Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include: other antidepressants (including maprotiline, mirtazapine, nefazodone, TCAs such as amitriptyline/nortriptyline), appetite suppressants (such as diethylpropion), drugs for attention deficit disorder (such as atomoxetine, methylphenidate), apraclonidine, bupropion, buspirone, carbamazepine, cyclobenzaprine, deutetrabenazine, dextromethorphan, certain drugs for high blood pressure (such as guanethidine, methyldopa, beta blockers such as atenolol, clonidine, rauwolfia alkaloids), other MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine), metoclopramide, certain opioid medications (such as fentanyl, meperidine, methadone, tapentadol), certain drugs for Parkinson's (such as entacapone, levodopa, tolcapone), street drugs (such as LSD, mescaline), stimulants (such as amphetamines, cocaine, dopamine, epinephrine, phenylalanine), tetrabenazine, "triptan" migraine drugs (such as sumatriptan, rizatriptan), tramadol, tyrosine, tryptophan, valbenazine.

The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/ "ecstasy," St. John's wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.

Tell your doctor or pharmacist if you are using any of these medications before, during, or within 2 weeks after treatment with phenelzine. Tell your doctor or pharmacist if you have taken fluoxetine during at least 5 weeks before starting phenelzine. Discuss with your doctor how much time to wait between starting or stopping any of these drugs and taking phenelzine.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy, cough-and-cold products, decongestants, diet pills) because they may contain dextromethorphan, decongestants, stimulants, or ingredients that cause drowsiness. Ask your pharmacist about the safe use of those products.

It is very important that you follow special dietary restrictions in order to limit the amount of tyramine in your diet. Avoid drinking large amounts of beverages containing caffeine (coffee, tea, colas) or eating large amounts of chocolate. Caffeine can increase the side effects of this medication. Foods and beverages high in tyramine should be avoided while you are taking this medication and for at least 2 weeks after you stop using this medication.

Foods high in tyramine include: aged cheeses (cheddar, camembert, emmenthaler, brie, stilton blue, gruyere, gouda, brick, bleu, roquefort, boursault, parmesan, romano, provolone, liederdranz, colby, edam), aged/dried/fermented/salted/smoked/pickled/processed meats and fish (includes bacon, summer sausage, liverwurst, hot dogs, corned beef, pepperoni, salami, bologna, ham, mortadella, pickled or dried herring), banana peel, beef/chicken liver (stored, not fresh), bouillon cubes, commercial gravies, concentrated yeast extracts, fava beans, Italian green beans, broad beans, fermented bean curd, homemade yeast-leavened bread, kim chee (Korean fermented cabbage), orange pulp, overripe or spoiled fruits, packaged soups, red wine, sauerkraut, sherry, snow pea pods, sourdough bread, soy sauce, soybeans, soybean paste/miso, tofu, tap beer and ale, vermouth.

Moderate-to-low tyramine content foods include: alcohol-free beer, avocados, bananas, bottled beer and ale, chocolate and products made with chocolate, coffee, cola, cultured dairy products (such as buttermilk, yogurt, sour cream), distilled spirits, eggplant, canned figs, fish roe (caviar), green bean pods, pate, peanuts, port wine, raisins, raspberries, red plums, spinach, tomatoes, white wine.

Tell your doctor or pharmacist right away if you notice symptoms of high blood pressure such as fast/slow heartbeat, vomiting, sweating, headache, chest pain, sudden vision changes, weakness on one side of the body, or trouble speaking.

Contact your healthcare professionals (such as doctor, pharmacist, dietician) for more information, including recommendations for your diet.