Tox Myth-Bust – Prehospital Exposure to Fentanyl Analogs

January 31, 2019

Summary by Alex Chen, MD
Expert Peer Review by Jerry Snow, MD

Spoon Feed

1. Concern for exposure should not delay treatment of patients.

2. Responders are unlikely to have toxicity with incidental contact. Nitrile gloves are sufficient for most scenarios.

3. Wash body surfaces that come in contact with fentanyl with water. Alcohol-based sanitizers may increase absorption.

4. In the unlikely situation where there is concern for aerosolized fentanyl, a well-fitted N95 respirator should be sufficient.

5. Give naloxone to those with signs of hypoventilation. Fentanyl analogs often respond to normal doses of naloxone. Titrate to response, up to 10mg.

Why does this matter?
As fentanyl and fentanyl analogs are becoming increasingly common, emergency responders are likely to come into contact with these substances in some form. There has been significant concern about occupational exposure and stories circulating about responders succumbing to the drug via incidental contact. This has led agencies such as the DEA and NIOSH to propose recommendations on personal protective equipment. While it is extremely important to protect our emergency responders, it also must balance limited resources and timely assistance for patients. This position statement by ACMT and AACT addresses specific concerns about occupational exposure to fentanyl with the literature that is currently available.

The facts on fentanyl

Transdermal exposure
While fentanyl is amenable to transdermal absorption due to its lipophilicity and low molecular weight, clinically significant absorption is dependent on multiple factors that are not present with incidental contact. Fentanyl patches are a common form of transdermal delivery device, and they require 3-13h to reach therapeutic levels and even longer to reach peak levels. That is the reason why fentanyl patches are not used in the management of acute pain. These patches are in constant close contact with the skin and provide a moist environment to increase absorption, whereas powdered drug and pills lack both of these characteristics. If a person covered both palms in fentanyl patches, it would require approximately 14 minutes to absorb 100mcg of fentanyl. The possibility of being knocked down instantly due to brushing fentanyl powder off with bare hands does not seem feasible. Using standard nitrile gloves and basic precautions such as washing body surfaces with water after contact are sufficient to minimize exposure. If there is the potential for heavy contamination where you will likely be exposed to a large amount of powdered drug or liquid drug, water-resistant coveralls can be used. 

Inhalational exposure
While inhalational exposure has significant bioavailability, it is highly unlikely to be exposed to aerosolized fentanyl or analogs. Vapor pressure gives you an idea of how likely a liquid is to convert to the gas phase. Higher vapor pressure means the substance is more volatile and more likely to convert to a gas. At around room temperature, the vapor pressure of fentanyl is very low (4.6 x 10-6 Pa, compared to water which is 3173 Pa). This means that it is very unlikely for fentanyl found in solid or liquid form to evaporate under normal conditions. In the scenario where there are multiple people down and there is concern for possible weaponized fentanyl or fentanyl analogs, a N95 or P100 respirator should be sufficient to protect against exposure.

Naloxone administration
While it makes sense that something that has 50-100x (10,000x in certain analogs) the potency of morphine would require heroic doses of naloxone to reverse, there is scant literature to back this up. In our experience, the patients with confirmed illicit fentanyl exposure that we admit to our toxicology service (Banner University Medical Center – Phoenix) have, by and large, responded to standard doses of naloxone (0.4mg-2mg). While we have had patients require multiple repeat doses, we have not seen a significant difference in the bolus doses required to reverse hypoventilation. Until there is better data to guide naloxone administration, it is reasonable to give standard doses, titrated to effect up to 10mg. Just be aware that they may require additional doses.

Another Spoonful

• Andrew Stolbach has a great post on Tox & the Hound with a very important comment below by Steven Curry that is worth a read.

• See this guide from the CDC.

• And a great opinion piece on PBS

Source
ACMT and AACT position statement: preventing occupational fentanyl and fentanyl analog exposure to emergency responders. Clin Toxicol (Phila). 2018 Apr;56(4):297-300. doi: 10.1080/15563650.2017.1373782. Epub 2017 Sep 5.

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