Doctors do, otherwise they wouldn’t be using them.

Doctors gave my SO’s mom Fentanyl. What she has is pure, clean, dosed properly, and basically harmless.

“All things are poison and nothing is without poison; only the dose makes a thing not a poison.”

~Theophrastus von Hohenheim the father of pharmacological medicine

I’m going to go out on a limb here and guess that you have no medical background whatsoever, because being a medical professional wouldn’t allow you to have such a black and white thought process on such a nuanced topic as whether a drug was healthy or not. Vitamins are considered healthy, but if you take too much vitamin A you’re brain is gonna swell up and take on water, your bones are gonna hurt, your nails will become brittle and break, etc. If you don’t have enough you will go night blind, have trouble conceiving, get terrible acne, and be unable to heal wounds.