Drug Interactions between brimonidine / dorzolamide / latanoprost / timolol ophthalmic and digoxin

MONITOR: Concomitant use of digitalis glycosides and beta-blockers may increase the risk of bradycardia. These agents slow atrioventricular conduction and decrease heart rate, hence they may have additive cardiac effects during coadministration. Some beta-blockers such as carvedilol, esmolol, and talinolol have also been reported to increase the systemic bioavailability of digoxin. The mechanism may involve enhanced absorption as well as reduced renal excretion of digoxin due to inhibition of intestinal and renal P-glycoprotein efflux transporter.

MANAGEMENT: Caution is advised during coadministration of digitalis glycosides and beta-blockers. Serum digitalis levels, heart rate, and blood pressure should be monitored closely, particularly during the first few weeks of concomitant therapy. Patients should be advised to notify their physician if they experience anorexia, nausea, visual changes, irregular heartbeat, slow pulse, dizziness, or syncope. Beta-blockers should not be used in patients with overt or decompensated congestive heart failure, as sympathetic stimulation may be a vital component in maintaining hemodynamic function in these patients and its inhibition by beta blockade may worsen the heart failure.

MONITOR: Topically administered alpha-2 adrenergic receptor agonists such as apraclonidine and brimonidine are systemically absorbed, with the potential for producing rare but clinically significant systemic effects such as hypotension and bradycardia. The possibility for an additive or potentiating effect on blood pressure and heart rate should be considered when used with other medications that affect these parameters, such as ophthalmic and systemic beta blockers, vasodilators, cardiac glycosides, and antihypertensive agents.

MANAGEMENT: Blood pressure and pulse rate should be monitored regularly when topical alpha-2 adrenergic receptor agonists are prescribed in combination with cardiovascular drugs. Patients should be advised to notify their physician if they experience slow pulse, irregular heartbeat, dizziness, lightheadedness, or syncope.

MONITOR: Topically administered alpha-2 adrenergic receptor agonists such as apraclonidine and brimonidine are systemically absorbed, with the potential for producing rare but clinically significant systemic effects such as hypotension and bradycardia. The possibility for an additive or potentiating effect on blood pressure and heart rate should be considered when used with other medications that affect these parameters, such as ophthalmic and systemic beta blockers, vasodilators, cardiac glycosides, and antihypertensive agents.

MANAGEMENT: Blood pressure and pulse rate should be monitored regularly when topical alpha-2 adrenergic receptor agonists are prescribed in combination with cardiovascular drugs. Patients should be advised to notify their physician if they experience slow pulse, irregular heartbeat, dizziness, lightheadedness, or syncope.