This include penile injections before sexual intercourse. Shots are not only painful but expensive and have potential side effects. One of which is prolonged erection. Not only is this quite uncomfortable but it could require another injection to reverse the first. A more permanent solution is to have a penile implant.
Implants can be semi-rigid or inflatable.
Finally you can choose external vacuum pump therapy. The penis is inserted into a plastic cylinder to create a partial vacuum that encourages increased blood flow into the penis. A tension ring at the base prevents the blood from draining. For proper counseling about these alternatives I recommend you see a urologist specializing in male impotency problems. It is no wonder, after reviewing these alternatives, that man has sought the assistance of mother nature throughout the centuries in his search for sexual bliss.