Officials have not yet determined the cause of death for pop star Michael Jackson, but a disturbing picture continues to emerge of the amount and range of strong prescription medications the singer was allegedly taking at or near the time of his death last Thursday.

TMZ reported that the drug Propofol was found at Jackson's rented Los Angeles home after his death. The very potent drug, also known as Diprivan, is administered intravenously as a general anesthetic used to sedate patients for surgery and is only available to medical personnel.

"This is only meant for use in anesthesia and [administering it as a sleep aid] it's like giving someone chemotherapy so they don't have to shave their head," said veteran anesthesiologist Dr. John F. Dombrowski, who has not treated Jackson and has no information about the case, but has used Propofol often in his practice. "It's one purpose is as an anesthetic, to induce that sleepy feeling and when I run it as an IV drip I can keep you asleep and when I turn it off you are quickly awake. It works in 30 seconds or so and it is out of your system quickly when I turn it off."

Dr. Dombrowski said the drug is so powerful that it is critical to have someone in attendance who has the ability to rescue you should your breathing cease or some other critical failure occur, which is why the drug is only used in operating rooms and in doctor's offices where providers are on hand to support patients and intervene should something go wrong. "It is never used outside a medical setting during a procedure," he said. "And it is never used as a sleeping aid. I've never heard of that in my 16 years of practice."

Registered nurse Cherilyn Lee told The Associated Press that Jackson repeatedly begged her for the drug to help him with insomnia related to anxiety over his upcoming 50-date residency at the O2 Arena in London. Lee said she declined his requests for the drug, which TMZ said could have played a part in the singer's death. According to Lee, a member of Jackson's staff called her in a panic on June 21 pleading with her to help him after what appeared to be an adverse drug reaction. "At that point, I knew that someone had given him something that hit the central nervous system," she said of the singer's complaints that half of his body felt hot and half felt cold.

A spokesperson for the drug's provider, APP Pharmaceuticals, confirmed that it is only available to medical professionals. The widely used drug is used primarily for outpatient surgical procedures because it is very fast acting, typically knocking the patient out within 30 seconds. As described by Lee to the AP, Jackson complained of hot/cold sensations and Propofol is sometimes known to create a painful burning sensation, which is often alleviated by the use of the drug Lidocaine, which TMZ reported was also found near Jackson's body.

A source told the site that the drug is so inappropriate for home use that if a doctor supplied it for Jackson or helped inject him with it and it caused his death, he or she could be prosecuted for manslaughter.

Dombrowski said that Jackson, who was reportedly on a number of different strong pain medications at the time of his death and who was alleged to have struggled with an addiction to prescription medication, likely built up a tolerance to those drugs over the years. "You not only build up a tolerance, but these drugs can also mess with your sleep cycle and so you want to be sedated, you want that feeling of being out that patients who abuse these medications like," he explained. "After a while, you are no longer getting out like you want to be, so you need an anesthetic and a cardiologist or nurse who might know of these drugs might make the leap that they could be used to help someone sleep. But again, that is way, way out there."

For complete coverage of the life, career and passing of the legendary entertainer, visit "Michael Jackson Remembered."

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