The history with methoxyflurane (the active ingredient in...

The history with methoxyflurane (the active ingredient in Penthrox) is really poor. Essentially, 40 odd years ago, it was used in high dosage and created kidney damage. So the FDA is reluctant to approve this drug for clinical trials, and in fact has a hold on it. So MVP is trying to get the hold lifted. In the meantime, they have over 40 markets that have approved it; something like 7m data point of usage including 40+yrs in Aus and NZ use; etc. So any clinical trial will be positive, the risk is very low. But, gotta change the minds of the FDA first. I think the initial hope was get it approved in Europe, and that'll pressure the FDA through the data available to overturn it's legacy decision. This however has turned out to be a slow path.