Possible Interaction: Adrenergic Beta-Antagonists and Digitalis

“After administration of digitalis together with a β-blocking agent the systolic and end-diastolic pressures of the right ventricle as well as the pulmonary artery wedged pressure during exercise were significantly lower than after β-blockade alone.”

“These findings indicate that digitalis eliminates the negative inotropic effect of a β-blocking agent but leaves the negative chronotropic effect unchanged.”

“This case report is the first to describe induction of amiodarone-associated "torsade de pointes" tachycardia during concomitant beta-blocker and digitalis medication in a patient with atrial fibrillation and structural heart disease.”

“Recent placebo-controlled randomized studies … that the addition of beta-blockers in stabilized, optimally pretreated patients with chronic heart … using angiotensin converting enzyme (ACE) inhibitors, diuretics and digitalis , is accompanied by an additional absolute decrease in mortality by about 5% and a relative decrease in mortality by about 35%.”

“These findings indicate that digitalis partially counteracts the elevation of filling pressures induced by beta-blocking agents but leaves CO unchanged.”

“7 Reduction of the sympathetically stimulated contractile force ofthe muscle is the least important of all the beta-blocking effects, but patients with advanced myocardial failure should be fillly digitalized-remembering that beta-blockers have a synergistic effect with digitalis in slowing the heart rate in atrial fibrillation.”