Cardiovascular Drugs (Vasodilators, Nitrates, Antiarrhythmics, Cardiac Glycosides)

Overview

• Continuation of cardiovascular drug discussion.
• Focus on various classes: vasodilators, nitrates, antiarrhythmics, and cardiac glycosides.
• Study guide includes related reading sections and hyperlinks.

Vasodilators

• Examples: Minoxidil, Hydralazine, Nitroprusside
• Action: Act directly on vascular smooth muscle to cause vasodilation, relaxing arterial walls, lowering blood pressure, reducing resistance.
• Primary Use: Hypertension
• Secondary Uses: To be discussed.
• Reactions:
  • Risk of hypotensive crisis if blood pressure drops too quickly
  • Palpitations due to heart's response to lower blood pressure
  • Chest pain due to reduced blood flow to heart muscle
  • Symptoms may include systemic lupus erythematosus (SLE), neurological impacts (tremors, numbness, tingling, disorientation), sinus and GI tract effects, headaches.
• Nursing Considerations:
  • Monitor blood pressure closely
  • Watch for signs of lupus
  • Educate on drug compliance and signs of hypotension, especially orthostatic hypotension

Nitrates

• Specific grouping of vasodilators
• Example Name Ending: Nitrate
• Action: Quick-acting vasodilators focused on the cardiac circulation
• Primary Use: Angina prevention, chest pain treatment
• Reactions:
  • Risk of hypotension
  • Palpitations and common occurrence of headaches with fast-acting nitrates like sublingual nitroglycerin
  • Weakness, sweating, dizziness due to hypotension
• Nursing Considerations:
  • Monitor blood pressure
  • Educate on signs of hypotension
  • Avoid eating or smoking when using sublingual forms
  • Warn against use with sildenafil (Viagra) due to significant blood pressure drop risk
  • Emergency dosing schedules and EMS activation

Antiarrhythmics

• Action: Change cardiac conduction system to generally slow down and stabilize it
• Usage: Primarily for tachycardias or rapid heart rate dysrhythmias
• Class Details:
  1. Class I: Sodium channel blockers - Decrease sodium flow, slow heart rate, stabilize conduction, avoid grapefruit juice due to toxicity risk.
  2. Class II: Beta blockers (e.g., -olol drugs) - Slow heart rate, considerations differ from anti-hypertensive use.
  3. Class III: Potassium channel blockers (e.g., Amiodarone) - Slow heart rate, high toxicity risk, multiple drug interactions, close monitoring required.
  4. Class IV: Calcium channel blockers - Slow heart rate, decrease contractility, considerations include vital sign monitoring.

Cardiac Glycosides

• Example: Digoxin
• Action: Work on sodium-potassium pump; decrease heart rate but increase contractility
• Usage: Heart failure in later stages, atrial fibrillation
• Reactions:
  • Risk of tox icity
  • GI related symptoms, bradycardia, bradyarrhythmias
• Nursing Considerations:
  • Monitor apical heart rate, withholding if below provider's parameters
  • Long-term use requires monitoring of digoxin and potassium levels
  • Educate on GI symptoms of digoxin toxicity

Conclusion

• End of section on cardiac drugs, next topic will be covered in the following video.