Jackson probe focuses on powerful anesthetic

The emerging role of the anesthetic propofol in the death of Michael Jackson is bringing new attention to a powerful drug that is normally used only in hospitals, and has until now received little scrutiny from federal drug authorities because of its relatively low addiction risk.

Local and federal drug authorities Tuesday searched the Las Vegas home and office of Jackson's personal physician, Conrad Murray, as part of manslaughter investigations into the pop star's death. They didn't specify what they were looking for but a law enforcement official told the Associated Press that police have theorized that a dose of propofol that Dr. Murray administered as a sleep aid contributed to Jackson's death.

After propofol, known by its commercial name Diprivan, was found in Mr. Jackson's home following his death, federal drug authorities said they may re-designate the drug as a scheduled substance – a move that would tighten controls on how it is used and distributed.

Propofol is injected as an anesthetic for both minor and major surgeries, but its usage needs to be monitored and it should always be given in a hospital setting, say experts. There have bene only a few reported cases of abuse of the drug, mainly among anesthesiologists or medical professionals with access to the drug.

"To give this drug safely … they need to have certain monitors to watch that patient carefully," says Dr. David Kloth, an anesthesiologist and board member of the American Society of Interventional Pain Physicians (ASIPP).

The drug should never be used as a sleep aid, he says. "The fact that [Jackson] even asked for this drug would be a red flag that he has an addiction," says Dr. Kloth.

Patients on propofol can "have extremely variable responses to the drug and some patients can become completely anesthetized, including losing the ability to breathe," ASIPP said in a statement earlier this month.

Tuesday's search is the second time authorities have raided Murray's property. Last week, they searched his Houston office and storage unit. Murray is licensed to work in California, Nevada, and Texas and began working with Jackson in May to accompany him on his upcoming concert series in London.

The AP reported that Murray had admitted giving Jackson the anesthetic on the day of his death. He was with the pop star when he died and tried to resuscitate him.

Murray's lawyer said that the physician didn't "administer anything that should have killed Michael Jackson." Sources close to the investigation have also told the AP they are looking for other doctors who have given Jackson propofol.

Jackson reportedly used the drug as a sleep aid for the past two years.

Toxicology reports are expected to be released this week, and should shed more light on Jackson's death.

If it turns out that Murray did administer propofol to Jackson – and that was deemed a cause of death – he could face any number of penalties, says Kloth. Murray could lose his medical license or his ability to prescribe scheduled substances in addition to possible manslaughter charges.

"If this doctor put the IV in, he's going to be at least culpable," says Kloth.

But while propofol could be a cause of Jackson's death – the drug lowers heart rates and blood pressure – it could also be just one of many factors, especially if Jackson was taking other prescription medications at the same time.