Drugs and HF

Question 1

What are the 5 pillars of heart failure ?

Answer 1

• Digoxin
• Loop/thiazide diuretic
• ACE
• Spironolactone
• B antagonist

Question 2

How does Digoxin work ?

Answer 2

Digoxin stimulates the force of contraction of heart muscle by inhibiting the Na/K ATP-ase enzyme

Question 3

How do furosemide and bumetandime work ?

What class of drugs are they ?

Answer 3

Loop diuretic

Both increase the urine flow by inhibiting the NKCC2 co-transporter in the ascending limb of the loop of Henle

Question 4

How do ACE inhibitors improve HF ? eg Enalapril

Answer 4

Enalapril, as in the Consensus study, was the first drug to be shown to reduce the probability of death in chronic heart failure, decreasing heart size, improving 1 year survival by 25% although with no effect on sudden death.

Question 5

Name a ARB

How do they help heart failure ?

Answer 5

Losartan
Candesartan

ARBs work by blocking receptors that the hormone acts on, specifically AT1 receptors, which are found in the heart, blood vessels and kidneys. Blocking the action of angiotensin II helps to lower blood pressure and prevent damage to the heart and kidneys.

Question 6

What class of medication is spironolactone ?

Answer 6

mineralocorticoid receptor antagonist

Question 7

What is the mechanism of action of spironolactone?

Answer 7

Spironolactone is a receptor antagonist of the steroid hormone aldosterone. Aldosterone increases sodium reabsorption and the renal secretion of potassium by the distal nephron; spironolactone interferes with this.

Spironolactone causes increased amounts of sodium and water to be excreted, while potassium is retained.

WORKS ON THE DCT COLLECTING DUCTS.