The nurse is caring for an older adult who is receiving diphenoxylate with atropine to treat severe diarrhea. The nurse will monitor this patient closely for which effect?

A. Bradycardia Bradycardia is not a common side effect of diphenoxylate with atropine. Atropine, which is included in the combination, has anticholinergic effects that can lead to an increased heart rate (tachycardia), not bradycardia. B. Fluid retention Fluid retention is not a common side effect of diphenoxylate with atropine. In fact, the medication is used to treat severe diarrhea, and the goal is to decrease fluid loss associated with diarrhea rather than causing fluid retention. C. Nervousness and tremors Nervousness and tremors are not common side effects of diphenoxylate with atropine. Atropine's anticholinergic effects may cause nervousness, but these effects are generally not prominent at therapeutic doses. D. Respiratory depression This is the correct choice. Respiratory depression is a potential side effect of diphenoxylate with atropine, particularly if the medication is misused or taken in excessive amounts. Atropine is included in the combination to discourage misuse, as it can cause unpleasant anticholinergic effects.