Usually, or so my re-hab specialist tells me, neurolgical pain of this type
does not respond to narcotic analgesics, so why further increase your
discomfort (ie constipation) by trying them.
Amitriptyline is frequently suggested, but as you have found out there are
side effects that may very well prevent it's success.
Recently read an article suggesting an SSRI (like Prozac) and a much lower
dose of amitrptyline (in the neighbourhood of 10 to 50 mgm) has worked for
some patients.
Apparently the best drug for this type of neurological dysasthsesia is
carbamazepine (aka Tegretol). I was on this for several weeks and was
buidling up my dose and felt it was beginning to have some real success
until my MD had a fit when she found out my white cells were less than
3,000 --on the road to aplastic anemia and death --too bad for me --had to
stop.
There are now reports that Zoloft has been effective (another SSRI)
--and let's not forget some of the less "traditiional" therapies --these
have been around for thoudands of years and "modern medicine" is but 50-60
years old. Maybe the native North American Cultures were on to something
and Chinese medicine has been flourishing for longer!
Best for luck --keep trying --and if all else fails try vanilla ice cream
with hot fudge syrup and raspberry sauce --does nothing for the pain but
sure takes your mind off it for a second ;-)
bryan