Medical treatment for this octo bite is the same as eating blowfish. It is tetrodotoxin. It stop brain signals from reaching your lung to let you breath. It is similar if not the same as polytoxin. All you have to do is put yourself on a artificial breathing machine and after 24 hours you should be fine.
Just a technical correction. It doesnt so much stop the signals travelling from the brain but acts at the neuromuscular junction ( I'm in the middle of Neuroscience I right now and the texts/doc's love this one ).
BTW - how did that fight end?