Feasible to dose naloxone one's self on solo opiate OD?

[Beltane]

SWIM has played around a tiny bit w/ H and the people at the NE gave him a bottle of Noloxone just in case. He's loaded a 1CC syringe and keeps it handy in case he ever takes too much or gets caught doing too much of too strong a new batch.

Never bothered to ask tho, is it likely that SWIM would be able to put a loaded 1 CC of noloxone to good use if he were headed toward OD? Or would he be too far gone? SWIM has barely got around to recognizing the signs of H let alone an OD dose. What signs might one be on the lookout for as evidence of a possible self overdose?

Thanks-

- Beltane