lethal combination of drugs killed Anna Nicole Smith's son

Pathologist Cyril Wecht has revealed to People magazine that Anna Nicole Smith's 20-year-old son Daniel died of a lethal combination of methadone, Zoloft and Lexapro.
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Wecht said the drugs caused the cardiac dysrhythmia that led to Daniel's death. Wecht got the toxicology results from National Medical Services in Willow Grove, Pa., today.

Daniel Smith died in his mother's hospital room Sept. 10 while visiting her in the Bahamas three days after she gave birth to a baby girl named Dannielynn Hope.

On Sept. 9, Daniel Smith arrived in Nassau to see his mother, with whom he'd always been extremely close. The family, including his newborn sister, spent time bonding in the hospital room that night. Daniel was seen tending to his mother around 6:20 a.m. on Sept. 10 – but at 9:38 a.m. that day Anna Nicole woke up to find her son unresponsive.

Doctors were immediately summoned and tried for 22 minutes to revive Daniel without success. He was pronounced dead at 10:05 a.m.

Days after Daniel's death Anna Nicole's Bahamian attorney, Michael Scott, described her as "overwhelmed" by grief. "She's trying to come to grips with the depths of her despair," he said.

Stern, who appeared on Larry King Live Tuesday, said Anna Nicole's baby daughter is "the one thing that is really keeping her going.

"Through it all, even with all the pain, she has been a great mom, a very attentive mom," he said.

Meanwhile, An attorney representing the Playboy Playmate said Tuesday he is the father of her daughter. Howard K. Stern added that he plans to marry Smith. "Anna and I have been in a relationship and we love each other, and it's been going on for a very long time, and because of my relationship as her lawyer, we felt that it was best to keep everything hidden," Howard K. Stern told CNN's "Larry King Live" ... Stern said he and Smith are confident he is the father, and "based on when the timing of when the baby was born, there really is no doubt in either of our minds."

Entertainment reporter and photographer Larry Birkhead also claims to be the father of the girl, named Danilynne Hope. In a statement, Birkhead said Smith told him he is the child's father, and that he has proof.

In an exclusive interview with Us, Birkhead calls Stern's comments “laughable." He adds: “I am not surprised he would say this but I am laughing at it. Larry King didn’t even believe Howard."

Birkhead also tells Us that he is willing to take a DNA test anytime to prove he is the father. “I have asked for a DNA test and I welcome it."