What is the difference between Digitalis and Digoxin

Cardiac Glycosides—

Synthesized from the plant carbohydrate by hydrolysis. It has sugar and non-sugar parts. These are the glycosidic compounds with cardiotonic action. They have— 1. Steroid nucleus & Lactone ring (non-sugar part)

2. Sugar moiety

*** the steroid nucleus contains Cyclo-Pentano Phenanthrene (CPP) ring

*** if the sugar part is glucose then it is called glycoside. (fructose—fructoside, pentose—pentoside)

*** sugar part = glycone part, lactone ring +CPP ring = Aglycone part.

Ø Pharmacokinetic property depends upon sugar moiety glycone part. Ø Pharmacodynamic property depends upon glycine moiety /aglycone part. Source of cardiac glycosides— - Digitalis lanata (Digoxin) - Digitalis purpura (Digitoxin) - Stropanthus gratus (Stropanthin) - Stropanthus kombe (Ouabian) Name of the Cardiac glycosides— 1. Digoxin (most commonly used) 2. Digitoxin 3. Ouabian *** Digitalis—Digoxin and Digitoxin Pharmacokinetics— Digitalis may be given as tablets or capsules Therapeutic index is very low so, low safety margin Wide distribution to various tissues because of lipid solubility

{Advantage—reaches the target site very quickly, Disadvantage—goes to other tissues} Digoxin mainly eliminated by the kidney (may be given to patients with liver diseases) Digitoxin is mainly eliminated by hepatic metabolism (may be given to patients with renal failure) The presence of enzyme inducers or inhibitors can change the extent of digitalis clearance

Digoxin is the only available preparation of digitalis in the United States. Digitalis is a plant-derived cardiac glycoside commonly used in the treatment of congestive heart failure (CHF), atrial fibrillation, and reentrant supraventricular tachycardia. While one has more toxic effects they are the "same drug"