Michael Jackson had been using Propofol since 1999, according to his former personal assistant. The 'Billie Jean singer died in 2009 from acute intoxication of the anesthetic - which is usually reserved for use in hospitals - and his one-time aide Frank Cascio claims he had been taking the drug for a decade. Writing in his new memoir, 'My Friend Michael: An Ordinary Friendship with an Extraordinary Man, Frank claims he believes the pop superstar first started using painkiller Demerol after burning his head while filming a TV commercial for Pepsi in 1984 and that he first noticed him using it on his 'Dangerous World Tour in 1993, which he believed was to treat a skin disease. Frank - who was a friend of Michael from the age of five - claims his drug use had escalated so much that by 1999 he had started to take Propofol after injuring himself in a fall from a stage in Munich, Germany. EPS