A client with congestive heart failure arrives at the ER with a list of medications. Which medication on the list has the most implications for the client's health?

• A. Valium – seizures
• B. Captopril – high blood pressure
• C. Viagra
• D. Lasix – treats swelling

Answer: (C)

The medication with the most implications is the phosphodiesterase type 5 inhibitor used for erectile dysfunction. This drug can cause a dangerous drop in blood pressure when combined with nitrates or other vasodilators often used in heart failure or the ER for chest pain. In a patient with congestive heart failure, nitrates may be given, and pairing them with this medication can lead to severe hypotension and compromised blood flow to vital organs. That potential interaction makes it the most clinically significant concern on the list.

The other drugs have important roles too—sedation from a benzodiazepine, blood pressure effects from an ACE inhibitor, and fluid removal from a diuretic—but they don’t carry the same acute, high-risk interaction with common CHF treatments in the ER.