Cardiac Glycosides And Drugs For Cardiac Failure Question And Answers

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Cardiac Glycosides And Drugs For Cardiac Failure Important Notes

1. Digitalis

  • Digitalis Used in the treatment of congestive cardiac failure
  • Digitalis To control arrhythmias
  • Digitalis increases
    • Force of contraction
    • Decreases heart rate
    • Raises oxygen consumption
    • Depresses conduction system
  • Enhances potassium uptake and sodium excretion

Cardiac Glycosides And Drugs For Cardiac Failure Short Essays

Question 1. Therapeutic uses and adverse effects of digoxin.

Answer:

Digoxin is cardio glycoside obtained from seeds of strophanthus gratus.

Digoxin Uses:

1. Congestive cardiac failure (CCF)

  • Digoxin induces an increase in contractility which increases ventricular ejection

2. Cardiac arrhythmias.

  • Digoxin is used for controlling atrial fibrillation associated with CCF.
  • A parenteral administration may terminate arrhythmia by increasing vagal tone.

3. Used for initiation and maintenance.

  • Used in patients with severe left ventricular systolic dysfunction after initiation of ACE inhibitor and diuretic therapy.

Digoxin Adverse effects:

1. Cardiac effects.

  • Arrhythmias like extrasystoles, bradycardia, pulse bigeminy, and terminal ventricular fibrillation AV block.

2. GIT effects:

  • Nausea, vomiting, anorexia, abdominal pain.

3. CNS effects.

  • Headache, confusion, irritation, hallucinations, blurred vision, gynaecomastia, psychosis, disorientation, CTZ stimulation.

4. Other.

  • Mesenteric vasoconstriction, weakness, skin rashes hyperpnoea.

Read And Learn More: Pharmacology Question and Answers

Question 2. Side effects of digoxin and treatment.

Answer:

Digoxin Adverse Effects:

  • GIT effects
    • Nausea, vomiting, anorexia, abdominal pain
  • CNS effects
    • Headache, confusion, irritation, hallucination, blurred vision, Gynaecomastia, psychosis, disorientation, CTZ stimulation
  • Mesenteric contraction
  • Skin rashes
  • Hyperapnoea
  • Cardiac effects
  • Arrhythmias like extrasystoles, bradycardia, pulse bigeminy, terminally ventricular fibrillation AV block

Digoxin Treatment:

  • Stop administration of digoxin
  • Oral or parenteral administration of potassium supplements is given
  • Ventricular arrhythmias are treated with lidocaine
  • Atrial arrhythmias are treated by propranolol
  • Severe bradycardia/ AV block is treated with atropine

Cardiac Glycosides And Drugs For Cardiac Failure Short Answers

Question 1. Digitoxin.

Answer:

Digitoxin is obtained from leaves of digitalis purpurea.

Pharmacokinetics:

  • Given orally.
  • 90 – 100% is observed
  • The onset of action – 30 – 120 min.
  • Plasma half-life – 5 – 7 days.

Digitoxin Uses:

  • Cardiac arrhythmia.
  • Congestive cardiac failure.

Question 2. The rationale of using digoxin in atrial fibrillation.

Answer:

Digoxin decreases the number of impulses passing down the AV node and bundle of his.

  • Results in ventricular rate
  • Increases effective refractory period of AV node by direct vagomimetic and antiadrenergic action.
  • Thus, digoxin is used in atrial fibrillation.

Question 3. Cardiac toxicity of digoxin.

Answer:

Digoxin has a low safety threshold and a high incidence of adverse effects.

  • It produces cardiac toxicity characterized by arrhythmias, like extrasystoles, bradycardia, pulse bigeminy, and AV blocks.
  • It enhances hypokalemia.

Cardiac Toxicity of Digoxin Treatment:

  • Stop administration of digoxin.
  • Oral or parenteral administration of potassium supplements is given.
  • Ventricular arrhythmia – treated by lidocaine.
  • Atrial arrhythmias – treated with propranolol.
  • Severe bradycardia/A-V block – treated with atropine.

Cardiac Glycosides And Drugs For Cardiac Failure Viva Voce

  • Digitoxin is a cardiac glycoside
  • It is used in congestive cardiac failure
  • Calcium augments the ionotropic effect of digitalis

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