5. Drugs Used To Treat Congestive Heart Failure

Front 1

How can we reduce the symptoms associated with heart failure?

Back 1

By decreasing preload, decreasing after load, increasing myocardial contractility and inhibiting excessive compensatory catecholamine effects.

Front 2

Name cardiac glycosides

Back 2

Digoxin and digitoxin

Front 3

Effects of digoxin on heart?

Back 3

Increased contractility.

Decreased HR

Decreased AV conduction

Increased excitability

Front 4

Indications for digoxin?

Back 4

Atrial fibrillation or flutter with fast ventricular rate.

As supplementary in chronic heart failure where ACEIs, beta blockers and diuretics fail.

Front 5

Mechanism of action of digoxin?

Back 5

It inhibits the Na+/K+ ATPase. The increased IC Na+ will lead to Ca2+ influx. It makes also the sarcoplasmic reticulum release more Ca2+ into the cell. This leads to increased contractility.

It also stimulates the vagal nuclei and vagal nerves, causing low HR and lower AV-conduction.

Front 6

Side effects of digoxin?

Back 6

Positive excitability can lead to risk for ventricular extrasystoles and ventricular arrhythmias.

Nausea, vomiting, constipation (vagal stimuli)

Headache, confusion, hallucinations and disturbance of color vision (yellow hues are seen)

Front 7

Pharmacokinetics of digoxin and digitoxin?

Back 7

Orally absorbed and has 60 % plasma protein binding. (Digitoxin has 97 %)

They are both widely distributed in the body.

Digoxin is eliminated by renal excretion and digitoxin by the liver.

Front 8

Interactions with digoxin?

Back 8

Decreased renal function, decreased serum K+ and increased plasma Ca2+ can lead to intoxication.

Drugs like verapamil, amiodarone and propafenone increase the plasma concentration of digoxin by displacing it from plasma proteins, reducing digoxins excretion and releasing it from tissue stores.

Front 9

Contraindications of digoxin?

Back 9

In slow AV-conduction, sinus bradycardia, sick sinus syndrome, ventricular systole, WPW syndrome, hypertrophic cardiomyopathy, previous AMI or impaired kidney function.

Front 10

Name drugs that can increase the intracellular cAMP

Back 10

Dobutamine, dopamine, amrinone and milrinone.

Front 11

How do dobutamine and dopamine increase cAMP?

Back 11

They are strong b1-agonists. They bind to b1 adrenergic receptors and activate adenylyl cyclase, which produces more cAMP. The more cAMP, the more Ca2+, and the contractility increases.

Front 12

Indications for dobutamine and dopamine?

Back 12

Used in acute heart failure and cardiogenic shock where the goal is to reach increased contractility.

Front 13

How can amrinone and milrinone increase cAMP?

Back 13

They inhibit phosphodiesterase (PDE) so cAMP is not degraded intracellularly.

Front 14

Indications for amirinone and milrinone?

Back 14

Acute decompensated heart failures

Front 15

Name Ca2+ sensitizers

Back 15

Levosimendan

Front 16

The action of ca2+ sensitizers?

Back 16

They bind to troponin and make it more sensitive to Ca2+, which give same effect as increased Ca2+. Since they don't cause any change in ion flow, they don't increase the increase in energy demand of myocardium. They are not arrhythmic.

They also cause peripheral vasodilation.

Front 17

Indications of levosimendan?

Back 17

Acute decompensated heart failure as supplement because conventional therapy is not enough.

Front 18

Which drug classes are the most important in the treatment of heart failure?

Back 18

ACE inhibitors, loop diuretics, beta blockers, digitalis and nitrates.