On Jan. 22, 2008, Ledger (right) was found unconscious in his apartment and pronounced dead less than an hour later. Speculation followed until early February when an autopsy and toxicology report from the chief medical examiner's office in New York revealed that he had died as a result of acute intoxication by the combined effect of several medications.

In a recent interview, Dr. Rebecca Tominack, adjunct professor of medical toxicology at St. Louis University School of Medicine, put the findings in perspective. The death was accidental, neither a homicide nor a suicide, she said. It was "very clearly a result of prescription medication abuse."

The lethal combination of medications in Ledger's system included oxycodone (contained in the drug OxyContin, a controlled substance often used in cancer patients suffering from pain) and hydrocodone (one of the ingredients in the drug Vicodin, another medication commonly used to treat pain), as well as three benzodiazepines: alprazolam, diazepam and temazepam. Alprazolam (Xanax) and diazepam (Valium) are very commonly used to treat anxiety while temazepam (Restoril) is more often used as a sleep aid.

An additional medication found in the toxicology screen was the non-prescription doxylamine, an antihistamine known to cause drowsiness and found in many over-the-counter cold medicines. "Over-the-counter drugs are usually therapies that used to be prescription only," said Tominack. "These are regular medications in effective doses; treat them with respect."

'Brokeback' system

Ledger's death is another wakeup call to larger issues. A broken healthcare system is in large part to blame: fragmentation of care and a patient's failure to disclose all medicines in possession are likely contributors to this tragedy.

It is likely that Ledger had gotten prescriptions filled by more than one provider and also highly likely that each provider had no knowledge of the other medicines in his possession. "To be totally safe with your meds, you have to be totally honest - brutally honest" with your healthcare professionals, Tominack said. And further, "use the same pharmacy so there is a medication record," which can help avoid potential adverse outcomes of inappropriate combinations.

But the problems may not be so easily addressed: "People hide things on purpose. They don't want to be told not to take that much Vicodin," said Tominack. "It may mean you don't get what you came in for, which may mean extra pain pills, but it just might give the extra margin of safety needed."

The age of information technology

Using medication-alert software may also be helpful. Programs such as Micromedex and Epocrates are among those available to health care professionals for a fee. Prescribers can type in a list of medications and determine what, if any, adverse reactions are possible. And the Internet has a wealth of information for consumers that can assist patients in their own search for answers.

It is also advisable, when in doubt, to tell your pharmacist what you are taking and what medical conditions you have. These professionals are trained in what to look out for and what conditions could set the stage for disaster.