Schwarzbach, Anita Digitalis compounds are contraindicated in patients who are hypokalemic, or who have atrioventricular or Wolff-Parkinson-White (WPW) syndrome. Electrolyte abnormalities increase the risk of digoxin toxicity these include hypokalemia, hypercalcemia and hypomagnesemia therefore care should be taken when used in patients with electrolyte imbalances. 2000. These ions are on either side of the cell membranes in the heart muscle cells. Rechberger, Gerald N. Chilkur Balaji college of Pharmacy Since the appearance of Kofler's book Die Saponinein 1927, the field has undergone a most remarkable transformation. Digitalis compounds have a small direct diuretic effect on the kidneys, which is beneficial in heart failure patients. The classical definition of saponins is based on their surface activity; many saponins have detergent properties, give stable foams in water, show haemolytic activity, have a bitter taste and are toxic to fish (piscicidal). The nonsugar component is known as the AGLYCONE. Verapamil and diltiazem also increase the levels of digoxin. Knorr, Dietrich Digoxin is an antiarrhythmic drug. Kowalczyk, Mariusz These can be activated by enzyme hydrolysis, which causes the sugar part to be broken off, making the chemical available for use. For the heart muscle to contract there has to be an interplay between some amount of electrolytes, sodium ions, potassium ions, and calcium ions. Other effects include; Given that digoxin has a narrow therapeutic window, the incidence of arrhythmias is not an unlikely one. Saponins are high-molecular-weight glycosides, consisting of a sugar moiety linked to a triterpene or steroid aglycone. Diuretics indirectly interact with digoxin because of their ability to cause hypokalemia (low potassium levels). The steroid nucleus consists of four fused rings to which other functional groups such as methyl, hydroxyl, and aldehyde groups can be attached to influence the overall molecule's biological activity. The Na+/K+-ATPase also plays an active role in the membrane potential. and With a reduced conduction fewer impulses pass through the AV node to the ventricles eventually reducing the ventricular rate. It is very important that therapeutic plasma levels are not exceeded because digitalis compounds have a relatively narrow therapeutic safety window. Glycosides play numerous important roles in living organisms. Cardiac glycosides are a group comprising two main classes of compounds that differ in the structure of their aglycone as shown in Figure 1.Cardiac glycosides are either C23 or C24 steroids with a basic nucleus of cyclopentanoperhydro phenanthrene substituted at C17. Tolvaptan works to decrease the amount of sodium in your body. Later signs include disorientation, visual effects known as halos. Three sodium ions are exchanged for each calcium ion.