I had major discomfort with the Caverject, and the tri-mix worked, but
there was still discomfort and sensitivity which detracted from the
enjoyment.  The ED specialist then put me on bi-mix, no prostaglandin, and
there was no discomfort at all.  More like a normal erection.  I used the
same dose as what I used with the tri-mix, but the erection was not firm and
penetration was not achieved.  The doctor had told me that I could use a
higher dose, so I will try that next.

 As stated previously, do not be afraid of the injection itself.  I can
feel the needle going in, but there is no pain.  I use an insulin syringe,
so the needle is very fine and short.  There is no chance of going in too
far.  Be sure to make the injection on the side of the penis about midway
along the length and alternate sides.  Do not try to make the injection on
the top or bottom of the penis (or in the head).  You want to avoid hitting
veins or nerves.  The idea is to get the drug injected into the spongy area
that gets engorged with blood and that is what produces the erection.  At
least that is what the doc explained to me.  The point is, if you have
impotence, do not shy away from the injections as an alternative treatment
due to fear of the needle.

Good luck.