Antianginal Drugs Overview

Antianginal Drugs

• Balance: Myocardial oxygen supply needs to balance with demand. Coronary arteries supply oxygen.
• Angina Pectoris: Chest pain due to insufficient oxygen supply to the myocardium.
  • Stable: Caused by atherosclerosis, worsened by exertion, relieved by rest or medication.
  • Unstable: Shows early signs of Coronary Artery Disease (CAD), unpredictable, and can lead to a heart attack (MI).
• Ischemia: Cellular/tissue damage due to inadequate blood supply
• Atherosclerosis: Plaque buildup in artery walls, causing narrowing.
• CAD: Atherosclerosis in the coronary arteries
• Myocardial Infarction (MI): Blockage of blood flow to the heart muscle, leading to tissue death.
• Classes of Antianginal Drugs:
  • Nitrates
  • Beta Blockers
  • Calcium Channel Blockers
  • Ranolazine (newest, unknown mechanism)

Nitrates

• Mechanism: Dilate coronary arteries, increasing blood flow and oxygen.
• Example Drugs: Nitroglycerin (IV, ointment, spray, sublingual, transdermal patch), Isosorbide dinitrate (PO), Isosorbide mononitrate (PO)
• Contraindications: Severe anemia, hypotension, erectile dysfunction drugs.
• Side Effects: Low blood pressure, headaches.

Beta Blockers

• Mechanism: Decrease heart rate and oxygen demands, decrease risk of dysrhythmias, improve survival after a heart attack (MI).
• Example Drugs: Carvedilol, metoprolol, atenolol
• Contraindications: bradycardia, hypotension.
• Nursing Considerations: Do not stop abruptly to avoid rebound effect of tachycardia.

Calcium Channel Blockers

• Mechanism: Work in different ways to relax smooth muscles, leading to arterial dilation.
• Example Drugs: Amlodipine, nifedipine (Dihydropyridines), diltiazem, verapamil (Benzothiazepines and phenylalkylamines).
• Dihydropyridines: Relax arterial smooth muscles but don't affect cardiac conduction.
• Benzothiazepines/Phenylalkylamines: Reduce myocardial contractility, affect SA and AV node conduction (also antidysrhythmic effects).

General Considerations for Antianginal Drugs

• Monitor Vital Signs (VS) and Labs.
• Assess Patient.
• Desired Outcomes: Reducing chest pain.
• Medication Interactions: Important to note and monitor.
• Do Not Stop Abruptly: Take as prescribed.
• Ranolazine: Reserved for patients who have not benefited from other antianginal drugs; may cause cardiac dysrhythmias.

Additional Information

• Nursing considerations include patient education, monitoring for adverse effects, avoiding abrupt discontinuation, and recognizing potential complications like worsening heart failure.
• Important monitoring points include heart rate, rhythm, blood pressure, desired outcomes (like maintaining chest pain relief), and recognizing worsening heart failure symptoms.