How does this medication work? What will it do for me?

Phenelzine belongs to a group of medications known as monoamine oxidase (MAO) inhibitors. This medication is used to treat depression. Depression is believed to be caused by imbalances in certain brain chemicals. This medication helps to rebalance these chemicals.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Each orange, biconvex, film-coated tablet engraved with "PD 270" contains phenelzine sulfate, equivalent to phenelzine base 15 mg. Nonmedicinal ingredients: croscarmellose sodium, edetate disodium, magnesium stearate, mannitol, opadry orange, and povidone simethicone emulsion. This medication does not contain gluten, lactose, paraben, sodium, sulfite, or tartrazine.

How should I use this medication?

The recommended adult dose is 45 mg to 90 mg daily in 3 divided doses near the beginning of therapy and reduced to a smaller dose after maximum benefit has been achieved.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take phenelzine if you:

  • are allergic to phenelzine or any ingredients of the medication
  • are going to undergo elective surgery requiring general anesthesia
  • are taking or have recently taken certain medications (see drug interactions section or ask your doctor or pharmacist)
  • have a condition known as pheochromocytoma
  • have a history of liver disease or abnormal liver function tests
  • have congestive heart failure

Phenylzine sulfate should not be taken in combination foods with a high tyramine content. In general, those taking this medication should avoid high protein foods in which aging or protein breakdown is used to increase flavour. In particular, avoid foods such as:

  • avocados (especially if overripe)
  • bananas (if used with the peel)
  • beer and wine
  • Bovril
  • canned figs
  • caviar
  • cheese (exceptions: cream cheese and cottage cheese)
  • chocolate
  • fermented meat (e.g., bologna, pepperoni, salami)
  • liver
  • pickled herring
  • pods of broad beans (fava beans)
  • raisins
  • sauerkraut
  • sour cream
  • soy sauce
  • yeast extracts such as Marmite®
  • yogurt

These foods should be avoided while taking the medication and for at least 2 weeks after stopping the medication.

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses.Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • constipation
  • dizziness
  • dizziness when moving from a sitting or lying to a standing position
  • drowsiness
  • dry mouth
  • fluid retention
  • sexual disturbances
  • sleep disturbances (including insomnia and oversleeping)
  • stomach disturbances
  • weakness and fatigue
  • weight gain

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • tremors, twitching, or other involuntary movements
  • yellow eyes or skin

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • seizures
  • symptoms of dangerously high blood pressure (also called a "hypertensive crisis"): headache (at the back of the head, may travel to the front), palpitations, neck stiffness or soreness, nausea, vomiting, sweating, fever, cold clammy skin, dilated (enlarged) pupils, sensitivity of eyes to light, change in heart rate, or chest pain

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Certain foods and beverages: Anyone taking phenelzine must avoid the following, and for 2 weeks after stopping the medication: pickled herring, liver, dry sausage (including Genoa salami, hard salami, pepperoni, and Lebanon bologna), broad bean pods (fava beans), sauerkraut, cheese (cottage cheese and cream cheese are allowed), yogurt, beer and wine, alcohol-free and reduced-alcohol beer and wine products, yeast extract, meat extract, and excessive amounts of chocolate or caffeine.

People being treated with phenelzine should also avoid any spoiled or improperly refrigerated, handled, or stored protein-rich foods such as meats, fish, and dairy products, including foods that may have undergone protein breakdown by aging, pickling, fermentation, or smoking to improve flavour.

Diabetes: If you have diabetes, your doctor should closely monitor your condition while you are taking phenelzine, as it may affect blood sugar control.

Epilepsy: If you have epilepsy, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Hypertensive crisis: The most serious reaction associated with taking phenelzine is the occurrence of severe high blood pressure. These reactions include some or all of the following symptoms:

  • dilated pupils and eye sensitivity to light
  • extremely fast or slow heart rate associated with constricting chest pain
  • headache at the back of the head which may travel to the front
  • nausea or vomiting
  • neck stiffness or soreness
  • palpitation
  • sweating (sometimes with fever and sometimes with cold, clammy skin)

If you have these symptoms, stop taking the medication and get immediate medical attention.

Identification: People taking phenelzine are encouraged to carry a card or other notification of the fact that they are taking this medication.

Other medications: Phenelzine interacts with a number of different medications. Therefore, be sure to tell any health care professional involved in your care of all the medications you are taking, including those that can be bought without a prescription. Always ask your pharmacist for help in choosing over-the-counter medications.

Surgery: If you are scheduled to undergo surgery, inform all of the health care professionals involved in your care that you are taking this medication. Ask your doctor when you should stop taking this medication before the surgery - usually this medication should be stopped at least 10 days before the operation.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if phenelzine passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Do not breast-feed while you are taking this medication.

Children: The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with this medication?

There may be an interaction between phenelzine and any of the following:

  • alcohol
  • amphetamines (e.g., dextroamphetamine)
  • anesthetics (general or local anesthetics)
  • antidiabetes medication (e.g., glyburide, insulin)
  • antihypertensives (medications that reduce blood pressure)
  • barbiturates (e.g., phenobarbital, secobarbital)
  • bupropion
  • buspirone
  • carbamazepine
  • citalopram
  • clomipramine
  • cocaine
  • cyclobenzaprine
  • dextromethorphan
  • disulfiram
  • dopamine
  • ephedrine
  • epinephrine
  • guanethidine
  • L-tryptophan
  • L-tyrosine
  • medications for Parkinson's disease (e.g., levodopa)
  • methyldopa
  • methylphenidate
  • narcotics (e.g., codeine, morphine, meperidine)
  • norepinephrine
  • other MAO inhibitors (e.g., moclobemide, tranylcypromine)
  • other medications that stimulate the sympathetic (fight or flight) nervous system (e.g., ingredients found in some cough and cold, allergy, sinus, appetite suppressant, or weight loss products)
  • phenylalanine
  • phenylephrine
  • pseudoephedrine
  • reserpine
  • rizatriptan
  • selective serotonin reuptake inhibitors (SSRIs; e.g., fluoxetine, paroxetine)
  • sumatriptan
  • trazodone
  • tricyclic antidepressants (e.g., amitriptyline, desipramine)
  • venlafaxine
  • zolmitriptan

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.