Classification of Drugs Used in Congestive Cardiac Failure
1. Diuretics
Mechanism: Promote renal excretion of sodium and water, reducing fluid overload and edema, decreasing cardiac workload.
Examples: Furosemide, Bumetanide, Hydrochlorothiazide.
2. ACE Inhibitors
Mechanism: Inhibit the conversion of angiotensin I to angiotensin II, leading to vasodilation and reduced preload and afterload.
Examples: Enalapril, Lisinopril, Ramipril.
3. Angiotensin II Receptor Blockers (ARBs)
Mechanism: Block the action of angiotensin II, resulting in vasodilation and reduced blood pressure.
Examples: Losartan, Valsartan.
4. Beta-Blockers
Mechanism: Decrease heart rate and contractility, reducing myocardial oxygen demand.
Examples: Carvedilol, Metoprolol, Bisoprolol.
5. Aldosterone Antagonists
Mechanism: Inhibit aldosterone's effects, promoting sodium and water excretion.
Examples: Spironolactone, Eplerenone.
6. Positive Inotropic Agents
Mechanism: Increase contractility of the heart muscle, improving cardiac output.
Examples: Digoxin, Dobutamine, Milrinone.
7. Phosphodiesterase-3 (PDE3) Inhibitors
Mechanism: Increase intracellular cAMP levels, enhancing contractility and causing vasodilation.
Examples: Milrinone, Amrinone.
Digoxin
Mechanism of Action
Digoxin inhibits the sodium-potassium ATPase pump in cardiac myocytes, increasing intracellular sodium and calcium levels, enhancing cardiac contractility, and reducing heart rate.
Therapeutic Uses
- Heart Failure: Improves symptoms and quality of life in patients with reduced ejection fraction.
- Atrial Fibrillation: Controls ventricular rate and may restore sinus rhythm.
Adverse Effects
- Gastrointestinal: Nausea, vomiting, diarrhea.
- Cardiac: Bradycardia, arrhythmias.
- Neurological: Fatigue, confusion, visual disturbances.
- Electrolyte Imbalance: Hypokalemia increases toxicity risk.
