So-called adjuvant drugs also play a role
in the pharmacological management
of pain, especially that of neuropathic
or bone pain, which may not respond to
opioids. The term “adjuvant” is a
misnomer, as adjuvants may be the
only pain-relieving drugs prescribed for
patients in some cases, rather than
supplements to the main line of pharmacologic
therapy. Adjuvants for pain
include drugs of different classes
otherwise unrelated to each other, like
antidepressants and anticonvulsants
(for epilepsy), that have primarily been
used to treat other conditions but also
have analgesic effects. Doctors prescribe
antidepressants to patients in pain not
because they think their suffering is
“all in the head” but because pain relief
is a “side effect” of these drugs. An
older class called tricyclic antidepressants
have been in “off-label”
use for pain since the 1960s, meaning
that they are regularly prescribed for
pain even though the FDA has not
approved them for that purpose.
Fluoxetine (Prozac) has not been found
to affect pain, but a new antidepressant,
duloxetine (Cymbalta), is FDA-approved
to manage diabetic nerve pain.