A patient is taking bismuth subsalicylate [pepto-bismol] to prevent diarrhea. the nurse performing an assessment notes that the patient's tongue is black. what will the nurse do?

The nurse should assure the patient that black tongue is an expected side effect of taking that particular drug. The active ingredient in the drug contain bismuth. The tongue and the alimentary canal of humans contain trace amount of sulphur, when bismuth comes in contact with this sulphur, bismuth-sulphide will be formed. Bismuth-sulphide is an harmless by product, thus, the tongue discoloration observed in the patient is harmless.