A patient taking bismuth subsalicylate [Pepto-Bismol] has a black tongue on examination. What should the NP do?

• A. Reassure the patient that this is an expected side effect.
• B. Consider this a sign of GI bleeding.
• C. Suspect hepatotoxicity.
• D. Assess for drug overdose.

Answer: (A)

Discoloration of the tongue is a known, harmless effect of bismuth subsalicylate. The bismuth can react with sulfur compounds in saliva and on the tongue to form black bismuth sulfide, giving the tongue a dark appearance. This does not indicate bleeding, liver injury, or overdose, so the appropriate action is to reassure the patient and continue the medication as directed. If new symptoms suggestive of GI bleeding (such as vomiting blood or black, tarry stools) or salicylate toxicity (for example ringing in the ears, persistent confusion, or rapid breathing) appear, those would warrant further evaluation.