Dwarf long term pain killers?

[PurpleKat]

My 2.5 year old russian hybrid is on long term from the vet.
She mentioned that she may get some kidney problems.
Has anyone gotten this or had a similar experience.

She was started on meloxaid 0.5mg/ml at a 0.02ml dose daily, due to a suspected cancerous lump by her cheek. It didn't respond to antibiotics.
It has not shrunk or enlarged.
The pain killer was reduced slowly.
She's on it every 3 days now for the last 3 weeks.
I tried 4 days but she looked rough that day.

[souffle]

If the vet prescribed it and it provides pain relief then I wold continue with it as at this age she is quite elderly and you don't want her to be in pain even if it does mean taking a risk with side effects.