<p><strong>Digoxin</strong>: In normal healthy volunteers a single dose of carvedilol taken together with a single dose of digoxin resulted in significantly increased levels of digoxin 24 hours later. Patients with congestive heart failure stabilized on digoxin have been given carvedilol concomitantly without any adverse effects. Increased monitoring of digoxin is recommended when initiating, adjusting, or discontinuing the dose of carvedilol.<br />
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<strong>Rifampin</strong>: Pretreatment with rifampin resulted in a 60% decrease in Cmax and AUC.<br />
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<strong>Warfarin</strong>: Carvedilol did not alter the in vitro plasma protein binding of warfarin.<br />
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<strong>Clonidine</strong>: &beta;-receptor antagonists potentiate the pressor reaction which may follow the sudden withdrawal of treatment with clonidine although, in theory, the a-blocking action of carvedilol should modify the pressure rise.</p>