Before administering bethanechol, which medication should the nurse ensure is available for emergency use?

Bethanechol is a cholinergic agonist that stimulates the bladder to promote urination, commonly used to treat urinary retention. Due to its mechanism of action, it can potentially lead to significant cholinergic side effects such as bradycardia (slowed heart rate), hypotension, and increased secretion of bodily fluids.

Atropine sulfate is an anticholinergic medication that can counteract the effects of excessive cholinergic stimulation. Having atropine sulfate available is crucial in case the patient experiences severe bradycardia or other cholinergic crisis symptoms as a result of bethanechol administration. It serves as a safety measure, allowing for rapid intervention if any adverse reactions occur.

In contrast, the other medications listed have different uses and would not effectively manage the side effects associated with cholinergic agents. For instance, adrenaline primarily treats severe allergic reactions and cardiac arrest, calcium gluconate is used for hypocalcemia or magnesium toxicity, and ephedrine is a stimulant that may increase heart rate but would not address the specific cholinergic side effects. Therefore, ensuring the availability of atropine sulfate is the most appropriate precaution before administering bethanechol.