TRPV1 agonist? 

It makes no sense. TRPV1 activation causes pain or heat sensation. Capsaicine is known to activate the receptor, and that's what makes chili pungent. If one of the reasons for AM404 being an analgetic was TRPV1 activation, it would have to be the opposite to that of capsaicine. The only wat in which TRPV1 agonism would decrease pain is that a prolonged exposure to high doses of the agonist decreases the sensitivity, which is the case in any type of receptor activation, but this would mean that AM404 is no more an analgetic than capsaicine or any other source of pain... and the relief would come after a period of pain actually getting worse.

Can anyone explain all this?