(Alprostadil is also referred to as prostaglandin E1. In powdered variety, it could be referred to as CaverJect or Edex.) Papaverine in addition phentolamine additionally alprostadil (Tri-Mix) is the most potent alternative. It needs refrigeration and it has the same side effects as papaverine and alprostadil. Quad-Mix, a combination of Tri-Combine