandwich, a research facility in Kent (England), worked together to synthesize a compound named Sildenafil. The medicine was initially formulated to treat hypertension angina pectoris (a symptom of ischaemic heart disease) and chest pains caused from the inadequacy of the blood circulation to the heart. The drug was tried on men in Morriston Hospital (Swansea), in 1991 & 1992. The clinical trials suggested that the drug had very little effects on treating angina, but marked significant changes in penile erections.

Following the clinical trial and the discovery that Sildenafil was good for those suffering from ED, Pfizer decided to commercialize the drug, as Viagra, as a remedy for erectile dysfunction. The medicine was patented in 1996.

Not much time later, a full-blown marketing strategy was adapted to promote the use of Viagra (Sildenafil). Some prominent figures in the United States, including the Senator Bob Dole and soccer star Pelé, endorsed the product. The Internet was also used to promote Viagra. Numerous websites were authorized to sell the drug, after an online consultation. With this, the options for people intending to buy Viagra had grown manifold.

Sales of Viagra dropped drastically by 2007, due to the entry of its rival brands – Cialis and Levitra. Several other counterfeits and clones of Viagra also mushroomed in the market, which led to a drop in the sales of the original brand.

‘Boots’, UK’s most popular chemist, announced the sales of over-the-counter Viagra tablets in February 2007, in its stores located in Manchester (England). After the announcement, men aged between 30 and 65 years were allowed to buy four over-the-counter tablets of Viagra, at a time. A simple consultation with a pharmacist was what was required by the consumers, to buy the pills. It is anticipated that Pfizer’s worldwide patents on sildenafil will reach its expiration date in 2011-2013.

Treatment of ED with Viagra

Viagra belongs to a group of medicines called PDE5 inhibitors. The blue diamond-shaped pill is an oral tablet, which is swallowed with water. For Viagra to be effective sexual stimulation is required; it will not create an erection unless a man engages in sexually stimulating activity.

Viagra works by helping the blood vessels to the penis to let more blood flow. This helps to create and keep an erection. This increased blood flow is achieved by relaxing the blood vessels that supply blood to the penis. Viagra works for around four hours after being swallowed. The most important advantage of Viagra over other PDE5 inhibitors (such as Cialis and Levitra- see below) is that it has a very strong safety profile.  Viagra has been tested in hundreds of controlled clinical trials with thousands of patients.  It has also been successfully used by over 23 million men worldwide since it was released in 1998.  Levitra, on the other hand, has only been on the market since 2003 and has not been used or tested to the extent of Viagra. Other than safety concerns, the main reason why males with ED prefer Viagra is because of erection quality.  Men who have used both Viagra and Levitra report that they have better results when taking Viagra including firmer, higher quality erections. Though the effects of Viagra are not as long-lasting as with Levitra, most men preferred to have more rigid erections over lengthier results.

If Viagra is taken after a heavy meal, or with alcohol, its effectiveness will be reduced.

Side Effects of Viagra

Like all drugs you take, there are some side effects to Viagra which are:

• Headache
• Flushing of the face and throat
• Upset stomach
• Stuffy nose
• Urinary tract infection

Visual changes such as mild and temporary changes in blue/green colours or increased sensitivity to light.

Not everyone will experience some or any of these, and when they do they are typically temporary and mild.

After taking Viagra, a few men have experienced a continuing erection. If it lasts over 4 hours then a doctor should be consulted immediately.

Comparison Viagra with other treatments for ED

Cialis (Tadalafil)

Cialis works in a similar fashion to Viagra, also belonging to a group of medicines called PDE5 inhibitors. Cialis comes as an almond shaped yellow tablet to be taken as needed before sex and no more than one pill a day. It is an oral tablet, which is swallowed. For Cialis to be effective sexual stimulation is required and so Cialis will not create an erection unless a man engages in sexually stimulating activity.

Cialis can work for up to 36 hours, and should be taken at least 30 minutes before the man wishes to have sex. Because of this longevity, Cialis is sometimes known as the “The weekend” pill”.

Levitra (Vardanafil)

Levitra works in a similar fashion to Viagra and Cialis except that on average it takes between 25 minutes to one hour although some men will achieve an erection within 15 minutes. Within a 5 hour period after taking the tablet an erection should occur in response to sexual stimulation. The action of Levitra is not generally affected by eating before taking the treatment (except where the meal has a high fat content) or by drinking alcohol, so men can eat or drink as they would normally before taking Levitra.

Availability of Viagra

In England Viagra can be prescribed by a GP (General Practitioner) and thereafter repeat prescriptions can usually be obtained without having to make appointments. Viagra is also available online, and can be ordered after an online consultation, which usually involves completing a questionnaire, which is then examined by a doctor. If approved, the pills will then be despatched. Prices are generally cheaper than over the counter in Pharmacies, especially if bought in bulk. However, there are many fake Viagra tablets advertised on line, all claiming to be as good as the real thing. The usually have names similar to Viagra, like Kamagra.