Drug Interaction Report

GENERALLY AVOID: The addition of a rauwolfia alkaloid to existing monoamine oxidase inhibitor (MAOI) therapy may result in profound excitation and/or a hypertensive reaction. The proposed mechanism is increased norepinephrine levels at adrenergic receptors due to both the inhibition of catecholamine metabolism by MAOIs and the release of catecholamines induced by rauwolfia alkaloids. Theoretically, this interaction should not occur if rauwolfia alkaloid therapy is initiated several days before the start of MAOI therapy. However, clinical data are limited.

MANAGEMENT: In general, rauwolfia alkaloids should not be administered to patients treated with MAOIs or other agents that possess MAOI activity (e.g., furazolidone, linezolid, methylene blue, procarbazine). At least 14 days should elapse between discontinuation of MAOI therapy and initiation of treatment with rauwolfia alkaloids.

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.