Drug Interaction Report

CONTRAINDICATED: Tetrabenazine may cause excitation and hypertension in patients treated with monoamine oxidase inhibitors (MAOIs). The proposed mechanism has not been fully established but may be related to interference with biogenic amine storage. In addition, tetrabenazine may have depressant effects and may exacerbate depression. The same interaction can be expected for deutetrabenazine, a deuterium-containing analog of tetrabenazine.

MANAGEMENT: Concurrent administration of tetrabenazine and deutetrabenazine with MAOIs or other agents that possess MAOI activity (e.g., furazolidone, linezolid, methylene blue, procarbazine) is considered contraindicated. At least 14 days should elapse between discontinuation of MAOI therapy and initiation of treatment with either tetrabenazine or deutetrabenazine, and vice versa.

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.