What unexpected bodily change may occur due to the use of rifampin?

The use of rifampin is known to cause a distinctive reddish-orange discoloration of body fluids, including urine, sweat, saliva, and tears. This occurs because rifampin, a potent antibiotic, interacts with various metabolic processes in the body, leading to the formation of colored metabolites. This side effect can be surprising for patients, as they may not be aware that their bodily fluids can change color while undergoing treatment with rifampin.

Additionally, this change is generally harmless but can have implications for patients, such as affecting the appearance of contact lenses or leading to concerns about potential staining of clothing or bedding. Understanding this side effect is important for proper patient education and to reassure patients that this is a normal and expected outcome of rifampin therapy, rather than a sign of an adverse reaction or toxicity.