Pharm Unit 5-2

Front 1

Inotropic effect

Back 1

influences contractility or force of contraction

Front 2

+ Inotropic effect

Back 2

more force of contractility

Front 3

- Inotropic effect

Back 3

less force of contractility

Front 4

Chronotropic effect

Back 4

influences rate

+ : increase beats or faster rate
- : slower rate or less beats

Front 5

Dromotropic effect

Back 5

influences conduction through specialized conducting tissues (fibers)

Front 6

Cardiac Glycosides

Back 6

What is another word for Digitalis?

Front 7

functional refractory period

Back 7

A period when the heart cannot be stimulated to depolarize again.

Front 8

force

Back 8

Drugs may change the ______, rate, and rhythm of the heartbeat.

Front 9

digitalis

Cardiac Glycosides

Back 9

1. Class of chemicals with very similar chemical structures
a. all have sugar structural group
2. Some can be extracted from plants
a. Digoxin - (Lanoxin) - from white foxglove - builds toxic levels if renal failure
b. Digitoxin (Crystodigin) - from purple foxglove (Digitalis purpura)

WATER SOLUBLE

Front 10

digitalis

Back 10

Used chiefly for positive INOTROPIC action
But also affects rate (- chronotropic action)
And especially conduction (-dromotropic effect) in the heart.

What drug?

Front 11

Used chiefly for positive INOTROPIC action
But also affects rate (- chronotropic action)
And especially conduction (-dromotropic effect) in the heart.

Back 11

What are the actions that digitalis does to the heart?

Front 12

+ inotropic action
- chronotropic
- dromotropic

Back 12

What are the mechanisms of action for Digitalis (Cardiac Glycosides)?

Front 13

1.increases Ca++ release within cardiac muscle (stronger)
2.increases Ca++ ion movement into muscle (with slow conduction)
3.increases parasympathetic (vagal) tone***

Back 13

What are the mechanisms of Cardiac Glycosides?

Front 14

release
Ca++
vagal

Back 14

1.increases Ca++ _______ within cardiac muscle (stronger)
2.increases _____ ion movement into muscle (with slow conduction)
3.increases parasympathetic (______) tone***

Front 15

Congestive heart failure

Atrial flutter, fibrillation, or paroxysmal tachycardia

Back 15

What are the therapeutic uses for Cardiac Glycosides (digitalis)?

Front 16

congestive heart failure

Back 16

heart fails to pump adequate amount of blood

gigantic fluid overload + weak heart

Front 17

Enlarged heart

Pulmonary edema

Systemic edema

Failng kidney

Increased heart rate

Back 17

What are the symptoms of congestive heart failure?

Front 18

hypertension
rheumatic fever
myocardial infarction

Back 18

What are the causes of Congestive heart failure?

Front 19

Supportive treatment of congestive heart failure w/digitalis

Back 19

Decreased weight, increased physical activeity, and decreased Na intake, and treat hypertension if present.

Front 20

heart size decreased to normal

lower HR

diuresis

Back 20

When using Digitalis, What are the results (3) for congestive heart failure?

Front 21

Atrial flutter

Back 21

(therapeutic effect)

______ ______ (200-300 bpm) or fibrillation (more than 300 bpm) or paroxysmal tachycardia (irregular beats) - usually requires higher dose than treating CHF.

Front 22

vagal
muscarinic
refractory

Back 22

Atrial flutter (mechanism of action)

Increases ______ tone (a ________ effect) and directly depresses electrical conduction in atria and AV node. This protects ventricles from receiving too many stimuli and increases ________ period.

Front 23

worst
narrow

Back 23

Digitalis is frequently prescribed but has one of ______ margins of safety. _____ therapeutic index.

Front 24

Visual

Ventricular arrythmias

Back 24

What are the side effects of digitalis (cardiac glycosides)?

Front 25

Visual side effect for digitalis

Back 25

often single color vision (yellow or green tinged vision), white halos around objects, blurred or double vision.

Front 26

Ventricular arrythmias (side effects)

Back 26

If greatly decreases BP may cause dizziness or fainting.

Ventricular tachycardia
Ventricular fibrillations
AV block

Front 27

Ventricular tachycardia

Back 27

increased automaticity with more ectopic beats)

always dangerous and is found above moderate doses "bigeminy" - coupled beats indicates toxicity.

Front 28

Ventricular fibrillations

Back 28

most common cause of death in digitalis overdose

(ectopic beats set up competing refractory periods.)

Front 29

AV block

Back 29

ventricular rate decreases below 60 bpm and must take pulse regularly (due to - dromotropic effect - increased vagal tone slows impulses to ventricle.)

Front 30

1. Recent myocardial infarction
2. Ventricular tachycardia
3. Partial heart block
4. Cardioversion (electroshock)
5. Calcium admission
6. Potassium depletion
7. Renal and hepatic disorders or older patient

Back 30

What are the contraindications or cautions for digitalis (cardiac glycosides)?

Front 31

1. Recent myocardial infarction

Back 31

contraindication of digitalis

prone to developing arrythmias

digitalis may have additive or synergisticeffect and if failure present, will probably give anyway.

Front 32

2. Ventricular tachycardia

Back 32

contraindication of digitalis

may throw into fibrillation (increased ectopic foci and automaticity)

Front 33

3. Partial heart block

Back 33

contraindication of digitalis

may produce complete block

better choice is to implant artial pacing wires (may be done with local anesthetic)

Front 34

4. Cardioversion (electroshock)

Back 34

contraindication of digitalis

may cause fibrillation that will not respond to further shocks.

Front 35

5. Calcium admission

Back 35

contraindication of digitalis

Ca++ has synergistic effect with digitalis - toxic effect

Front 36

6. Potassium depletion

Back 36

contraindication of digitalis

e.g. due to some diuretics - increased toxicity

(need K+)

Front 37

ACE inhibitors
B blockers
Aldosterone blockers

Back 37

What are some (3) CHF alternatives?

Front 38

ACE inhibitors

Back 38

_____ _______ are now recommended first for cases of heart failure though digitalis and direutics are most often prescribed as well.

Front 39

B blockers

Back 39

___ ________ may decrease hospitalization and lower mortality.

Front 40

first
digitalis
diuretics

Back 40

ACE inhibitors are now recommended ______ for cases of heart failure though _________ and _________are most often prescribed as well.

Front 41

Aldosterone blockers

Back 41

produced peripherally in the heart and in major BV independent of adrenal aldosterone. Aldosterone directly induces collagen myopathy in heart muscle. Aldosterone stops reuptake of catecholagmines so it induces sympathetic arrythmias. Blocking both of these effects would be beneficial.