Which condition would cause the nurse to withhold a PRN order for magnesium hydroxide?

A. Request an order for liver function tests to evaluate for hepatotoxicity: Bismuth subsalicylate is not associated with hepatotoxicity, and a black tongue is not indicative of liver dysfunction. There is no need for liver enzyme testing based solely on tongue discoloration.

B. Withhold the drug, because this is a sign of bismuth overdose: A black tongue is not a sign of overdose but rather a known harmless side effect due to the interaction of bismuth with sulfur in the saliva. Discontinuation is not warranted.

C. Assess further for signs of gastrointestinal (GI) bleeding: Although bismuth can cause dark stools, which may resemble melena, a black tongue specifically is not an indication of GI bleeding. Unless there are other signs, further assessment is unnecessary here.

D. Reassure the patient that this is an expected side effect of this drug: Bismuth subsalicylate often causes temporary blackening of the tongue or stool due to its chemical composition. This effect is benign and reversible, and reassurance is the appropriate nursing response.

A. Abdominal pain: Loperamide is not indicated for isolated abdominal pain and may actually worsen symptoms if used inappropriately, especially if the pain is related to a bowel obstruction or inflammatory condition.

B. Infection: While diarrhea may accompany infection, loperamide is typically avoided in infectious diarrhea, especially when caused by bacteria or toxins, because it can delay pathogen clearance and worsen the illness.

C. Diarrhea: Loperamide is an antidiarrheal agent that slows intestinal motility, allowing more fluid absorption in the colon. It is commonly prescribed PRN for symptomatic relief of non-infectious diarrhea.

D. Constipation: Administering loperamide in the setting of constipation would exacerbate the condition. It further reduces bowel motility, increasing the risk of fecal impaction or ileus.