[Interaction between calcium antagonists and digoxin]

Therapeutic uses of calcium antagonists have expanded to include not only ischemic heart disease but arrhythmias, systemic hypertension, congestive heart failure and various pulmonary and gastrointestinal diseases. Many patients receiving calcium antagonists concomitantly receive digoxin. Although the potential interactions between these agents have frequently been investigated, literature reports are confusing and inconsistent. The pharmacokinetics and mechanisms of interaction are summarized in order to help clinicians to evaluate the potential calcium antagonist digoxin interaction. From the investigations to date, changing the digoxin dosage prior to initiating calcium antagonist therapy is, however, not justifiable. The best approach would be to monitor pharmacodynamic values, SDC, and the patient's clinical status.