After a six-hour autopsy and more than six weeks of investigation, officials say that the death of Anna Nicole Smith was due to the combined effects of nine different prescription drugs.
Dr. Joshua Perper, Broward County chief medical examiner, said at a press conference Monday that each of the drugs found in Smith's body were present in levels lower than what would normally lead to overdose.
But, he added, the combination of the medications led to a toxic, and ultimately lethal, effect.
The 39-year-old personality was found dead on Thursday, Feb. 8, in her hotel room at the Seminole Hard Rock Hotel and Casino. Police officials say that with the disclosure of the autopsy report, suicide and homicide can now be ruled out.
"We are convinced, based on an extensive view of the evidence, that this case is an accidental overdose with no other criminal elements present," said Seminole Police Chief Charlie Tiger at the press conference.
However, pathology experts said the array of drugs that Smith had been prescribed -- including an antiquated sleeping drug and three antidepressants with similar actions -- should be further scrutinized in order to learn more about how such an overdose was allowed to occur.
Perper mentioned that a total of nine prescription drugs were found in Smith's system; however, during the press conference he also listed several other drugs, as well as one nonprescription drug and a number of supplements, which were identified during the autopsy.
This suggests that Smith had been taking or had recently taken more than a dozen different medications at the time of her death.
Perper said chloral hydrate, a sleeping medication, was the drug which "tipped the balance" and most directly led to Smith's demise.
He added that three prescription drugs used for treatment of anxiety and depression likely contributed to the intoxication that led to her death. These were clonapine (commonly known as Clonazepam or Klonopin), diazepam (commonly known as Valium) and lorazepam (commonly known as Atavan).
He said Smith had been suffering from severe depression, as well as the stress associated with a number of lawsuits -- a likely reason for the medications.
But Dr. Jeffrey Barnard, professor of pathology at UT Southwestern Medical Center and chief medical examiner for Dallas County, Texas, said all of these drugs essentially have the same function.
In addition, he said, these drugs depress the respiratory system -- a characteristic shared by chloral hydrate and some of the other drugs found in Smith's system.
"Alone, each the drugs in that combination do not have to be in a lethal concentration to be deadly if the combination of their effects are cumulative," Barnard said.
Perper added that there was also evidence of a number of other drugs in her system, including the antihistamine Benadryl, the flu medication Tamiflu, a muscle relaxant and the drug Topamax, which is used to control seizures, migraines and weight gain.
Atropine was found in Smith's system, although this was likely introduced by emergency medical personnel who treated her at the scene.
Smith is also known to have been taking the antibiotic Cipro, methadone for pain control, acetaminophen and a number of "anti-aging" supplements including human growth hormone, vitamin B12 and immunoglobulin.