Q+A-How painkillers could cause cardiac arrest

By Julie Steenhuysen

CHICAGO (Reuters) - The death of pop music icon Michael Jackson from cardiac arrest on Thursday has raised a host of questions about what might have caused it.

It may take weeks before an autopsy can reveal the true circumstances that led the singer's heart to stop.

One possible cause reported by celebrity website TMZ.com is that he was injected with the potent painkiller Demerol before he went into cardiac arrest.

Others speculate it was a combination of Demerol and Oxycontin, another powerful painkiller that is among the most commonly abused prescription drugs.

Here are some facts about cardiac arrest and both these drugs.

HOW COULD DEMEROL CAUSE CARDIAC ARREST?

Cardiac arrest occurs when the heart stops circulating blood. In 80 percent of cases, the cause is heart disease, but narcotic painkillers like Demerol can cause cardiac arrest.

Dr. Daniel Simon, chief of cardiology at University Hospitals Case Medical Centre in Cleveland, said if Jackson had been injected with too much Demerol, it might have caused him to stop breathing, a condition called respiratory arrest.