A client with a history of angina reports the onset of chest pain. The nurse determines that the heart rate is 104 beats/minute and the blood pressure is 138/86 mm Hg. A transdermal nitroglycerin patch was applied 30 minutes ago to the right upper chest. Which action should the nurse take?

A. Obtain another transdermal patch and position it on the client's left upper chest: Applying an additional patch is not appropriate, as transdermal nitroglycerin provides a continuous slow release of the drug and doubling patches could cause excessive hypotension. B. Withhold further doses of nitroglycerin until contacting the healthcare provider: This would delay pain relief and increase the risk of myocardial ischemia. Nitroglycerin protocols allow for PRN sublingual doses for breakthrough chest pain even when a patch is in place. C. Reassure the client that the patch will begin to take effect within a few minutes: Transdermal nitroglycerin has a delayed onset, often requiring 30–60 minutes for therapeutic levels. Relying solely on the patch for acute angina relief is unsafe, as sublingual nitroglycerin provides rapid action within minutes. D. Leave the patch in place and administer a PRN dose of sublingual nitroglycerin: The patch provides baseline therapy, while sublingual nitroglycerin offers rapid symptom relief for acute episodes. This combination ensures immediate pain control without interrupting ongoing prophylactic treatment.