Edex is another name for alprostadil also known as prostaglandin. It is marketed in injectable form as Caverject. It also has a pellet (suppositary) form called Muse. Many users find that they get serious pain and have stopped using it.
Injections work well for most men (Me too). I tried Caverject and then went to BIMIX which does not have the alprostadil, so there is no pain at all. Some men now use TRIMIX which includes a smaller portion of the alprostadil. The other two parts of bimix/trimix are papavarine and phentolomine.
Good luck I have been using bimix successfully for 4 years now.