[News - International] - Jackson's death raises questions about drug interactions

As friends of pop star Michael Jackson discuss the role prescription drugs may have played in his Thursday death, the serious health problems that can be triggered by drug interactions are again in the spotlight.

Some drugs have serious side effects in combination with other medications. Check with your doctor.

Dr. Deepak Chopra, who knew Jackson for more than 20 years, on Friday told CNN's Wolf Blitzer that he blamed Jackson's death on drug abuse, though he offered no direct evidence. "When you have enough drugs in your system, your heart goes into an arrhythmia and your respiration stops," he said. "I think the drugs killed him."

Authorities said Friday the cause of Jackson's death will not be determined officially for weeks. The results of toxicology tests are expected in six to eight weeks, said Ed Winter, assistant chief coroner for Los Angeles County.

Chopra said he had known Jackson to take the opium-derived painkiller OxyContin at one time, as well as injections of the narcotic pain reliever Demerol "and other narcotics, and I was really desperate to try to help him, but you know you can't help somebody who would go into denial."

Studies have shown that drug interactions are a huge problem, especially among older Americans. A 2008 study in the Journal of the American Medical Association showed that about 2.2 million people age 57 to 85 were taking potentially dangerous combinations of drugs.