Demerol carries a long list of warnings to users. The government warns that mixing it with certain other drugs can lead to reactions including slowed or stopped breathing, shock and cardiac arrest.

Within hours of Jackson's death on Thursday, fans were inundating Web sites that sell his music, and physical stores reported they had been cleaned out of Michael Jackson and Jackson 5 CDs. All 10 of the albums on Amazon.com's bestseller list Friday were Jackson's; the 25th anniversary edition of "Thriller," the bestselling album of all time, was at the top.

Meanwhile, fans were snapping up every Jackson recording they could get their hands on.

Bill Carr, Amazon.com Inc.'s vice president for music and video, said the Web site sold out within minutes all CDs by Michael Jackson and by the Jackson 5. Jackson's albums accounted for all 10 of Amazon's "Bestsellers in Music" list Friday, with the 25th anniversary edition of the celebrated "Thriller" album taking the top spot.

Barnes and Noble Inc.'s Web site and retail stores also sold out most Jackson CDs, DVDs and books, and its 10 best-selling CDs were Jackson titles as well.

"They love him," said Bill Carr, Amazon's vice president for music and video. "He's a legend, and they're anxious to make sure they have his music in their collections."

Associated Press writers Lynn Elber, Gillian Flaccus and Thomas Watkins contributed to this report.