(Alprostadil is often known as prostaglandin E1. In powdered variety, it might be identified as CaverJect or Edex.) Papaverine in addition phentolamine in addition alprostadil (Tri-Mix) is easily the most powerful alternative. It requires refrigeration and it has the exact same side effects as papaverine and alprostadil. Quad-Mix, a mix of Tri-Mix