Erectile dysfunction or impotence is a common sexual problem among men worldwide. For years, there was no effective treatment available for this condition until the drug sildenafil was discovered and approved for use. Since then, sildenafil revolutionized the treatment of ED.

Discovery and Approval

In the late 1980s, scientists at Pfizer were conducting research on a drug called  Sildenafil Drug to treat chest pain and hypertension. During early clinical trials, they found that the drug had little effect on angina but seemed to have an interesting side effect – it helped treat erectile dysfunction in men. Pfizer saw the potential and refined sildenafil into a treatment specifically for ED.

In 1998, sildenafil was approved by the US FDA under the brand name Viagra for treatment of erectile dysfunction. It became the first effective oral treatment approved for this condition and was a massive commercial success. Its approval and effectiveness marked a major step forward in ED treatment and legitimized the condition as a medical problem with a real solution.

Mechanism of Action

Sildenafil works by inhibiting an enzyme called phosphodiesterase type 5 (PDE5). The enzyme is found in the smooth muscle cells of the corpus cavernosum, the two spongy tissues within the penis involved in erection. During sexual stimulation, nitric oxide is released in these tissues which triggers the production of an intracellular messenger called cyclic GMP or cGMP. This results in relaxation of the smooth muscle cells and dilation of the blood vessels, causing an erection.

PDE5 breaks down cGMP and prevents this process. Sildenafil inhibits the action of PDE5 and allows cGMP to accumulate, resulting in improved blood flow to the penis and allowing a man to get and maintain an erection. This makes it possible for men with erectile issues to respond sexually to stimulation.

Effectiveness and Usage

Various clinical studies have proven sildenafil to be a highly effective treatment for ED. When taken as prescribed, sildenafil helps over 80% of men achieve and sustain erections suitable for sexual intercourse. However, it will only work if there is sexual stimulation.

Sildenafil comes as a tablet that is usually taken 30-60 minutes before sexual activity. The starting recommended dosage is 50mg and it can be increased up to 100mg or decreased to 25mg based on effectiveness and tolerability. Its effects typically last 4-6 hours but can vary between men. It is recommended not to take more than one dose in a 24-hour period.

Sildenafil is generally well-tolerated by most men. Some of the common side effects reported include headaches, facial flushing, indigestion and congestion. However, serious side effects are rare. It should not be combined with certain drugs like nitrates and recreational drugs. Also, men taking alpha-blockers need to be monitored closely when starting sildenafil.

Access and Competition

When it was first approved, Viagra had worldwide patent protection and Pfizer dominated the erectile dysfunction market. However, generic versions of sildenafil became available in many countries after Pfizer’s patent expired in 2013. This allowed other pharmaceutical companies to enter the market, significantly driving down prices.

Now sildenafil is widely available globally both as a prescription drug and over-the-counter in many countries. Competition has made it far more affordable with prices dropping up to 90% compared to branded Viagra. Doctors often prescribe generic sildenafil instead of original Viagra for cost-effectiveness. This has made ED treatment more accessible worldwide.

However, Pfizer remains a leader with its branded Viagra and has come up with newer formulations like Viagra Connect which can be purchased over-the-counter without a prescription in select countries. Other approved ED drugs like Cialis and Levitra have also entered the market adding more treatment options.

Future Therapy Options

Though sildenafil revolutionized ED treatment, research continues to explore other potential treatments. Oral therapies in development aim for longer duration of action than sildenafil without decreasing effectiveness over time. Other novel approaches being studied include topical creams, patches and injections directly into the penis, bypassing digestion. Gene therapy is another promising area to potentially cure ED permanently.

Scientists are also looking at new drug targets beyond PDE5 inhibition. Substances that can promote nitric oxide signaling or regulate penile nerve function could yield therapies with novel mechanisms. In addition, stem cell-based therapies may someday help regenerate damaged penile tissues involved in erectile function. The future still holds great potential to enhance ED treatment from where sildenafil has set the foundation.

Discovered serendipitously, sildenafil has become one of the most commercially successful drugs ever. As the first effective oral treatment for erectile dysfunction, it transformed millions of men’s lives and revolutionized how the condition is viewed and managed. Going generic has made sildenafil accessible to more worldwide at lowered costs. Future therapies may build upon this blockbuster’s achievements but sildenafil and its discovery will always remain a true milestone in modern medicine’s war on impotence.

*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it.