Technically, no. Morphine is an opioid, while tramadol is an
"opioid like substance".
For all intents and purposes - yes. Both act on the same
receptor, the opioid receptor (mu), both act as painkillers by
identical means on the opioid receptor and both are prescribed as
painkillers.
The difference being that morphine acts only on the opioid mu
receptor (with minor affinity to the other opioid receptors) while
tramadol acts on the opioid mu receptor AND as a serotonin and
norepinephrine reuptake inhibitor producing its unique side effect
profile among opioid like painkillers.
Finally, in practice while morphine is a much stronger
painkiller (due to its affinity rather than its mechanism) it has
the standard opioid side effects of drowsiness, constipation, etc.
Tramadol, on the other hand, reduces pain by both the opioid
component and the serotonin-increasing component. This gives it
approximately twice the potency it "should" have if looking at only
the opioid component - the drowsiness, constipation and addiction
aspects. Further, the serotonin can promote wakefulness (though not
for everyone) countering some of the negative opioid side effects.
This sometimes makes it a preferable to the codeine/hydrocodone
type drugs, although this usually is the patients choice.
Source - long term pain management patient and medical doctor,
F2.
