Ambien:
Perhaps the last word should go to Pat Flores, the mother of George Melendez, the 31-year-old coma patient who reassured his parents that he wasn't in pain after taking Ambien, as zolpidem is known in the US. He was starved of oxygen when his car overturned and he landed face down in a garden pond near his home in Houston, Texas, in 1998. "The doctors said he was clinically dead - one said he was a vegetable," says Pat. "After three weeks he suffered multi-organ failure and they said his body would ultimately succumb. They said he would never regain consciousness."He survived and four years later, while visiting a clinic, Pat gave him a sleeping pill because his constant moaning was keeping her and her husband, Del, awake in their shared hotel room. "After 10 to 15 minutes I noticed there was no sound and I looked over," she recalls. "Instead of finding him asleep, there he was, wide awake, looking at his surroundings. I said, 'George', and he said, 'What?' We sat up for two hours asking him questions and he answered all of them. His improvements have continued and we talk every day. He has a terrific sense of humour and he carries on running jokes from the day before.
Ambien, Patrick Kennedy, Vegetative State.
an article on this case from July - http://abcnews.go.com/GMA/OnCall/story?id=2154940&page=1
"He can respond to his parents by either shaking his head yes or no and sometimes even speaks."
Somewhat different from a two hour running conversation ...
Ah, Ambien ... there is also that "Ambien effect" that, when not bringing forth legislators for 3 AM roll calls, does have some people up and functioning while still asleep.