Drug Interaction Report

MONITOR: Coadministration of opioids with anticholinergic agents may result in additive central nervous system (CNS), gastrointestinal, and genitourinary effects. The risk and/or severity of adverse effects such as sedation, dizziness, confusion, cognitive and psychomotor impairment, dry mouth, constipation, and urinary retention may increase. Severe constipation may lead to paralytic ileus in some cases.

MANAGEMENT: Caution and close monitoring of central nervous system, gastrointestinal, and genitourinary adverse effects are recommended when opioids are used with anticholinergic agents. Ambulatory patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

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: Ethanol may potentiate the central nervous system (CNS) depressant effects of opioid analgesics. Concomitant use may result in additive CNS depression and impairment of judgment, thinking, and psychomotor skills. In more severe cases, hypotension, respiratory depression, profound sedation, coma, or even death may occur.

MANAGEMENT: Concomitant use of opioid analgesics with ethanol should be avoided.

GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.