I am writing a work of fiction and want it as scientifically accurate as possible.

In theory, is racepinephrine (the active ingredient in Asthmanefrin) compatible as an emergency replacement for epinephrine to combat anaphylaxis?

Note: This question is not a personal health question nor a question seeking health advice, it is only a theoretical question born of a curiosity for the underlying pharmacology and biochemistry. I have never in my life had any kind of allergic reaction and your answer bears no effect on my health or anyone else's health.


This study answers that question. In it, researchers gave subjects 15 and later 30 puffs of racemic epinephrine and then measured the serum concentration of epinephrine. They later gave those same volunteers subcutaneous epinephrine at the dose commonly used to treat anaphylaxis, then again measured their serum epinephrine concentrations.

They found that 1 minute after the dose the 15 puffs caused a peak epi level of 1.50 nmol/L, 30 puffs caused a peak level of 4.2 nmol/L. These returned to baseline after 20 minutes. The subcutaneous dose caused peak levels of around 2.4 nmol/L at 10 minutes, which remained elevated at 40 minutes.

TL;DR: Inhaled epi can theoretically get you to high enough levels to treat anaphylaxis, but you would likely need to redose frequently as it is shorter acting.

  • Thank you so much Nate! One follow-up, what would happen in theory, if rather than inhaling it through an atomizer, they just dissolved the racepenephrine liquid into a saline solution at an equivalent common epinephrine dosage to treat anaphylaxis, and injected that mixture subcutaneously?
    – Brian
    Oct 24 '19 at 21:52
  • @Brian That's a new question so feel free to ask it. Comments aren't intended for lengthy discussion. And before you do that, you might want to upvote Nate's answer and accept it by clicking the check mark.
    – Carey Gregory
    Oct 25 '19 at 0:00
  • Sorry! New here :) I will upvote Nate's answer now. (My vote doesn't reflect because I have less than 15 repuptation)
    – Brian
    Oct 25 '19 at 13:45

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