So far, only minor studies have been done where the new treatment principle has been tried. Earlier this year, German researchers published a non-blinded study of 112 patients with vascular impotence who were asked to either take sildenafil daily or use the drug as needed according to the normal procedure. After one year, the treatment was stopped and the participants had to refrain from taking the drug for four weeks 비아그라 판매.
At that time, 60 percent of the patients who received regular treatment had the ability to get an erection without having to use medication. The corresponding figure in the control group was 8 percent. The patients who received regular treatment and regained the ability to get an erection were followed up after another five months without access to medication. Then all but one still had the ability to get an erection. (Asian Journal of Andrology 2007; 9 (1): 123–41.)
Other smaller studies of regular dosing of sildenafil and tadalafil have shown similar lasting effects in different patient groups with erectile dysfunction. At the same time, a Finnish as yet unpublished double-blind study has shown that chronic administration of sildenafil did not produce lasting effects in patients after prostate cancer surgery 비아그라 판매.
- If this treatment principle is to be established, it must of course be evaluated according to the same evidence-based principles that apply to all new treatments in medicine. In addition to the pure patient benefit, however, there are several interesting scientific aspects in the new results, says Petter Hedlund, who works as a clinical pharmacologist at the university hospitals in Lund and Linköping on a daily basis 비아그라 판매.
- Erectile dysfunction is often the result of a general effect on the vascular system in patients with hypertension, diabetes and high blood fats. It has been speculated that this type of vasodilator could be used to improve vascular function in this patient group. According to this theory, one would first see an effect in small vessels, for example in the swelling bodies in the penis, which is supported by the current results, Petter Hedlund continues.
Agneta Bergqvist, medical advisor at Pfizer’s Swedish subsidiary that markets Viagra, thinks the current results are interesting. At the same time, she wants to downplay the possible benefits of regular dosing in erectile dysfunction.
- I think that most men think that medication works well when needed. Taking a tablet regularly for a long time may seem unnecessary to an otherwise healthy man. It may remind you that he still has an illness, she says.
Strengthens the signaling of nitric oxide
For the man to be able to get an erection, both sexual stimulation and that the blood supply to the penis is sufficient is required. About 30 times as much blood must flow to the corpora cavernosa of the penis compared to the normal state.
Sildenafil and similar substances act by inhibiting the enzyme phosphodiesterase type 5, PDE5. Thereby, the signaling of nitric oxide from the endothelial cells in the blood vessel wall is enhanced. Nitric oxide has a relaxing effect on the smooth muscles around the blood vessels and facilitates blood flow.
There are currently three PDE5 inhibitors approved for erectile dysfunction: sildenafil, tadalafil and vardenafil.