An overview of Sildenafil citrate
Sildenafil citrate is the most commonly prescribed medicine for erectile dysfunction. It marketed under the brand name “Viagra”. It is also used for treating pulmonary hypertension. Sildenafil 20mg marketed under the trade name Revatio is used for treating pulmonary hypertension. Generic versions of sildenafil citrate are also available which have lower cost than the branded version.
History of Sildenafil Citrate
- Sildenafil citrate was synthesized by a group of research scientists at Pfizer.
- It was primarily studied for treating hypertension (high blood pressure) and angina pectoris (a symptom of ischemic heart disease).
- Sildenafil citrate was the first effective oral medicine approved for the treatment of erectile dysfunction in men by Food and Drug Administration (FDA) in the year 1998.
- It is a powerful cGMP-specific phosphodiesterase type 5 (PDE-5) inhibitor.
- It is a non-habit forming medicine.
What is pulmonary hypertension?
Pulmonary hypertension is a disorder affecting the blood vessels in the lungs and the right side of the heart.
What happens in pulmonary hypertension?
Small arteries in the lungs called as the pulmonary arterioles and capillaries become narrow, are blocked or are damaged. This is the reason why the blood flows through your lungs under pressure, thus increasing the pressure inside the lung’s arteries. As the pressure increases, the heart’s lower right chamber (right ventricle) works harder to pump blood through your lungs, ultimately weakening your heart muscle and causing a heart failure.
Symptoms of pulmonary hypertension include:
- Shortness of breath in the start while exercising and eventually while at rest
- Faintness
- Lightheadedness
- Chest pain
- Swelling of ankles and legs
- Ascites (Abnormal accumulation of fluid in stomach)
- Bluish colored lips and skin (cyanosis)
- Arrhythmia or heart palpitations or irregular heartbeats.
Use of Sildenafil Citrate for treatment of pulmonary hypertension
As phosphodiesterase enzyme is present in abundance in the blood vessels in the lungs, the phosphodiesterase inhibitors such as Sildenafil citrate (Revatio) can be used for treating pulmonary hypertension.
Sildenafil citrate inhibits phosphodiesterase type 5, an enzyme that produces degradation of cyclic guanosine monophosphate (cGMP), thereby increasing the concentration of the cyclic guanosine monophosphate, which causes relaxation of smooth muscles in the lungs and dilation of blood vessels in lungs. The dilated blood vessels improve the blood flow to the lungs causing reduction in the blood pressure.
According to the scientific reports, Sildenafil increases exercise capacity and blood flow in patients with symptomatic pulmonary arterial hypertension.
Common side effects
The side effects observed after taking Sildenafil citrate are minimal and are mild in nature. They often subside after subside after the drug eliminates from the body. The commonly observed side effects include nausea, vomiting, abdominal pain and nasal congestion.