Viagra® (sildenafil citrate) is a registered trade mark of Pfizer Inc and is widely known as the world’s most popular drug for treating erectile dysfunction (impotence). You may have heard of Viagra, as its popularity across Europe indicates – it is one of the best-selling pharmaceutical products globally, with around 100 million prescriptions written annually. The drug is also available in a range of countries outside Europe, such as Japan, in which it is known as Sildenafil and in Australia, where it is available under the tradename Viagra®.
Despite its popularity, Viagra is a fairly new arrival in the world of medications and was only approved for sale in the UK back in 1998. Since then, Pfizer has registered it around the world and it is now widely available, making it easier for physicians to prescribe and patients to obtain. However, as with most new drug developments, physicians and pharmacists are still exploring the optimal way to use Viagra in combination with other medications and in various treatment regimens, as well as its side effects and interactions with other products, food and supplements.
The History of Viagra
The development of Viagra was highly complex and involved many laboratories, as you might expect from a medication that was first produced to combat impotence. It was actually developed as a response to problems Pfizer had encountered, when trying to develop a new form of therapy for heart disease. Between 1989 and 1992, Pfizer worked with a team of doctors and scientists to create a new drug, named sildenafil, which would be effective for men with erectile dysfunction and which could not be easily tampered with by drug abusers. This is because sildenafil is a substance derived from nature and is extremely specific in its action – it only affects the activity of certain proteins (enzymes) that are present in the body, mainly in the blood vessels of the penis. Thus, while the rest of the body attempts to break down and eliminate sildenafil, it will remain in the blood vessels and continue to exert its intended effects.
In early 1992, Pfizer filed for the registration of Sildenafil in the UK and it was approved for prescription by doctors in that country, the same year. After further trials and testing, the drug was approved for sale in the form of a tablet to be taken once or twice a day and at a recommended dose of 50 milligrams per tablet. Since then, sildenafil has been approved for use in more than 100 countries around the world and it is currently available in almost all of them.
How Viagra Works
As mentioned above, sildenafil is a substance that is derived from nature and is extremely specific in its mode of action. This specificity means that it will interact with a protein (P450 CYP3A4) that is present in the body, but which is not necessarily involved in the metabolism of sildenafil. Thus, while other medications may interfere with this enzyme and affect the way in which sildenafil itself is metabolized, this interference will only affect a small number of molecules and not the entire population of enzymes. This is why sildenafil is often described as a “super drug” and why it is so effective at increasing the availability of other medications in the body. It also explains why the side effects of sildenafil are generally mild and why it is such a safe treatment for erectile dysfunction, as it will not interfere with normal body function in most cases.
When sildenafil is taken by a man, it will enter the blood stream and then be transported to the corpus cavernosum (pelvic floor muscles), where it will bind to a specific receptor site and activate an enzyme (cyclic guanosine monophosphate – cGMP) that causes blood vessels to relax and become capable of widening, inspiring sustained erections. Sildenafil is thus considered a “relaxant”, as it induces penile erection by relaxing the blood vessels in the penis and therefore has a similar mode of action to that of an antihypertensive (medication used to treat high blood pressure). In combination with sexual stimulation, the amount of blood that enters the penis will increase and the man will experience an erection, which will then persist for some time, after the sexual activity has ceased.
The Difference between Sildenafil and Viagra
Now, it is important to note that although sildenafil and Viagra have many similar characteristics and share the same potency as a substrate for P450 CYP3A4, they are not identical. This is because Viagra is a registered trade mark of Pfizer and so it bears the company’s name upon it, as well as indicating that it was approved for sale in the UK and other European countries in the 1998 registration year. Furthermore, while all sildenafil medication is capable of inducing penile erections in men, Viagra is specifically designed to do this and is therefore more effective at increasing blood flow into the penis, than any other type of sildenafil medication.
This difference in effect means that although both sildenafil and Viagra are effective at increasing the length and rigidity of the penis, it is not necessarily the case that every dose of the latter will have the same effect as every dose of the former. On the other hand, as previously stated, Viagra is a registered trade mark and so it is a more effective medication than sildenafil, if you are seeking a treatment for erectile dysfunction in countries where it is available and approved for sale. Therefore, if you are seeking treatment for erectile dysfunction in a country where sildenafil is approved, then you will need to try a different product and so, in this sense, Viagra is not a generic medication and does not provide a “better than required” or “just-in-case” treatment for erectile dysfunction.
The Side Effects of Viagra
As mentioned above, sildenafil is a relatively new medication and Pfizer only began registering it for sale in Europe and other parts of the world in 1997, so there is not a vast amount of medical data available regarding its side effects. However, what we do know is that sildenafil has fairly innocuous side effects, which are generally comparable to those of other medicines used to treat cardiovascular disease. Thus, like other medications that reduce blood pressure, sildenafil may cause headaches, particularly in the morning, as well as lethargy and drowsiness. Furthermore, while the drug appears to be safe for most men, it may cause harm in those who are already suffering from erectile dysfunction or who are taking other medications that may cause hypotension (low blood pressure). In such cases, sildenafil may actually aggravate the problem, as it will reduce the blood pressure sufficiently for the man to experience headaches, as mentioned above.
However, in other cases, the side effects of sildenafil may be of benefit and the drug may even be therapeutically superior to other treatments, as it will, in most cases, increase the effectiveness of other medications and so provide a better outcome for the patient. Thus, while sildenafil has fairly innocuous side effects and is a safe treatment for erectile dysfunction, it may, in some cases, be a better treatment option than other medications or supplements. This is because it will, in almost all cases, make other medications more effective or provide a better outcome for the patient.