Answer
Rifampicin colours urine and other body fluids orange-red. This is expected, but tears can permanently stain soft contact lenses.
Sources for this answer
- Rimstar Film-coated Tablet / Voractiv Film-coated Tablet — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.