A sometimes tearful nurse testified Tuesday that her efforts to save Michael Jackson from the drug he craved for sleep were rebuffed by the star who insisted he needed the powerful anesthetic that eventually killed him.

Cherilyn Lee, a nurse practitioner who tried to shift Jackson to holistic sleep aids in the months before he died, said the singer told her Dipravan, a brand name for propofol, was the only thing that would knock him out and induce the sleep he needed.

He told Lee he had experienced the drug once during surgery.

Lee almost didn't testify. She sat down in the witness box then said she felt dizzy before starting to cry.

"This is just very sensitive for me," she explained.

Superior Court Judge Michael Pastor had her taken to another room to rest, and she returned 20 minute later saying she felt better. She became tearful again while testifying that she had warned Jackson not to take the drug.

Lee told of coming into Jackson's life at the beginning of 2009 and leaving just before Dr. Conrad Murray arrived. Murray has pleaded not guilty to involuntary manslaughter and is accused of giving Jackson a fatal dose of the drug Lee would not give him.

Lee recalled a meeting with the superstar at his rented mansion two months before his death.

"He was sitting very close to me," she said. "He looked at me and said, 'I have a lot of difficulty sleeping. I've tried a lot of things and I need something that will make me fall asleep right away. I need Dipravan."

Lee had never heard of the drug but did research and later told Jackson it was too dangerous to use in a home.

At one point she asked: "What if you didn't wake up?"

Jackson, however, was unswayed and adamant the drug would be safe if he had a doctor who could monitor him while he slept.

Prosecutors claim Murray abandoned Jackson after administering the fatal dose of propofol and failed to have proper life-saving and monitoring equipment on hand.

Lee was called to the stand by Murray's defense, but the impact of her testimony was mixed.

While she supported a defense theory that Jackson was doctor shopping in a desperate search for someone to give him propofol, a prosecutor seized on her warning to show Murray should have known the dangers too and refused the request by Jackson.

Under cross-examination by prosecutor David Walgren, Lee acknowledged a conversation with Jackson in which she told him: "No one who cared or had your best interest at heart would give you this."

She said her final refusal to provide the drug came on April 19, 2009, and she never saw Jackson again.

Another medical witness, Dr. Allan Metzger, testified Monday that Jackson also implored him to provide the anesthetic. Metzger also refused and instead gave the singer sleeping pills that had proven effective in the past.

Metzger saw Jackson just one day before Lee refused the request for drugs by the singer.

Attorneys for Murray, a Houston-based cardiologist, are trying to show that Jackson was a strong-willed celebrity who became the architect of his own demise when he insisted on getting the intravenous drug. They also alleged he gave himself the fatal dose after Murray left his bedroom.

Lee said she had treated Jackson for nutrition and energy issues as he prepared for his planned series of "This Is It" comeback concerts.

Lee was followed to the witness stand by Randy Phillips, president and CEO of concert promoter AEG Live who handled arrangements for Jackson's ill-fated concerts.

Judge Pastor blocked Murray's attorneys from asking Phillips about Jackson's contract with AEG for the shows.

Defense attorneys had wanted to introduce Jackson's contract to show that he would have owed $40 million to the promoter if the concerts were canceled. The lawyers said Jackson would be desperate to make sure the shows continued and needed sleep to get through his rehearsals.

Pastor said there was no evidence Jackson was concerned about the money and allowing testimony about the contract might confuse jurors.

"This is not a contractual dispute. This is a homicide case," Pastor said.

(Photo: AP Photo/Paul Buck)