Heart Contractility Drugs

Question 1

Mechanism of contraction of cardiomyocyte

Answer 1

Basics ez game

Question 2

Positive ionotropes
Effect:
Indications:
1-
2-
3-
4-

Answer 2

Increase cardiac contractility and output
1-decompensated congestive heart failure
2-cardiogenic shock
3-septic shock
4-cardiomyopathy

Question 3

Positive ionotropes:
1-
2-
3-

Answer 3

1-catecholamines(dopamine,epi,nor)
2- glucosides (digoxin)
3-PDE inhibitors

Question 4

Digitalis:
Effect:
MOA:
Use:

Answer 4

Increase contractility (postive iono)
Used in Hf
Influence Na/Ca flows in cardiac muscle

Question 5

T or F
Digitalis have narrow therapeutic index

Answer 5

True

Question 6

T or F
Digitals inhibits the Na/Ca channel directly

Answer 6

False
It inhibits the Na/K exchange by Na/K ATPase

Question 7

Usage of digoxin;

Answer 7

Heart failure with Atrial fib

Question 8

The difference between digoxin and digitoxin:
Absorption
Lipisolubility
Binding to proteins
T1/2
Delay of action

Answer 8

Kelun l digitoxin akbr

Question 9

T or F
Digoxin is mainly excreted renally

Answer 9

True laanu more hydrophilic
Unlike digitoxin le bydhar aktr she by bile la2anu lipophilic

Question 10

Adverse effects of digitalis:
1-
2-
3-

Answer 10

1-cardiac effects(arrythmia,slowing down AV conduction (brady and AVB),tachy)
2-GI effects (anorexia,vomiting,nausea,diarrhea)
3-CNS (headache,confusion,hallucinations,blurred vision)

Question 11

Severe toxicity : ventricular tachy
Dosage:
What do we do?

Answer 11

> 2ng/ml
Administration of antiarrythmic drugs
Antobodies to digoxin
Discontinuation

Question 12

Drug drug interaction:
—-,—,—- cause increased digoxin concentration
—-,—-,—– decrease potassium levels therefore—–

Answer 12

Quinidine,verapamil and amiodarone
(Displace digoxin from protein binding site and compete for renal excretion)

Conrtico
Thiazide
Loop therefore increase cardiotoxicity

Question 13

Sympathomimetic amines
Names:
1-
2-
3-
4-
5-
Use:

Answer 13

1-epi
2-norepi
3-dopamine
4-dobutamine
5-isoprotenerol

Anaphylactic shock,acute HF,cardiogenic shock and severe hypo

Question 14

Dopamine:
Cardiovascular effect:
1-
2-
Renal and visceral:

Answer 14

1-act on B1 increases ionotropy and chrono
2-at high conc act on a1 therefore induce vasocons

Increase blood flow to kidney and viscera

Question 15

Uses of dopamine:
1-
2-
3-

Answer 15

-for shock, increase cardiac output
-increase resistance (a1)
-increase BF to kidney which enhances GFR (unlike nor) and cause sodium diuresis

Question 16

Adverse effects of dopamine:

Answer 16

Nausea,hypertesion and arrythmias

Question 17

Dobutamine:
Fam:
Uses:
Adverse:

Answer 17

B1 agonist (increase cardiac output with little vascular effects)
Congestive HF + ionotropic support after cardiac surgery
Adverse: same as epi and tolerance on prolonged use

Question 18

cAMP is broken down by the enzyme—–
Ihibition of this enzyme prevents—- and increases —-,—-and—– of the heart

Answer 18

PDE3
cAMP breakdown
Chronotropy, inotropy and dromo

Question 19

Effects of PDE3 inhubitors:
1-
2-

Answer 19

Cardiac stimulation= increase cardiac output
Lowering vascular resistance

Question 20

Because of the dual cardiac and vascular effects of PDE inhibitors are referred to as —–

Answer 20

Inodilators

Question 21

Therapeutic indications of PDE inhibitors:
1-
2-

Answer 21

Acute HF
Acute decompensated HF

Question 22

Names of PDE inhibitors: with respective half lives
1-
2-

Answer 22

Milrinone(0.5-1 hr)
Inamrinone (2-3 hrs)

Question 23

Side effects and contraindications:
1-
2-

Answer 23

Chronic HF
Ventricular arrythmias
Headaches and hypotension