Techniques for studying the pharmacodynamic effects of cardiac glycosides on patients' own erythrocytes during glycoside therapy.
We have measured the effects of digoxin on the cation transport mechanisms of patients' erythrocytes during treatment with digoxin for atrial fibrillation and cardiac failure in sinus rhythm. The results show that during short-term treatment with digoxin there is occupation of erythrocytic cardiac glycoside receptors by digoxin with resultant inhibition of active cation transport. These effects correlate well with the patients' clinical responses to treatment. During long-term treatment, however, these effects are not seen, suggesting that there is pharmacological tolerance to the effects of digoxin. The clinical implications of these results are discussed.
D001281:Atrial Fibrillation / Q000097:blood / Q000188:drug therapy*; D004077:Digoxin / Q000097:blood / Q000627:therapeutic use*; D004573:Electrolytes / Q000097:blood; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism; D006333:Heart Failure / Q000097:blood / Q000188:drug therapy*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007473:Ion Channels / Q000187:drug effects*; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood
D004573:Electrolytes; D007473:Ion Channels; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase