Heart failure drugs

Question 1

What is the definition of heart failure

Answer 1

heart is unable to pump sufficient blood to meet the metabolic demands of the body’s tissues
2 types:
1. Preserved ejection fraction: inability to relax
2. reduced ejection fraction
- in chronic heart failure due to ischemic reasons, there is death of myocytes, usually to compensate for lower output there would be sympathetics and raas activation to increase blood volume/ pressure filling. However, past a certain point due to cardiomyocyte damage it is unable to increase SV with any respective rise of filling pressure

No. 1 cause is due to conorary disease,
poor prognosis

Question 2

explain the edema symptoms of heart failure

Answer 2

when heart is failing/reduced cardiac output

• bp drops activating sympathetics and RAAS, increased sodium retention and water retention.
• reduced renal blood flow and increased venous pressure–> reduce GFR
• hence leads to edema,

Question 3

Classes of drugs for heart failure

Answer 3

ABD

+ vasodilators for ischemic attacks

Question 4

What is a vasodilator used in hypertensive/ acute coronary disease (crisis)

Answer 4

sodium nitroprusside

• intravenously
• short onset of action (minutes)

Question 5

Adverse effects of sodium nitroprusside

Answer 5

• Methemoglobin: can cause hypoxia
• cyanide: can cause posioning
• Hypotension
  contraindicated in pregnancy
  needs to be closely monitored

Question 6

Name 3 classes of diuretics and where they act

Answer 6

1. loop diuretic: furosemide, bumetaminde
2. Distal convoluted tubule: thiazides, hydrochlorothiazide
3. Potassium sparing diuretics:
   a. Spironolactone, eplerenone
   b. triamterene, amiloride

Question 7

Which parts of the nephron are water permeable

Answer 7

Ascending limb of loop of henle is almost impermeable to water, so is DCT. Most water is reabsorbed in the PCT, then collecting duct

Question 8

Name a loop diuretic and its MOA

Answer 8

furosemide, bumetaminde
Inhibits the Na/K/2Cl channel transporter on apical membrane of ascending limb, reduces absorption and hence decreasing the gradient for osmosis later on. Increases diuresis

Increases renal blood flow with PG
Inhibits the facilitation potassium leaking back into tubules, creating positive potential to cause Mg and other cation reuptake. Reduces cation reuptake

very quickly absorbed, duration 2-3 hrs, eliminated by tubular secretion

Question 9

Indication and adverse effect of loop diuretics

Answer 9

Indications: -Pulmonary edema congestive heart failure (volume overload), hyperkaelemia, kidney failure, anion toxicity

adverse effects: LOOP
Low mag, Ototox, gOut, Potassium low and pH high
otoxicity, hypomagnesia, hyperuricemia, hypokaelemic

Question 10

Name a thiazide and its moa

Answer 10

hydrochlorothiazide,
inhibits NaCl channel, decreases K+ reabsorption
Ca 2+ is actively reabsorbed
Hydrochlorothiazide will actually increase the calcium reabsorption

Question 11

Indications and adverse side effects of thiazides

Answer 11

indications:

1. fluid overload
2. Hypertension
3. Calcium caused nephrolithiasis
4. nephrogenic diabetes inspidus

Adverse effects:

1. hyponatremia
2. hyperlipidemia, and glycemia,
3. Hyperuricemia
4. hypokaelemia

Question 12

Name 2 types of potassium sparing diuretic and its MOA

Answer 12

aldosterone inhibitor: Spironolactone(takes days to take into effect), eplerenone
sodium channel inhibitor: amiloride(secreted in kidneys, longer half life), triamterene (shorter half life, metab by liver)
-na + reabsorption decreased
- K+ decrease secretion

Question 13

Indications and adverse effects of potassium sparing

Answer 13

• hypokaelemic diuretic
• hyperaldosteronism

Adverse effects:
SPARING
saved potassium acidosis renal insufficiency nephrolithiasis gynaecomastia
- hyperkaelemia
-metab acidosis
- gynaecomastia
- acute renal failure (triamterene+ indomethacin)
- kidney stone (triamterene)