Two cases were reported involving men treated with phenelzine who experienced restlessness, agitation, tremor, and insomnia after drinking large quantities of cola beverages containing aspartame. Until more is known, people taking phenelzine should use aspartame-containing foods with caution.

Ephedra contains the chemical ephedrine, which may interact with phenelzine, causing potentially dangerous changes to blood pressure. People should read product labels for ephedra/ephedrine content. Ephedra and ephedrine-containing products should be avoided during phenelzine therapy. People with questions about phenelzine and ephedra/ephedrine should ask their doctor or pharmacist.

This interaction is based on this drug belonging to a drug class. While this drug may differ from the text and references below, drugs within this class work in a similar way and this interaction is applicable to drugs within the same class.

Scotch broom contains high levels of tyramine. Combining phenelzine and Scotch broom may cause MAOI-type reactions (diarrhoea, flushing, sweating, pounding chest, dangerous changes in blood pressure, and other symptoms). It is important for people taking phenelzine to avoid Scotch broom. People with questions about phenelzine and Scotch broom should ask their doctor.

Although St. John’s wort contains chemicals that bind MAO in test tubes, it is believed that the action of St. John’s wort is not due to MAOI activity. However, because St. John’s wort may have serotonin reuptake inhibiting action (similar to the action of drugs such as Prozac®, it is best to avoid concomitant use of St. John’s wort with MAOI drugs.