Searches run: I've tried googling for "drugs injected act instantly" and "drug inject knock out" and so forth, but none of these searches really bore any fruits. I've leafed through Wikipedia, too, but I don't really know what to look for exactly. I found a link to an article to Straight Dope, but that only covered whether it's possible at all to knock someone out quickly which I know it can from experience ^^;.
My character is a doctor who is allowed to practice medicine in the US. In my story, he needs to knock out a character who is a friend which means that he'll be able to get close to this person and doesn't need to overpower him or anything. I want a fast acting drug that will manage to knock a grown man out instantly. Basically like chloroform is usually used in fiction. I seem to remember reading somewhere that chloroform doesn't actually work like that.
Right now I'm thinking along the lines of injecting something either into the arm or maybe intravenously into the jugular or so. To have it fast acting it would have to be IV, no? Would that work, if we simply assume he manages to administer it in this way. Inhaling would be okay, too, if that exists. Since the character is a doctor and doesn't mind forging signatures or so in case he wouldn't be able to fill the script for himself, it should be possible for him to grab the substance from a pharmacy, wouldn't he? I'm willing to bend reality to a certain extent to make it work. I just want a drug and a way to administer it that would work. I hate dicking around with vague terms that shows I have no idea what kind of drug he's actually using.
Thanks in advance!