On the bright side, you were well enough to ratch round scrapyards the following day.
Have you still got both your Kidneys?
All joking aside, you were lucky your mates were keeping an eye out for you. My mates Girlfriend was spiked in a club, and passed out in the toilets. Come checking out time, her mates realised she wasn't there, and sent a bouncer in to check. There she was, on the floor of the cubicle, but otherwise unharmed.
I never leave a drink unattended in clubs etc. (Well, if I do, I never finish it)