Drug Interaction Report

MONITOR: Alcohol may decrease the antidiuretic effect of vasopressin. Clinical studies found that plasma vasopressin levels often decrease during alcohol consumption and increase upon cessation of consumption. In addition, alcoholics were found to have a more pronounced decrease in plasma vasopressin levels when drinking and suppressed vasopressin levels even during alcohol withdrawal as compared to non-alcoholic individuals. The mechanism of this interaction is not fully understood.

MANAGEMENT: Patients should be advised to abstain from alcohol during vasopressin treatment. Hemodynamic monitoring is suggested for patients known to drink alcohol while receiving vasopressin.

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.