Inotropic agents glycosides

There is no doubt that the aforementioned glycosides are the most satisfactory inotropic compounds. However, digitahs drugs can be counter productive in some patients for a number of reasons. Theophylhne has been intensively studied as an inotropic agent however, it turned out to be unfit for long-term use. 

Agents that increase myocardial contraction force (positive inotropic agents] Digitalis glycosides... 

Examples of specific drugs used in the treatment of chronic heart failure include digitalis glycosides (e.g., digoxin, positive inotropic agent), diuretics (hydrochlortiazide and furosemide), and vasodilators (nitrates such as nitroglycerin, ACE inhibitors, such as captopril, and hydralazine). 

MOA Digoxin (cardiac glycoside) is a positive inotropic agent that inhibits the Na+/K+ ATPase pump. Inhibition of the pump causes an increase in intracellular sodium that allows the Na+/Ca exchanger to increase intracellular calcium. The heart is then able to use the increased intracellular calcium to increase contractility. 

Digitalis glycosides are positive inotropic agents used in the management of patients with congestive heart failure. They control ventricular rate in supraventricular arrhythmias including atrial fibrillation and atrial flutter. 

V. Drug or laboratory interactions. The positive inotropic effects of inamrinone are additive with other inotropic agents, including digitalis glycosides. These drugs can be used together, but the patient should be monitored for cardiac dysrhythmias. 

Milrinone is a member of a new class of bipyridine inotropic/vasodilator agents with phosphodiesterase inhibitor activity. It is a positive inotrope and vasodilator, with little chronotropic activity, different in structure and mode of action from either the digitalis glycosides or catecholamines (see also Figures 23 and 42). 

Dilantin appears to be the most effective agent used for arrhythmias due to digitalis toxicity. When used in combination with digitalis, dilantin reduces the toxic effects while the positive inotropic action of the glycoside remains °. 

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