Which statement indicates effective teaching about sublingual nitroglycerin use?

The statement about calling an ambulance if pain persists after taking three nitroglycerin doses spaced five minutes apart demonstrates effective understanding and teaching regarding the use of sublingual nitroglycerin. This medication is specifically prescribed for the relief of angina (chest pain) and is intended for acute situations.

If the patient does not experience relief after three doses, it indicates that the angina may be severe, possibly signaling a more serious condition such as a heart attack. In such cases, emergency medical assistance should be sought immediately to ensure proper intervention and care. This understanding emphasizes the importance of recognizing when to escalate care, which is crucial for patient safety and effective management of cardiac symptoms.