6.8 Antianginal – Nitrates
Antianginal medication is used to treat angina pectoris. Angina is chest pain caused by inadequate blood flow, resulting in hypoxia of the cardiac tissue. Angina can be chronic pain caused by atherosclerosis in coronary artery disease or acute pain caused by a myocardial infarction.
Antianginals increase blood flow to the heart or decrease oxygen demand by the heart. Nitrates promote vasodilation of coronary arteries and veins. Beta-blockers and calcium channel blockers are also used to decrease workload of the heart and decrease oxygen demands.
Nitrates may come in a variety of routes, such as sublingual, extended-release tablets, creams, transdermal patches, and intravenously. The grid below focuses on administration via sublingual tablets. Sublingual tablets are prescribed PRN (“as needed”) for clients who are experiencing chronic, stable angina due to coronary artery disease.
Mechanism of Action: Nitroglycerin relieves angina by relaxing vascular smooth muscle, resulting in vasodilation.
Indications: Nitroglycerin is used to relieve angina due to coronary artery disease, during times of an acute attack, or prophylactically.
Nursing Considerations: Clients taking sildenafil (Viagra) or similar medications for erectile dysfunction in the previous 24 hours may not take nitroglycerin as this may result in a dangerous drop in blood pressure.
Nitroglycerin should not be used in pregnant women or those who are breastfeeding.
Nitroglycerin is contraindicated in clients who have severe anemia, increased intracranial pressure, hypersensitivity, or circulatory failure.
Side Effects/Adverse Effects: Clients taking nitroglycerin may experience hypotension, palpitations, headache, weakness, sweating, flushing, nausea, vomiting, or dizziness.
Health Teaching & Health Promotion: Clients should allow medication to dissolve under their tongue. This route allows immediate absorption into the circulation and avoids first-pass metabolism by the liver. Clients may take up to one tablet every 5 minutes or up to three sublingual tablets within 15 minutes to relieve chest pain. If chest pain is not relieved after the first dose, 911 should be called. Nitroglycerin may also be used prophylactically 5 to 10 minutes prior to engaging in activities that might precipitate an acute attack.
Instruct clients to avoid eating or smoking during administration as this may alter absorption. Clients should sit during administration to decrease the risk for injury due to the possibility of hypotension, dizziness, and weakness. Nitroglycerin decomposes when exposed to heat or light, so it should be stored in the original, airtight glass container. See Figure 6.23[1] for an image of nitroglycerin containers.[2]
Historically, clients have been taught to seek emergency help (call 911) if pain persists after the third dose of medication. However, new guidelines from the American Heart Association urge clients to call 911 after the first dose if symptoms are not improved or become worse.[3]
Now let’s take a closer look at the medication grid for nitroglycerin in Table 6.8.[4]
Table 6.8 Nitroglycerine Medication Grid
| Class/Subclass | Prototype/Generic | Nursing Considerations | Therapeutic Effects | Side/Adverse Effects |
|---|---|---|---|---|
| Nitrate | nitroglycerin | Clients may take up to three sublingual tablets within 15 minutes (one every 5 minutes) to relieve chest pain
If symptoms are not improved after the first dose or become worse or if the pain persists after the third dose of medication, seek emergency help (call 911). Nurses should check BP after each dose No eating or smoking during administration of SL tablet Do not chew or crush SL tablet Advise clients to sit while taking this medication Paste/Transdermal: Apply the paste or transdermal patch to a clean, dry area of skin on the upper body or arm. Rotate application sites to prevent skin irritation. Follow the medication instructions for how often to apply the paste or patch |
Decrease chest pain | Hypotension and palpitations
Headache, weakness, sweating, flushing, nausea, vomiting, and dizziness |
Critical Thinking Activity 6.8
A client was administered the first dose of nitroglycerin at 1305 for acute angina. What should the nurse evaluate after administration?
Note: Answers to the Critical Thinking activities can be found in the “Answer Key” section at the end of the book.
- “Nitroglycerin (1).JPG” by Intropin is licensed under CC BY 3.0 ↵
- This work is a derivative of DailyMed by U.S. National Library of Medicine in the Public Domain. ↵
- O’Gara, P., Kushner, F., Ascheim, D., Casey, D., Chung, M., de Lemos, J., Ettinger, S., Fang, J., Fesmire, F., Franklin, B., Granger, C., Krumholz, H., Linderbaum, J., Morrow, D., Newby, L., Ornato, J., Ou, N., Radford, M., Tamis-Holland, J., Tommaso, C., Tracy, C., Woo, Y., & Zhao, D. (2013). ACCF/AHA guideline for the management of ST-elevation myocardial infarction: A report of the American College of Cardiology Foundation/American Heart Association task force on practice guidelines. Circulation, 127(4). https://www.ahajournals.org/doi/full/10.1161/CIR.0b013e3182742cf6?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub%3Dpubmed ↵
- This work is a derivative of DailyMed by U.S. National Library of Medicine in the Public Domain. ↵