What is the difference between anexia and norco (hydrocodone and acetaminophen)?

None: I have not heard of a medication called anexia. Norco (hydrocodone and acetaminophen) on the other hand is a synthetic narcotic with acetominophen used for pain relief.

Same: I assume you are asking about anesxia and norco (hydrocodone and acetaminophen). Both of them are combination of Acetaminophen and hydrocodone. Both of them come with different dosages.