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...