Major Drug Classes
Nitrates
- Nitroglycerin (sublingual, transdermal, oral) and isosorbide dinitrate work by causing vasodilation of coronary arteries and reducing preload. They convert to nitric oxide, which relaxes vascular smooth muscle.
- Critical nursing consideration: Monitor for hypotension and headache; patients should sit or lie down when taking sublingual nitroglycerin to prevent falls from orthostatic hypotension.
Memory Aid: "SIT and SPIT" - Sit down, Sublingual under tongue, If no relief in 5 minutes take another, Total of 3 doses max, then call 911
Beta-Blockers
- Metoprolol, atenolol, propranolol reduce myocardial oxygen demand by decreasing heart rate, contractility, and blood pressure. They block beta-1 receptors in the heart.
- Contraindicated in patients with asthma, COPD, heart block, or severe bradycardia due to risk of bronchospasm and further cardiac depression.
Calcium Channel Blockers
- Amlodipine, diltiazem, verapamil reduce oxygen demand by decreasing afterload and may increase supply through coronary vasodilation. They block calcium influx into cardiac and smooth muscle cells.
- Monitor for peripheral edema, constipation (especially verapamil), and gingival hyperplasia as common side effects requiring patient education.
Nursing Implications and Patient Care
Assessment and Monitoring
- Assess baseline vital signs, especially blood pressure and heart rate before administration
- Monitor for signs of hypotension: dizziness, weakness, syncope
- Evaluate pain relief using 0-10 pain scale for anginal episodes
- Check for drug interactions, especially with other cardiovascular medications
Clinical Scenario: A 65-year-old patient with stable angina is prescribed sublingual nitroglycerin. The patient reports dizziness after taking the medication. The nurse should instruct the patient to sit or lie down immediately and monitor blood pressure, as this indicates orthostatic hypotension from vasodilation.
Patient Education
- Teach patients to store nitroglycerin in original dark container away from heat and light, and replace every 6 months as potency decreases over time.
- Instruct on proper sublingual technique: place tablet under tongue, do not chew or swallow, expect slight burning sensation indicating active medication.
- Emphasize importance of not stopping beta-blockers abruptly due to risk of rebound hypertension and increased anginal episodes.
Commonly Confused Points
| Medication |
Primary Action |
Key Side Effect |
Major Contraindication |
| Nitroglycerin |
Vasodilation |
Headache, hypotension |
Viagra use (within 24-48 hours) |
| Beta-blockers |
↓ HR, ↓ contractility |
Bradycardia, fatigue |
Asthma, heart block |
| Calcium Channel Blockers |
↓ Afterload, vasodilation |
Peripheral edema |
Heart failure (some types) |
Memory Aid for Nitrate Tolerance: "Take a BREAK" - patients need nitrate-free periods (usually 8-12 hours) to prevent tolerance development