Posted by stjames on July 23, 2001, at 0:14:35
In reply to Why codeine but not Ultram? - Elizabeth, posted by Zo on July 22, 2001, at 17:20:44
> Why the heck would 1/4 an ancient tylenol and codeine tab cut a spiral down of depression. .. and not Ultram?
james here....They are not really the same class of meds. Ultram is different:
ULTRAM is a centrally acting synthetic analgesic compound. Although its mode of action is not completely understood, from animal
tests, at least two complementary mechanisms appear applicable: binding of parent and M1 metabolite to µ-opioid receptors and
weak inhibition of reuptake of norepinephrine and serotonin. Opioid activity is due to both low affinity binding of the parent compound
and higher affinity binding of the O-demethylated metabolite M1 to µ-opioid receptors. In animal models, M1 is up to 6 times
more potent than tramadol in producing analgesia and 200 times more potent in µ-opioid binding. Tramadol-induced analgesia is
only partially antagonized by the opiate antagonist naloxone in several animal tests. The relative contribution of both tramadol and
M1 to human analgesia is dependent upon the plasma concentrations of each compound
poster:stjames
thread:71405
URL: http://www.dr-bob.org/babble/20010720/msgs/71464.html