I was just answering a text from my son-in-law (an MD) and I asked him about this. He’s not super impressed by acetaminophen but it is common to recommend it. When the patient says they aren’t helped by it, he says physicians automatically get concerned that the patient is “drug seeking”, which is something they deal with very commonly.
He says it is common for someone to say that acetaminophen does nothing, so then the physician mentions ibuprofen. They reply with a specific problem they have with that. This goes on until everything has been eliminated except for the narcotic they are seeking.