[The past and present of cardiac glycosides. II. Structure, physical and chemical properties. Pharmacodynamics].
An outline is presented on the physical and chemical properties and structure of the most important cardiac glycosides, i.e. digoxin, digitoxin and g-strophanthin. The overall effects of cardiac glycosides on the cardiovascular system not only are a composite of changes in the force of ventricular contraction and heart rate but also result from effects on the autonomic nervous system and on vascular smooth muscle. Furthermore reflex adjustments to the initial hemodynamic changes caused by the drug are also important. In the normal heart and circulation cardiac glycosides increase inotropy and decrease the chronotropy and dromotropy of the heart. They increase the peripheral vascular resistance and venous tone. Cardiac output remains unchanged or decreases slightly owing to increased peripheral vascular resistance and slowed heart rate. In patients with compromised cardiac inotropy the effects of the glycosides on the heart is essentially the same as in normal subjects, however by suppressing the enhanced sympathetic activity the negative chronotropic and dromotropic effects are more prominent. Peripheral vascular resistance is lowered, cardiac output and venous capacity are increased.
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D002301:Cardiac Glycosides / Q000493:pharmacokinetics / Q000494:pharmacology; D055598:Chemical Phenomena; D002621:Chemistry; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans
D002301:Cardiac Glycosides
Minulost a soucasnost srdecních glykozidů. II. Struktura, fyzikální a chemické vlastnosti. Farmakodynamika.