Drug Interaction Report

GENERALLY AVOID: Cocaine exerts an indirect sympathomimetic effect and may precipitate hypertensive reactions and hyperpyrexia in patients treated with monoamine oxidase inhibitors (MAOIs), as has been reported with other indirect- or mixed-acting sympathomimetic agents such as amphetamine and ephedrine. The mechanism involves a synergistic effect due to enhanced norepinephrine storage in adrenergic neurons (MAOI activity) and decreased reuptake of catecholamines (indirect sympathomimetic activity). Headache, blood pressure increases, palpitations, and chest tightness were reported in two patients who used cocaine while receiving phenelzine for cocaine addiction. Increased serotonergic activity may also occur. An interaction resulting in unconsciousness, tremors, and muscle rigidity was suspected in a patient on phenelzine therapy who received 1 mL of a 10% cocaine spray to his vocal chords prior to surgery.

MANAGEMENT: In general, indirect-acting sympathomimetic agents such as cocaine should not be used concurrently 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 sympathomimetic agents.