Final answer:
The nurse should be concerned about the client taking nitroglycerine who is getting married and worried about erectile dysfunction because combining nitrates with ED medications like Viagra can lead to severe hypotension and is potentially life-threatening.
Step-by-step explanation:
The nurse would be most concerned about the statement "I'm getting married tomorrow; I hope my erectile dysfunction isn't a problem." This is concerning because nitroglycerine, which the client takes for occasional stable angina, is a vasodilator similar to sildenafil (Viagra), a medication used to treat erectile dysfunction (ED). Men with cardiac conditions taking nitrates, like nitroglycerine, should not take ED medications such as Viagra due to the risk of severe hypotension and other potentially life-threatening interactions. Since deaths have been reported for at-risk users combining nitrates with ED drugs, the client should be advised against using these medications without discussing with their physician.