April 18, 2024
Sildenafil Drug

The Comprehensive Guide To Sildenafil Uses, Mechanism Of Action, Side Effects, And Considerations

Sildenafil is a drug used to treat erectile dysfunction and pulmonary arterial hypertension. With the commercial name Viagra, it is one of the most known drugs in the world.

Uses of Sildenafil

The primary use of sildenafil is for treating erectile dysfunction in men. Erectile dysfunction, also known as impotence, is the inability to develop or maintain an erection of the penis during sexual activity. Sildenafil works by enhancing the effects of nitric oxide, a natural chemical that relaxes smooth muscles and increases blood flow to the penis. By facilitating erection, sildenafil improves the patient’s ability to engage in sexual intercourse.

Pulmonary Hypertension

Besides erectile dysfunction, Sildenafil Drug is also approved for treating pulmonary arterial hypertension. Pulmonary arterial hypertension is high blood pressure that affects the arteries in the lungs and the right side of the heart. In such patients, sildenafil works by relaxing the blood vessels in the lungs to improve blood flow and reduce strain on the heart. This improves the patient’s ability to do physical activities and reduces symptoms related to pulmonary hypertension.

Mechanism of Action

As mentioned earlier, sildenafil works by enhancing the effects of nitric oxide, a chemical messenger involved in erectile response. During sexual stimulation, nitric oxide is released in the penis which triggers the production of another chemical called cyclic guanosine monophosphate (cGMP). This cGMP production leads to smooth muscle relaxation in the corpus cavernosum and allows inflow of blood.

Sildenafil inhibits an enzyme called phosphodiesterase type-5 (PDE5) which is responsible for degradation of cGMP. By inhibiting PDE5, sildenafil increases cGMP levels in the corpus cavernosum, thus improving erectile function. In the lungs, it works similarly to relax smooth muscles and dilate blood vessels. This mechanism of action specifically targets the erection pathway in penile tissues as well as pulmonary arteries.

Side Effects of Sildenafil

Like all medications, sildenafil also comes with some potential side effects:

Headache is the most commonly reported side effect. It occurs in about 15% of patients.
Flushing of face and upset stomach have also been seen in few patients.
Temporary changes in vision such as increased light sensitivity, blurred vision and eyesight changes are seen rarely.
Back pain, muscle aches, nasal congestion are some other reported side effects.
Combination with nitrates like nitroglycerin may lower blood pressure dangerously.
Rarely, sildenafil may cause prolonged erections over 4 hours known as priapism.
However, most side effects are mild to moderate in nature. Proper medical supervision is important for people with severe cardiovascular disease.

Important Considerations

There are a few important factors to consider before taking sildenafil:
Inform your doctor about medical conditions like heart disease, stroke, high/low blood pressure. Sildenafil may not be suitable.
Give at least 24 hours gap if taking short-acting nitrate medications which are commonly used for chest pain.
Take sildenafil one hour before sex with or without food except fatty meals which can delay absorption.
Drinking alcohol in excess can lower blood pressure increasing hypotension risk with sildenafil.
Effects of sildenafil may last 4-5 hours. Seek help if erection persists more than 4 hours.
Avoid grapefruit and grapefruit juice which can interact with sildenafil increasing its effects.
Tell your doctor if other medications are being used as there may be interactions.

Sildenafil is a highly effective and relatively safe treatment for ED and PH when taken as prescribed under medical supervision considering above points. It has revolutionized treatment for ED globally.

New Developments

As the patent for sildenafil expired, several generic versions called sildenafil citrate have emerged in the market at affordable costs. Additionally, research is also ongoing to develop newer PDE5 inhibitors and drug delivery methods for treating erectile dysfunction. Some of the new drugs in various stages of development and approval include:

Tadalafil (Cialis): Longer duration of action up to 36 hours. Approved for use.

Vardenafil (Levitra): Rapid absorption, suitable for as needed use. Approved.

Avanafil (Stendra): Rapid onset of action within 15 minutes. Approved.

Mirodenafil (Mvix): Newly approved in South Korea. Research ongoing in other countries.

Udenafil (Zydena): Available in South Korea and Philippines.

Lodenafil carbonate (Helleva): Under phase 3 trials.

About sildenafil drug, the active ingredient in Viagra which is one of the most known drugs globally. Sildenafil revolutionized ED treatment and has good safety profile when used judiciously. New versions and research in novel PDE5 inhibitors holds promise to further enhance treatment outcomes. Overall, sildenafil remains the gold standard first line treatment for ED and PH approved for use by healthcare professionals worldwide.

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