Now days there are three oral drug medications that has been approved for the treatment of erectile dysfunction:
1. Sildenafil citrate
Well known as Viagra, available on 1998, become as first and prime treatment to impotence. Developed and being marketed by Pfizer. Other trade name is Revatio.
Treatment for impotence that is available by 2003 and it’s famous under trade name Levitra world-wide and Vivanza in Italy. The pill was developped and marketed by Bayer, GSK and SP.
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| Levitra |
Third drug that has been used for treating erectile problem by the end of 2003. World-wide known as Cialis and Tadacip in India. It has been developed and marketed by JV Lilly ICOS, LLC.
All three belong to a class of drugs called selective enzyme inhibitors. Sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) block the enzyme phosphodiesterase type 5 (PDE5), so called PDE5 inhibitor. Blocking this enzyme helps maintain levels of cyclic Guanosine MonoPhosphate (cGMP), a chemical produced in the penis during sexual arousal. Balanced levels of cGMP causes the smooth muscles tissues of the penis to relax and increases blood flow.
PDE5 inhibitors (Viagra, Cialis and Levitra) are a good choice for men at any age and in any ethnic group who are in good health and who do not have conditions that preclude taking them.
Effectiveness of PDE5 Inhibitors.
• Tadalafil (Cialis). It appears to take effect in 15 to 30 minutes after consumption. It is the only oral ED treatment shown to improve erectile dysfunction for up to 36 hours in most men. A randomized study of 2,102 men in the British Journal of Urology found that nearly two-thirds of men reported successful intercourse attempts 24 to 36 hours after taking the drug.
• Sildenafil (Viagra). Studies indicate that overall, sildenafil may help more than 70% of patients achieve sexual function, with results depending on indication conditions.
• Vardenafil (Levitra). Extensive clinical studies have shown that vardenafil improves erectile dysfunction in up to 85% of men with the condition. It also has shown to be work well in patients with diabetes and in those who have had a radical prostatectomy.
Studies indicate that PDE5 inhibitors are safe and effective for many men whose erectile dysfunction is related to the following conditions:
• Hormonal problems or psychologically induced impotence. These men achieve the highest success rates (80 - 100%).
• Stable heart disease. However, PDE5 inhibitors should not be used by men who take nitrate drugs for chest pain or heart problems.
• Mild to moderate congestive heart failure. (A randomized study in the Archives of Internal Medicine found that men with moderate congestive heart failure and ED can safely use sildenafil to improve their sexual function and overall quality of life, provided the men are not taking nitrates for their heart condition. In addition to exhibiting improvements in ED, the study participants taking Viagra also showed higher scores on depression screening exams. Other research has also suggested that Viagra is safe for this group of men and may even improve exercise capability.
• Controlled diabetes (type 1 or 2). Diabetes has been associated with a lower than average response to Viagra. Still, in a 2002 study over half of patients with type 2 diabetes achieved at least one successful sexual event.
• Kidney conditions, including those that require chronic dialysis and kidney transplantation.
• Parkinson's disease. There is even some evidence that sildenafil may even have properties that improve depression and help brain functions (attention, memory).
• Depression. PDE5 inhibitors may help men who take antidepressant drugs that cause sexual dysfunction, notably the popular serotonin reuptake inhibitors, such as Prozac.
review from healthcentral.com
Youtube on PDE5 Inhibitor
