Mode of action of digoxin || Pharmacology ||Anurag Gupta & Anasmoinuddin

2. INTRODUCTION of C.H.F.
It is a pathophysiological chronic progressive disorder
where the heart is not able to pump sufficient amount
of blood required by the metabolic demand of the
body.
 Impaired ability to fill or eject blood
 Abnormal increase in blood volume
 Arteriosclerotic heart disease
 Myocardial heart disease
 Long standing hypertension
 Valvular heart disease

3. MAIN CAUSE
 Systole dysfunction
 Diastole dysfunction
 Role of physiological compensatory mechanism

4. DIGOXIN
It is cardiac glycoside used to treat various heart
conditions such as Arterial fibrillation , arterial
flutter and heart failure.
R.O.A- Oral & I.V
Therapeutic range- 0.8 ng/ml
Toxicity range > 2.4 ng/ml
Metabolism -16% Liver

5. Ca2+
Ca2+Ca2+
Ca2+ Ca2+
Ca2+Ca2+
Ca2+
Ca2+Ca2+
Ca2+
Ca2+Ca2+
Ca2+
Ca2+
Ca2+
Ca2+ ATPase
3Na+
3Na+
Low[Na+]
High[Na+]
2K+
Na+/K+ pump
Na+/Ca2+
exchanger
Ryanodine
receptor Ca2+
Muscle
contraction
L type Ca+2 channel

6. When Na+ level
fall
Sarcoplasmic
reticulum Inactive
Causes low level
of Ca2+
Get exhausted and
fail to work
C.H.F.
Leads to weak
myocardial systole
This causes
accumulation of blood in
ventricles
Leads to weak
myocardial distention
Heart tries to expel this
accumulated blood
volume
Pathophysiology

7. Ca2+
Ca2+Ca2+
Ca2+
Ca2+
Ca2+Ca2+
Ca2+
Ca2+Ca2+
Ca2+
Ca2+Ca2+
Ca2+
Ca2+
Ca2+
Ca2+ ATPase
3Na+
3Na+
Low[Na+]
High[Na+]
2K+
Na+/K+ pump
Na+/Ca2+
exchanger
Ryanodine
receptor Ca2+
Muscle
contraction
Ca2+Ca2+
Ca2+ Ca2+
Ca2+Ca2
+
Ca2+
Ca2+
Ca2+Ca2
+
Ca2+Ca2+Ca2
+
Ca2+
L type Ca2+ channel

8. M.O.A. Of Digoxin
Digoxin
Blocks Na+/K+ ATPase
Pump
Now more of Ca2+
pumped into S.R.
through Ryanodine
receptor
Increase Na+ level
intracellularly
Now it lowers the activity of
Na+/ca2+ exchanger to
remove Ca2+
Action potential travels
Ca2+ influx -open L-
type channel

9. Ca2+ bind to Ryanodine
receptor
Lots of Ca2+ inside S.R. Relieves Congestion
Now S.R. activates and
causes forceful contraction
Leads to complete emptying of
Heart (ventricles)
Restore myocardial
function

10. Adverse effect of digoxin
 CARDIAC EFFECT = Arrythmia(Tachycardia) , Hypokalemia
 GIT EFFECT = Anorexia , Nausea , Vomiting , Diarrhea
 CNS EFFECT = Headache , Fatigue , Blurred vision

11. DATA ANALYSIS

13. Cyanide