Pharmacology

Question 1

What are the compensatory mechanisms in heart failure ?

Answer 1

1- Renin-angiotensin-aldosterone system
2-sympathetic nervous system
3- neuro-humoral mechanisms such as secretion of bradykinin

Question 2

Vasodilators - ACE inhibitors

Answer 2

ACEI lower the preload and afterload by blocking the synthesis of A2
such as Enalapril, ramipril ad lisinopril.
no parenteral formulations
used in chronic left or biventricular heart failure

Question 3

adverse effects of ace inhibitors:

Answer 3

Renal failure
due to increased bradykinin levels: -chronic cough and angioedema
hypotension

Question 4

Is ACEI used in patients with chronic heart failure ( diastolic )?

Answer 4

No, they’re only used in patients with systolic heart failure where the ejection fraction is reduced, it helps in reducing mortality and prolonging the life

Question 5

ACEI contractions?

Answer 5

Renal artery stenosis
Aortic stenosis “ increases resistance across the aortic valve “
Angioedemas
pregnancy

Question 6

A2 receptor antagonists

Answer 6

Competitive antagonists of A2 can also be called angiotensin receptor blockers

Question 7

A2 receptor antagonists/ARB’S

Answer 7

Does not produce cough, mostly used for hypertension
examples are; losartan, candesartan ( for hf also), and irbesartan.
decreases afterload

Question 8

Nitrates

Answer 8

symptom relief:
Glyceryl trinitrate (short-acting) - sublingual
also treats angina
Isosorbide (longer action)
all-cause the release of nitric oxide that would induce smooth ms. relaxation = reduced venous return

Question 9

Nitrates side effects

Answer 9

if its IV:
dose-related hypotension
if its tablets:
Headache
can be used in combination with hydralazine when intolerant to ACEI

Question 10

Loop Diuretics

Answer 10

A symptom relief

• Inhibits the Na 2cl K+ pump in the thick ascending loop of Henle.
• decreases blood volume and preload, additional time for the heart to relax.
  example: furosemide> at high concentrations can act as a vasodilator

Question 11

Loop diuretics side effects :

Answer 11

Dehydration can develop into shock.
Hypokalemia
Hyperuricemia and gout
ototoxicity
reduced glucose tolerance
**they're actually effective in renal function so avoid adding impaired renal function as a side effect :)

Question 12

Diuretics ( Thiazides) are used for what mainly?

Answer 12

Hypertension

Question 13

Diuretics ( Thiazides) mechanism of action ?

Answer 13

Acts on the distal tubule prevent the reabsorption of 3 to 5% of filtered Na+
examples: Bendroflumethiazide & Metolazone.

Question 14

Side effects of the Thiazides are:

Answer 14

Hypokalemia
Hyperurecimia and gout
Reduced glucose tolerance
Impotence
Renal failure

Question 15

Aldosterone antagonists

Answer 15

Reduces mortality in patients with reduced ejection fraction.

Question 16

Aldosterone antagonists

Answer 16

these agents antagonize the activity of aldosterone. Therefore, they will result in retention of K+ and excretion of NA+
in combination with the loop or thiazide classes for additive diuretic effect and to prevent hypokalaemia.

Question 17

Aldosterone antagonists

Answer 17

Spironolactone is an aldosterone antagonist that has a similar structure to Progesterone. Hence, other than the fact that they block androgen receptors preventing the formation of androgens, they also bind to the progesterone receptors causing Gynaecomastia in men and menstrual irregularities in women.
Eplerenone has lesser side effects

Question 18

When used with ACEI , hyperkalemia occurs as a side effect?

Answer 18

Aldosterone antagonists

Question 19

Beta-Blockers

Answer 19

Negative inotropes, decrease the force of contractility of the heart and worsens the heart failure
reduces mortality with diuretics and ACEI

Question 20

Examples of Beta-blockers

Answer 20

Carvedilol, Bisoprolol, Metoprolol and Nevivolol

Question 21

When are Beta-blockers given?

Answer 21

If a patient is newly diagnosed, we wait until he is decongested and treated with symptom relief and then we can start the beta-blockers.
**Notice that once the beta-blockers are given you never never never withdraw them from the patient even if he has acute heart failure symptoms!

Question 22

Ionotropic drugs

Answer 22

used to increase the force of ventricular contraction when myocardial systolic function is impaired. They enhance cardiac contraction by increasing the intracellular calcium concentration, thus augmenting actin and myosin interactions.
stroke volume and cardiac output are increased.

Question 23

Ionotropic drugs example

Answer 23

Dobutamine

Question 24

ionotropic drugs

Answer 24

These drugs are commonly used after large MI with a Cardiogenic Shock.
These drugs are also associated with high mortality rates.
These drugs are administered only when the net clinical benefit is positive.
- Low BP, poor renal/splanchnic perfusion, acute renal failure.

Question 25

Dobutamine

Answer 25

• Dobutamine is given I.V. with a very short half-life. Therefore, infusion rate
determines plasma concentration.
• With lower infusion rates, increased contractility and CO will be noticed.
• With higher infusion rates, arterial constriction and tendency to reduce
splanchnic perfusion

Question 26

Oral inotropes

Answer 26

Digoxin

Question 27

Digoxin is

Answer 27

symptom relief, oral inotrope