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

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.

ADJUST DOSING INTERVAL: Coadministration with beta-blockers may diminish the therapeutic effects of tasimelteon. Beta-blockers have been shown to reduce the production of melatonin via inhibition of beta-1 adrenergic receptors; therefore, the efficacy of tasimelteon, which acts as an agonist at melatonin MT1 and MT2 receptors, may be reduced.

MANAGEMENT: Product labeling for tasimelteon suggests avoiding the nighttime administration of beta-blockers.

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. Although the interaction has not been specifically studied, the possibility of an additive or potentiating effect with central nervous system (CNS) depressants such as alcohol, barbiturates, opiates, anxiolytics, sedatives, and anesthetics should be considered. Additive hypotensive effects and orthostasis may also occur with some CNS depressants and other agents that have these effects, particularly during initial dosing and/or parenteral administration.

MANAGEMENT: Patients receiving topical alpha-2 adrenergic receptor agonists in combination with agents that can cause CNS depression should be made aware of the potential for increased adverse effects such as drowsiness, dizziness, lightheadedness and confusion, and counseled to avoid activities requiring mental alertness until they know how these agents affect them. Patients should also avoid rising abruptly from a sitting or recumbent position and notify their physician if they experience orthostasis or tachycardia.