I was asked this question on Friday, I was asked earlier in the week, I've been asked before and I'm sure I'll be asked again.
Methotrexate, as the go-to drug for rheumatologists (read this explanation why) is something we discuss all the time with patients. It continues to amaze me how much misinformation there is about this medication.
The answer is pretty straightforward, and likely similar to the answer for any drug used long-term to treat a chronic disease.
My standard spiel:
For as long as it works really well in controlling the disease
and
it doesn't cause you to have any side effects that worry you (or me)
and
there are no abnormalities in any of the monitoring tests we will do.
Basically, the potential benefits must outweigh the potential risks.
If and when that situation changes, we reconsider. Often, we stop the medication and try another option if still required.
What have you been told about a long-term medication when you ask such a question?