Tranylcypromine (Parnate)

Tranylcypromine is a non-specific monamine oxidase inhibiting antidepressant (MAOI). It is marketed in the US by Glaxo-Smith-Kline as Parnate and is available as a generic medication.

The Bottom Line: What You Really Need to Know

Uses of tranylcypromine

Tranylcypromine is used to treat depression. Several types of depression respond to tranylcypromine, such as major depression without melancholia, anergic atypical depression, involutional melancholia, reactive depression and psychoneurotic depression. Tranylcypromine is sometimes also used to treat post traumatic stress disorder and panic disorder.

Tranylcypromine is not a "first line" medication, but is reserved to treat conditions that do not respond to other medications.

Dosage and instructions

The initial dose for tranylcypromine is usually 30 mg/day in divided doses (15 mg twice a day or 10 mg three times a day). Improvement may be seen in as little as 48 hours, or it may take up to three weeks. The dose is increased by 10 mg/day at intervals of 1-3 weeks until the desired effect is achieved. The maximum recommended dose is 60 mg/day.

The dose of tranylcypromine should be reduced in people who have liver disease and in children and elderly people.

How tranylcypromine works

Tranylcypromine inhibits an enzyme complex called monamine oxidase, which has multiple effects all over the body. One of the things MAO does is break down neurotransmitters like serotonin, dopamine and norepinephrine. Depletion of these neurotransmitters is thought to cause depression, anxiety and compulsions. Inhibition of MAO allows these substances to accumulate, relieving the symptoms.

Tranylcypromine is broken down in the liver and excreted in urine. Most of the drug is excreted within 24 hours, but the effects of MAO inhibition persist for several days.

Side Effects

Some of the side effects associated with tranylcypromine are:


One of the things that make tranylcypromine undesirable as a first line medication is the fact that it has serious interactions with many medications and foods. Some of these interactions could be fatal; it is extremely important to make sure your physician and pharmacist know about all medications that you take, including herbal remedies, over-the-counter medications, medications you only take occasionally, homeopathic or alternative treatments, herbal teas, etc.

Food: Foods that contain the amine acid tyramine can cause a hypertensive crisis when you are taking tranylcypromine. Tyramine is found in many foods, especially those that are aged, like cheese and wine. Chocolate and caffeine-containing beverages contain tyramine, too. Make sure you know which foods you should avoid while you are taking tranylcypromine.

Medications: Many medications interact with tranylcypromine and the interactions that can occur include hypertensive crisis, serotonin syndrome (a condition similar to neuroleptic malignant syndrome), blood sugar abnormalities and seizures. Some of the medications that should not be taken while you are taking tranylcypromine include:


You should not stop taking tranylcypromine abruptly. Severe withdrawal symptoms (agitation, nervousness, tremors and jerking, seizures, chills, etc) can occur. Tranylcypromine should be tapered gradually over several weeks before you stop taking it.

Warnings, precautions and contraindications

Suicide risk: There seems to be an increased risk for suicide with all antidepressants, especially in the first weeks or months of therapy. Anyone who starts taking an antidepressant should be monitored closely for at least several weeks. Report any unusual thoughts or feelings, anxiety, restlessness, worsening depression or other symptoms to your doctor immediately.

Manic episodes: Tranylcypromine can trigger severe mania and rapid cycling in people with bipolar disorder. Extreme anxiety, restlessness, aggression, altered thinking and psychosis can result. Violent behavior can occur. People should be screened for bipolar disorder before beginning tranylcypromine.

Hypertensive crisis: A serious interaction that can occur with tranylcypromine and certain foods or medications is hypertensive crisis. Blood pressure can become extremely high very rapidly and can result in a heart attack or stroke.

Serotonin syndrome and neuroleptic malignant syndrome: Serotonergic medications, such as other antidepressants, tryptophan, dextromethorphan and others, can cause these toxic disorders when you are taking tranylcypromine. They symptoms overlap and it may be difficult to differentiate them. Symptoms can begin with sweating, tremors and muscle jerking, agitation and restlessness. They can progress to very high fevers (106°F or higher), seizures, muscle rigidity, cardiovascular collapse, multiple organ failure and death.

Syncope: Some people who are taking 30 mg/day or more experience severe dizziness and fainting, especially when they stand up, related to very low blood pressure. It's important to monitor blood pressure frequently when taking tranylcypromine.

Elderly people: Elderly people do not have the physiogical reserves necessary to tolerate severe side effects, and can have much worse outcomes than younger people. Tranylcypromine should be used with caution in the elderly and dosage should be decreased.

Pregnancy: Tranylcypromine has been associated with birth defects when taken during the first trimester of pregnancy. It is excreted in milk and is not recommended for breast-feeding women.

Diabetes: Tranylcypromine can cause alterations in blood sugar in people who are taking diabetic medications.


Tranylcypromine is contraindicated (should not be used) in the following situations:

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