Rifampin or rifabutin can cause tooth staining or orange urine.
Here is a list of the side effects to be alert for.
https://medlineplus.gov/druginfo/meds/a682403.html
I took mine in combination with 2 other drugs for over 18 months, and did not have serious side effects, but my teeth seemed more inclined to sticky plaque, so I Khadr them cleaned every 3-4 months.
Sue