role of diuretics in the management of congestive heart failure

role of diuretics in the management of congestive heart failure

1. ROLE OF DIURETICS IN THE MANAGEMENT OF CONGESTIVE HEART FAILURE

2. DIURETICS A diuretic is any drug that elevates the rate of urination and thus provides a means of forced diuresis . These are the only drugs which produce rapid symptomatic effects in c.h.f conditions. They are used in combination with an ACE inhibitor and a β-blocker in order to optimize their effectiveness. They relieve the symptoms but donot cure the underlying cause.

3. Why are the diuretics used? Diuretics are used in the treatment of c.h.f because they:- Decrease preload and improve ventricular efficiency by reducing circulating volume. Removes peripheral edema and pulmonary congestion.

4. Reduced cardiac output Heart Failure Sympathetic nervous system activation Vasoconstriction Cardiac Remodeling Renin-angiotensin system Sodium and water retention Elevated cardiac filling pressure Diuretics

5. Diuretics used in the treatment of C.H.F Loop diuretics Thiazide diuretics K sparing diuretics

6. Loop diuretics These drugs have the highest efficacy in mobilizing water & Na + from the body. Furosemide , bumetanide , torasemide and ethacrynic acid are the four loop diuretics. Furosemide is the most commonly used loop diuretic.

7. Mechanism of action They inhibit the cotransport of Na + / K + / Cl - in the luminal membrane of ascending loop of henle . They are considered as the most efficacious as the ascending loop accounts for the reabsorption of 25 to 30% of the filtered NaCl

8. Therapeutic Use in c.h.f It is the drug of choice for rapid mobilization of edema fluid in moderate to severe cases of c.h.f .

9. Thiazide diuretics These are medium efficacy diuretics. They are also called ceiling diuretics because increasing the dose above normal does not promote a further diuretic response. Ex:- Hydrochlorothiazide, benzthiazide , hydroflumethiazide , clopamide .

10. Mechanism of action They inhibit the Na + / Cl - cotransport present on the luminal membrane of distal convoluted tubule. Therapeutic use in c.h.f They are used in the treatment of mild to moderate heart failure.

11. Adverse effects of loop & thiazide diuretics Hypokalaemia Dilutional hyponatraemia Git and cns symptoms Ototoxicity Hyperuricaemia Hypomagnesia Hyercalcaemia in thiazide whereas hyocalcaemia in loop diuretics

12. Spironolactone ( Aldosterone inhibitor) recent evidence suggests that it may improve survival in CHF patients due to the effect on renin-angiotensin-aldosterone system with subsequent effect on myocardial remodeling and fibrosis

13. K+ sparing diuretics

14. General effects They act as venodilators and, when giving intravenously, reduce right atrial and pulmonary capillary wedge pressure within minutes