Overview of Sildenafil Tablets
- Commercial (Revatio®): 20 mg
- Commercial (Viagra®): 100 mg
- Commercial (Generic): 20 mg, 25 mg, 50 mg, 100 mg
Sildenafil is a vasoactive drug that is extensively used to treat erectile dysfunction (impotence) in males and to alleviate symptoms in pulmonary arterial hypertension patients (PAH). Sildenafil enhances blood flow to specific regions of the body, including the penis, by lowering vascular resistance and relaxing muscles. Sildenafil is usually given 30 to 60 minutes before sexual intercourse, although sildenafil troche can be taken up to 10 minutes before.
Sildenafil is the most widely used erectile dysfunction medication. Sildenafil was created by a team of pharmaceutical chemists at Pfizer’s Kent, England laboratory who collaborated to synthesize sildenafil. The drug was initially developed to treat hypertension (a sign of ischemic heart disease) and chest pains caused by insufficient blood circulation to the heart. In 1991 and 1992, the medication was tested on males at Morriston Hospital in Swansea. Its clinical trials were overseen by Ian Osterloh, who suggested that the medication had little effect on treating angina but had a considerable effect on penile erections. Pfizer opted to market the medication as an erectile dysfunction treatment.
Sildenafil belongs to the class of drugs known as phosphodiesterase type 5 (PDE5) inhibitors. Sildenafil was originally designed as an antianginal medication, but it was discovered to be more successful in the treatment of erectile dysfunction (ED). Sildenafil is still being examined therapeutically to determine its utility in treating female sexual dysfunction, although preliminary trials have found that it performs similarly to placebo in women. In 21 clinical trials, sildenafil was tried in almost 4000 men with ED. These guys were 55 years old on average, and they had ED for an average of 5 years before entering the study. Sildenafil was effective in around 70% of individuals. In trials of male patients with psychogenic ED, response rates of 90% were achieved. Sildenafil may also be beneficial in male individuals suffering from ED caused by diabetes mellitus1 or pelvic fracture urethral rupture. 2 Sildenafil has been demonstrated to be efficacious and well tolerated in patients on multimodal antihypertensive regimens, with no added safety hazards. 3 Oral phosphodiesterase type 5 inhibitors (PDE5 inhibitors) are regarded first-line medication in ED treatment guidelines. 4 Sildenafil received final FDA approval for the treatment of ED in March 1998.
Studies conducted shortly after sildenafil was approved for ED revealed that it was useful in treating people with pulmonary arterial hypertension (PAH).
567 Sildenafil increased exercise capacity, mean pulmonary artery pressure, and other cardiac function measurements in PAH patients. Sildenafil is the first oral medicine licensed for the treatment of PAH in its early stages. Although preliminary data from 12 sickle cell anemia patients showed a reduction in PAH, a larger clinical trial (n = 134) investigating the use of sildenafil for pulmonary hypertension in adults with sickle cell anemia was halted early due to an increased risk of serious adverse effects, particularly sickle cell pain crises, when compared to placebo (38 percent vs. 8 percent , respectively). The cause of the increased risk of discomfort is unknown; nevertheless, patients in the earlier trial were aggressively treated with transfusions and hydroxyurea to control crises; the larger experiment did not offer any intervention for crises. Sildenafil has also been demonstrated to be effective in treating altitude sickness. 568 The FDA approved the oral formulation of sildenafil (Revatio) for the treatment of pulmonary arterial hypertension (PAH) in June 2005, and the injectable formulation in November 2009.
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