Earlier quoted context omitted.
They are supposed to have learned about it in medical school. If not, that's fine, maybe doctors shouldn't be allowed to prescribe and maybe only pharmacists should be allowed. My point is that it's a very valuable professional quality and we should put the responsibility where the quality is.
This is (well, was) a new drug. Doctors cannot have learned about a drug in medical school when that drug did not exist when they were studying. My parents are retired Dutch GPs who also ran a small pharmacy[0], so I know a little about how this works, at least in the Netherlands (I admit that this is a pretty big caveat, because (aside from the obvious biases that this introduces) the opioid crisis doesn't exist her…
There are lots of FDA-approved drugs that are highly inappropriate for most patients. One of the reasons we tolerate the professional status of physicians is because of their purported expertise in prescribing these drugs safely. If they don't know the function and habit-forming potential of opioids, one might well question that expertise. They aren't regulated in any sense by FDA, and they can't blame FDA for their ignorance.