Call an ambulance if he doesn't respond when your punchin him full force !
All this talk of slapping, punching, shouting at them, putting then into a cold bath/shower shit i hear year after year, is just that ! Shit, its useless, and wasting time, check breathing, and pulse, try get a response ( Without needing to linch your mate on the chin, then shouting in there ear, like what is that gonna do to ? reverse an od ? )
And OP - If no response, and has poor breathing / shallow breathing, long gaps between etc, And slow pulse, or no pulse rate, Then recovery position, and bite the bullet and Pick the phone up and get the emergancy services there.
I find this massively frustrating, Again people allways hanging on and on and, Im pretty sure if it was video'ed happening to YOU and you watched your mate / Smack aqaintenance whatever hanging around over you, And typing up threads on forums, and generaly wasting precious time, i bet you would be screaming at the tv screen saying hurry up, im fucking dying there FFS .
I can only hope this turned out ok as it wa a little while ago.