Results of Michael Jackson’s toxicology tests have not yet been released, but suspicions have centered on the powerful anesthetic and sedative drug propofol, also known by the brand name Diprivan. It was reportedly found in Jackson’s house, and a nurse who worked with him said he begged for propofol to help him sleep. 

Now, some lots of propofol are being recalled for contamination.

Last night, the Centers for Disease Control and the Food and Drug Administration advised clinicians immediately to stop using propofol from two lots found to be tainted with elevated levels of endotoxin, a toxin made by bacteria. Regulators said Teva Pharmaceuticals, the manufacturer, had begun a voluntary recall of the lots.

Several drug companies are licensed to produce propofol in the U.S.

FDA spokesperson Karen Riley said the agency’s investigators were currently at the Irvine, Calif., plant where the tainted propofol was manufactured.  She was unaware of the size of the lots. At least 39 patients had been affected in Florida, Arizona and Missouri since May, Riley said.

The CDC’s lead investigator on the case, Dr. Arjun Srinivasan, said clinicians across the country are being urged to check their inventories because the product was distributed nationally.

Srinivasan said the agency received an initial report about the drug from an outpatient surgery center on June 29. The Missouri center had 20 cases of patients who developed high fevers and muscle aches shortly after receiving the drug.

The CDC put out word to the FDA, state and local health agencies and providers. That quickly led to discovery of the tainted propofol and Monday’s warning, Srinivasan said.

All patients known to have been affected have recovered, he said. However, at high doses, endotoxins can cause a sequence of reactions, beginning with fever and progressing to shock and death.

There is no confirmation on whether Jackson received propofol before his death or whether, if so, the drugs reportedly found at his home came from one of the two tainted lots.

Teva Pharmaceuticals had no immediate details.

"Everybody seemed to find out about this before we did," a Teva customer service representative said today at noon.  "We just found out about this an hour ago."  She said company officials were meeting about the recall and would have a statement later today.

The drug is typically used to anesthetize patients for procedures such as colonoscopies.  It can be dangerous if it is not administered carefully in a medical setting, and should not be used as a sleep aid. 

Researcher Lisa Schwartz contributed research to this article.