A personal assistant turned personal manager to Michael Jackson said the King of Pop had been taking propofol as early as 1999, and that the singer was drugged up ahead of his 2001 30th anniversary concerts. Frank Cascio, who became a family friend to Jackson at age 5 and eventually one of the singer's closest friends and employees, writes in a new book that he first noticed Jackson taking the drug Demerol while accompanying the singer on his “Dangerous” tour in 1993. He writes in his new book, “My Friend Michael: An Ordinary Friendship with an Extraordinary Man,” that Jackson started the first of two anniversary shows in 2001 an hour late as a result of being drugged up in his dressing room. “...My naive belief that Michael wouldn't let his medicine interfere with the show blew up in my face,” Cascio writes. “I can't begin to describe my disappointment and panic at this moment.” The Associated Press purchased an advance copy of the book, which is set for release Nov. 15 by William Morrow, an imprint of News Corp.'s HarperCollins. Cascio became a friend of Jackson's after his father introduced him to the singer; Cascio's father worked at the Hemsley Palace in Manhattan, managing the hotel's towers and suites, where Jackson stayed. Following that, a five-year-old Cascio and his younger brother Eddie, spent time with Jackson at his Neverland Ranch. He says Jackson was first introduced to Demerol in 1984 when he burned his head during a Pepsi commercial shoot, and Cascio writes that he first noticed Jackson using the medicine on his “Dangerous” tour.