Drug Interaction Report

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.

GENERALLY AVOID: Concurrent acute use of barbiturates and ethanol may result in additive CNS effects, including impaired coordination, sedation, and death. Tolerance of these agents may occur with chronic use. The mechanism is related to inhibition of microsomal enzymes acutely and induction of hepatic microsomal enzymes chronically.

MANAGEMENT: The combination of ethanol and barbiturates should be avoided.