Cardiovascular Medications Study Notes

Cardiovascular Medications Overview

  • Cardiovascular Medications: Drugs that affect cardiovascular function.
  • Types:
    • Inotropic drugs
    • Antiarrhythmic drugs
    • Antianginal drugs
    • Antihypertensive drugs
    • Diuretics
    • Antilipemic drugs

Inotropic Agents

  • Definition & Function:
  • Agents that alter myocardial contractility (the force of heart contractions).
  • Can have positive (+) or negative (-) effects.
  • Primary Classes:
  • Digitalis (e.g., Digoxin)
  • Phosphodiesterase Inhibitors (PDE Inhibitors, e.g., Milrinone)

Digitalis (e.g., Digoxin)

  • Mechanism of Action:
  • Increases intracellular calcium, leading to more forceful contractions.
  • Acts on CNS to slow heart rate (HR).
  • Indications:
  • Treatment of Atrial Fibrillation with Rapid Ventricular Response (A-Fib w/ RVR)
  • Atrial Flutter, Supraventricular Tachycardia (SVT), Paroxysmal Atrial Tachycardia (PAT).
  • Increases refractory period, reducing heart rate.
Interactions
  • Numerous drug interactions that can affect efficacy or increase toxicity:
  • Drugs reducing therapeutic effects
  • Drugs increasing dysrhythmias
  • Herbal Supplements: St. John’s Wort can interfere with Digoxin efficacy.
Adverse Effects of Digoxin
  • Signs of toxicity:
  • Nausea, vomiting, abdominal pain, diarrhea
  • CNS symptoms: headache, irritability, depression, insomnia, confusion
  • Visual disturbances: blurred/yellow vision
  • Cardiac issues: bradycardia, complete heart block
Nursing Process Considerations for Digitalis
  • Assessment:
  • Monitor vital signs, potassium (K) levels, digoxin levels, signs/symptoms (S/Sx) of toxicity.
  • Diagnosis:
  • Problems: Decreased cardiac output (CO), risk for injury.
  • Planning:
  • Set goals based on diagnosis
  • Implementation:
  • Administer as per protocol, monitor closely for adverse effects.
  • Evaluation:
  • Assess if goals of improved cardiac output and negative adverse reactions are met.

Phosphodiesterase Inhibitors (PDE)

  • Examples: Inamrinone, Milrinone
  • Uses:
  • Short-term treatment of Congestive Heart Failure (CHF).
  • Administered intravenously.
  • Mechanism of Action:
  • Increases calcium influx into cells and promotes smooth muscle relaxation, reducing preload and afterload.

Adverse Effects of PDE Inhibitors

  • Potentiate risk of hypotension, dysrhythmias, and cause nausea.
  • Must monitor potassium levels closely, especially with K-wasting diuretics.

Antidysrhythmic Medications

  • Purpose: Treat arrhythmias; can worsen existing rhythms.
  • Classes:
  • Class I: Sodium (Na+) channel blockers
    • Class IA: Quinidine, Procainamide
    • Class IB: Lidocaine, Phenytoin
    • Class IC: Flecainide, Propafenone
  • Class II: Beta Blockers (e.g., Propranolol, Metoprolol)
  • Class III: Potassium (K+) channel blockers (e.g., Amiodarone)
  • Class IV: Calcium (Ca2+) channel blockers (e.g., Verapamil, Diltiazem)

Class IA Antidysrhythmics — Details

  • Mechanism of Action: Reduce phase 0 depolarization by blocking Na+ channels, slowing action potential.
  • Indications: Treat various arrhythmias such as:
  • Atrial Fibrillation
  • Ventricular Tachycardia
  • Key Considerations:
  • Monitor ECG for changes.
  • Watch for potential drug interactions, especially with digoxin and warfarin.

Class IV Antidysrhythmics — Details

  • Function: Inhibit Ca2+ influx; can act as pseudo + inotropes.
  • Adverse Effects: Postural hypotension, bradycardia, AV block.

Antianginal Drugs

  • Subtypes:
  • Nitrates (e.g., Nitroglycerin)
  • Routes of Administration: Sublingual, oral, IV, transdermal.
  • Patient Education:
  • Check and store medications properly.
  • Notify healthcare provider of severe or persistent symptoms.

Antihypertensive Drugs

  • Classes:
  • ACE Inhibitors (e.g., Lisinopril)
  • Angiotensin II Receptor Blockers (ARBs)
  • Calcium Channel Blockers
  • Beta Blockers
  • Considerations:
  • Monitor vital signs, renal function, and electrolytes.
  • Educate patients on potential side effects and lifestyle modifications to manage blood pressure.

Common Adverse Effects of Antihypertensives

  • Dizziness, hypotension, dry cough (ACE inhibitors), hyperkalemia, and fatigue.

Antilipemic Agents

  • Include: Statins, Niacin, Bile-acid sequestrants.
  • Functions: Lower LDL cholesterol, increase HDL cholesterol, and manage triglyceride levels.
  • Clinical Considerations: Monitor lipid profiles and educate about dietary management.

Statins - Key Points

  • Mechanism: Inhibit cholesterol production.
  • Adverse Effects: Muscle pain, liver dysfunction, rhabdomyolysis.
  • Nursing Points:
  • Monitor CK levels, liver function tests, and educate regarding potential side effects and interactions.