Shop products for Phenelzine 
Phenelzine is a member of a group of drugs called monoamine oxidase (MAO) inhibitors (also called MAOIs). Phenelzine is sometimes used to treat people with depression who do not respond to other antidepressant drug therapy.
Summary of
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
interactions.
 May be Beneficial: Depletion or
interference—The medication may deplete or interfere with the absorption or
function of the nutrient. Taking these nutrients may help replenish them. |
Vitamin B6 |
 Avoid: Adverse interaction—Avoid these supplements
when taking this medication because taking them together may cause undesirable or dangerous
results. |
Aspartame* Ephedra* Ginseng (species not specified)* Scotch broom St. John’s wort* Tyramine-containing foods |
| Side effect reduction/prevention |
None known |
| Supportive interaction |
None known |
| Reduced drug absorption/bioavailability |
None known |
An asterisk (*) next to an item in the summary indicates that the interaction is supported only by weak, fragmentary, and/or contradictory scientific evidence.
Interactions with Dietary Supplements
Vitamin B6
Phenelzine has a chemical structure similar to other drugs (isoniazid and hydralazine)
that can cause vitamin B6 deficiency. One case of phenelzine-induced vitamin B6 deficiency has
been reported.1 Little is known about this interaction. People taking phenelzine
should ask their doctor about monitoring vitamin B6 levels and considering
supplementation.
Interactions with Herbs
Ephedra
Ephedra contains the chemical ephedrine, which may
interact with phenelzine, causing potentially dangerous changes to blood pressure.2
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.
Ginseng (species not specified)
In a case report of a woman treated with phenelzine, addition of a ginseng-containing tea was
associated with insomnia, headache, and
tremor.3 Other contents of the tea were not reported. In a case report of a woman
treated with phenelzine for depression, addition of
ginseng (not further identified) was associated with hypomania (a mild form of mania), which
the patient had not previously experienced.4 Until more is known, people should
combine ginseng and phenelzine with caution after consulting a knowledgeable doctor.
St. John’s
wort(Hypericum perforatum)
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.5 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.
Scotch broom (Cytisus scoparius)
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).6 It is
important for people taking phenelzine to avoid Scotch broom. People with questions about
phenelzine and Scotch broom should ask their doctor.
Interactions with Foods and Other Compounds
Tyramine-containing foods
Phenelzine can alter metabolism of a chemical called tyramine that is present in certain
foods, leading to diarrhoea, flushing, sweating,
pounding chest, dangerous changes in blood pressure, and other symptoms.7 It is
important for people taking phenelzine to avoid tyramine-containing foods. People with
questions about phenelzine and tyramine-containing foods should ask their doctor or
pharmacist.
Aspartame
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.8 Until more is known, people taking phenelzine should use
aspartame-containing foods with caution.
References
1. Heller CA, Friedman PA. Pyridoxine deficiency and peripheral neuropathy associated with long-term phenelzine therapy. Am J Med 1983;75:887–8.
2. Threlkeld DS, ed. Central nervous system drugs, antidepressants, monoamine oxidase inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Apr 1997, 264y.
3. Shader RI, Greenblatt DJ. Phenelzine and the dream machine-ramblings and reflections. J Clin Psychopharmacol 1985;5:65.
4. Jones BD, Runikis AM. Interaction of ginseng with phenelzine. J Clin Psychopharmacol 1987;7:201–2.
5. St. John’s wort, Hypericum perforatum. In American Herbal Pharmacopoeia and Therapeutic Compendium, ed. R Upton. Santa Cruz, CA: AHP, 1997.
6. Brinker F. Interactions of pharmaceutical and botanical medicines. J Naturopathic Med 1997;7(2):14–20.
7. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants, Monoamine Oxidase Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Apr 1997, 264y.
8. Shader RI, Greenblatt DJ. Phenelzine and the dream machine-ramblings and reflections. J Clin Psychopharmacol 1985:5:65.
