More now than ever, I am consulted as a toxicologist to opine on criminal and civil cases that involve opioids (prescription and illicit). Although there are countless case-specific questions, there are a few facts to give attorneys insight into their opioid-related cases from a scientific-perspective. There are actually more than a few facts (and lots of science to explain!) so I am looking forward to presenting a one-hour continuing legal education talk in June at the 2019 Pennsylvania Bar Institute Criminal Law Symposium entitled “Opioids: A Primer in Toxicology for Attorneys”.
Just to shed light on some terminology, opiates are compounds derived from the opium poppy plant, namely morphine and codeine. (Side note: who said natural products were necessarily safe? That’s a topic for another time.) Opioids are synthetic (eg, fentanyl) or semi-synthetic drugs (eg, heroin, oxycodone, hydrocodone). However, the term opioid is now used to encompass both of these families of drugs that bind to opioid receptors in the body.
- The dose makes the poison. Well, the dose also makes the toxicology screen positive or negative (there are minimum detection limits on toxicology screens). Yes, poppy seeds are from the opium poppy plant. But one poppy seed bagel is not going to give a positive opioid drug screen. How many will? Let’s just say more than your stomach would care to digest.
- Naloxone is not the only opioid-antagonist (meaning, it kicks an opioid off the opioid receptors in the body and reverses its effects). But it is the one that works the fastest (which is key for acting as a life-saving antidote). Naloxone does not affect opioid blood levels. It is structurally related to the opioid oxymorphone (with some modification), interestingly enough, but its presence is unlikely to yield a positive opioid drug screen (note that a “drug screen” is different than a confirmatory test). There are reports in the literature of this happening. However, it’s uncommon and if there is a question, dig into the laboratory testing data or check with the laboratory. More on naloxone from my CLE talk at Jenkins Law Library.
- Levels of opioids (blood, urine, antemortem, postmortem) are all over the map in terms of what reflects a fatal dose. Why? Simply put, tolerance, the presence of other drugs in the patient’s system (eg, benzodiazepines), and the source of testing (more relevant in postmortem toxicology testing) are all factors to consider when interpreting opioid levels and their relation to toxicity.
- Naloxone does not work 100% of the time. This antidote may not have been given early enough in the downward spiral of the opioid-poisoned patient’s clinical course, the dose was not high enough (eg, large dose of fentanyl), or a combination of the two.
- Being in the mere presence of fentanyl will not put someone at risk for fentanyl poisoning (despite reports in the media). Now, if someone gets it on their hands and then eats without washing their hands or licks their hands, or if the fentanyl becomes aerosolized, then there is risk for great harm. Dermal exposure is risky but more so because the person may not realize they have the fentanyl on their skin and allow it to slowly absorb (fentanyl does not instantly absorb through the skin and enter the bloodstream). The fentanyl has to get into the blood and in order to do so it must cross our skin barrier (again, not instant) or get through one of our mucous membranes (eg, mouth, nasal passage). The ways on-scene responders can stay safe in such situations is beyond the scope of this article.
Dr. Muller is available to present seminars to attorneys on drugs of abuse and other toxicology-related topics. She has presented numerous continuing legal education programs to attorneys with an interest in learning the science behind their drug, chemical, and alcohol cases. She can be reached at Allison@AcriMullerConsulting.com.