DRUGS IS ACUTE CONGESTIVE HEART FAILURE

DRUGS USED IN ACUTE CONGESTIVE HEART FAILURE(CHF) 

In CHF there are two main problems

   1. Decrease in pumping activity of heart

   2.Accumulation of fluid (oedema) 

So for above pathology we use mainly to group of drugs 

    (1) Diuretics

    (2) Inotropics

I) DIURETIC

Usually in Acute CHF we have to rigorously remove accumulated fluid so LOOP DIURETICS ARE PREFERRED OVER THIAZIDES 

Loop diuretics

This are group of drugs act on the (NKCC2) in the thick ascending limb of the loop of henles to inhibit sodium, chloride and potassium reabsorption. This is achieved by competing for the Cl⁻ binding site. This reduces the hypertonicity of the renal medulla, inhibiting water reabsorption by the collecting ducts

 Thus this action decrease odema component in CHF Case

This group includes drugs like:

• Torosemide
• Ethacrynic acid
• Furosemide 

(2) INOTROPICS

Inotropics are group of drugs which increases pumping activity of heart 

 This category includes

1. Beta -1 agonist

2.Phosphodiesterase inhibitor

3.Digitalis 

BETA-1 AGONIST

This act on beta-1 receptor on heart directly thus increase in contractility of heart as well as heart rate 

This group includes:

Dopamine

Dobutamine

Noradrenaline

Isoprenaline

PHOSPHODIESTERASE INHIBITORS

Beta-1 agonist act on beta-1 receptor activates G protein which in turn increases cAMP this cAMP is destroyed by phosphodiesterase thus giving phosphodiesterase inhibitors causes rise in cAMP levels  so increases pumping activity of heart

This also causes Vasodilation in blood vessel 

Due to this both property of inotropics and Vasodilation they are called as INODIALATOR

 This phosphodiesterase inhibitors are DRUG OF CHOICE IN Right heart failure

This group includes:

1.Amirinone

2.Milirinone

DIGITALIS 

Digoxin is only clinically used drug in this category

The main mechanism of action of digitalis is on the Na+k+ ATPase of the myocyte. It reversibly inhibits the ATPase resulting in increased intracellular Na+ levels. The build-up of intracellular Na+ leads to a shift of Na+ extracellularly through another channel in exchange for Ca++ ions. This results in availability of more calcium ion in successive beat so more force of contractions in successive beat thus person on digitalis gets relief from symptoms after 3-4 week of digitalis treatment 

Addition to this digitalis causes vagal stimulation results in decrease in heart rate

UNLIKE BETA-1 AGONIST AND PHOSPHODIESTERASE INHIBITORS which increases heart rate and increase work on heart 

So DIGITALIS IS best drug in ACUTE CHF 

Digitalis should be closely monitored as risk of digitalis toxicity is high even at slight change in dose 

This is contraindicated in RENAL FAILURE 

NOTE:

Hypokalemia causes digitalis toxicity but digitalis toxicity causes hyperkalemia 

NEWER DRUG IN CHF

1. BNP( brain Nateuretic peptides) 

      Recombinant includes Neseritide

2.IVABRADIN

         Blocks sodium funny current

3.NEP inhibitors

            -Sacubitril

          -Ecadotril

4.VASOPEPTIDASE INHIBITORS

             -sampatrilat

           -omapatrilat

THIS ALL ABOVE TREATMENT IS FOR ACUTE CONGESTIVE HEART FAILURE!!!!!! 

                               

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