Good article from The Dose Makes the Poison blog.  You can read the entire article here.

I found the following excerpt fascinating.  The bold lines are my highlights.

From a general forensic toxicology standpoint, the real takeaway is that this is a dangerous combination of substances to use concurrently. He was consuming two powerful opioid and two potent benzodiazepines which when used together can create synergistic effects and exaggerated central nervous system depression. Add that situation to an already compromised cardiovascular and respiratory system, and it’s a recipe for disaster.  For my own information, I would love to see the full toxicology report with quantitative measures of drug, etc. How much fentanyl was present? How much temazepam and alprazolam were detected? Not that any of that really matters though.

With the detection of acetylfentanyl and despropionylfentanyl, it seems as if Tom Petty was supplementing his pharmaceutical medications with illicitly manufactured substances. Acetylfentanyl is not a pharmaceutical medication anywhere in the world and is only found as a designer opioid/analog meant to skirt the controlled substances act in the USA. Fentanyl does not metabolize to acetylfentanyl. As despropionylfentanyl is a precursor/intermediate used in the illicit (non-pharmaceutical) synthesis of fentanyl, it generally used as a marker for exposure to illicitly manufactured fentanyl. The presence of this substance has also been associated with the use of various fentanyl analogs including acetylfentanyl, acrylfentanyl, and furanylfentanyl. No one knows if the use of illicit opioid was intentional or not. Remember the situation surrounding Prince’s death. Multiple pills were found in his residence that looked like pharmaceutical hydrocodone/acetaminophen but turned out to be counterfeit tablets containing fentanyl and the opioid research chemical U-47700.

As a conclusion, I’ll say, please do not mix depressant drugs. Do not mix opioids with benzodiazepines. Do not mix either of them with ethanol. Stay safe, folks.

Pay attention to those medications.

Didn’t I mention this previously when writing about Heath Ledger’s death?