Is it prescription? I may try it.
It’s prescription, at least in the US.
And it suppresses the immune system, so should not be taken without good reason.
I’ve taken it for a disc problem in my back.
Yes, you need a prescription. The second time I needed it I was with a new doctor and I had to push him just a little bit to write the Rx. I guess it has some downsides if taken for a prolonged time. But with one round of treatment my cough was entirely gone and did not come back for years.