Today, Viagra is practically synonymous with impotence treatment. “The little blue pill” achieved such a global success that it’s became not only the most sold ED treatment in history, but also a true icon of popular culture. No matter which segment of this extreme success and popularity of this ED pill we choose to consider, the secret always lies at sildenafil, the active ingredient of Viagra.

Sildenafil was the first of its kind, in multiple ways. The discovery of this substance was, at the same time, the discovery of a whole new class of pharmaceutical compounds, called PDE-5 inhibitors. The unique mechanism of action of sildenafil paved the way for all ED pills that came after it, changing the way impotence is thought of and treated in the 21st century. Prior to this, all available treatments were very unpleasant to use, unreliable, and bordering pseudoscience. The discovery of sildenafil changed it all and opened a new chapter in the treatment of erectile dysfunction.

What’s on this page?

The discovery of Sildenafil

Earliest research into sildenafil became in the early 1990s, but it wasn’t until the end of that decade that it was finally patented and presented to the public. Pfizer’s experts in chemistry were working on a new medicine, intended for the treatment of angina pectoris, blood clots and related cardiovascular conditions in the town of Sandwich, Kent. However, by the time the clinical trials begun in Morriston Hospital in Swansea, Wales, it was obvious to the researchers that sildenafil wasn’t as effective as they hoped. However, a curious side effect has been noticed in the process.

After this, Pfizer scientists were encouraged by the results so much that they decided to change the final aim of the project and develop sildenafil as a treatment for erectile dysfunction instead. By 1996, sildenafil (then called compound UK/92,480) was patented by a team of scientists who were working for Pfizer’s research facility1. Two years later, the newly discovered sildenafil-based medicine called Viagra finally reached the shelves of the pharmacies across Europe and the US, after being approved both by the EMA and FDA. Ever since then to this day, it remains the world’s most popular impotence treatment in history.

The chemical structure

As mentioned, sildenafil belongs to the PDE-5 inhibitors class of pharmaceutical compounds. With chemical formula C22H30N6O4S, sildenafil is an organic compound2 with a characteristic piperazine ring methyl group, a property shared with vardenafil, the active ingredient of Viagra.

Sildenafil as PDE-5 inhibitor

PDE-5 inhibitors are unique in their mechanism of action. But, let’s not get ahead of ourselves. If we’re gonna talk about sildenafil as a PDE-5 inhibitor, we first need to take a look at what PDE-5 is? PDE-5 is a shorthand for phosphodiesterase enzyme type 5, a type of enzyme that exists naturally within the human body and which is tasked with driving the blood away from the penis after ejaculation. In healthy men, this is a very important function that is there to prevent injury to the penis or priapism.

On the other hand, in men struggling with erectile dysfunction, PDE-5 levels are usually heightened, causing the blood to withdraw from the penis too early, thus making a satisfying intercourse impossible. PDE-5 achieve this by degrading another important compound, cyclic guanosine monophosphate (cGMP) which is in turn tasked with widening the blood vessels in order to increase blood inflow and cause an erection. With too much PDE-5, there will be too little cGMP and erection will be impossible.

Sildenafil mitigates this problem by preventing PDE-5 enzymes from degrading cGMP. In this way, it contributes to the relaxation of smooth muscle tissue lining the blood vessels their subsequent widening. In this way, sildenafil works together with the body, by supporting its natural mechanism, making it a very non-intrusive ED solution.

How is it used?

Sildenafil is available in the tablet form only – both as branded and generic Viagra. The branded version is widely recognized, while the generic one is usually marketed simply under the name Sildenafil.  Both Viagra and generic version Sildenafil are available in the dosages of 25mg, 50mg and 100mg. The doctor will determine which one is the best for you, depending on the nature, root cause and severity of your condition.

Sildenafil tablets can be taken with or without food or water. However, it is important to note that if you take the medicine with too much oily or greasy food, the initial onset of the effects will take longer. However, if that isn’t the case, sildenafil will become active in roughly half an hour and its effects will last for up to 4 hours.

Can I get Sildenafil without prescription?

Both the generic and branded versions of sildenafil are prescription-only medicines and it is not possible to obtain them without prescription. Any vendors that might offer sildenafil-based medicine without prescription have either obtained it illegally or are selling counterfeit version. In either case, it can be very dangerous for your health, so it’s best to avoid those offers and get your sildenafil-based medicine the legal way.

You can do this by either visiting your doctor and asking for a prescription after detailed consultations, or if you’re the tech-savvy guy, you can get it through an online clinic. You will be asked to provide details of your condition and fill in a medical questionnaire. The doctor at the online clinic will then use those details in order to decide whether you’re suitable for treatment. If he approves sildenafil, the medicine will be delivered to your doorstep, as the part of the same service.

What are sildenafil side effects?

As with all prescription medicines, sildenafil also comes with potential side effects. While they are not that common, they do manifest in a small percentage of patients – enough to make it part of relevant knowledge when it comes to sildenafil treatment. The most common ones include:

  • Headache
  • Indigestion
  • Dizziness
  • Facial flushing
  • Muscle ache
  • Nausea
  • Vision problems

However, the biggest percentage of patients experiencing troubles with sildenafil treatment aren’t really experiencing side effects, but are rather reacting more strongly to its mechanism of action due to pre-existing condition. So, it’s important to note that you shouldn’t use sildenafil if:

  • You had a heart attack, stroke or life-threatening irregular heartbeat
  • You experienced chest pain or been diagnosed with angina
  • You have very high or very low blood pressure
  • You have kidney or liver diseases
  • You have priapism or sickle cell anaemia

References:

  1. Google Patents – Sildenafil
  2. Open Chemistry Database – Sildenafil