Classifications: psychotherapeutic; antidepressant; monoamine oxidase inhibitor (maoi);
Therapeutic: antidepressant
; maoi
Prototype: Phenelzine
Pregnancy Category: C


10 mg tablets


Potent nonhydrazine MAO inhibitor. Antidepressant activity arises from the increased availability of monoamines resulting from the inhibition of the enzyme MAO. Reduction of MAO activity results in an increased concentration of neurotransmitters, such as epinephrine, norepinephrine, and dopamine in the CNS.

Therapeutic Effect

Drug of last choice for severe depression unresponsive to other MAO inhibitors.


Severe depression.


Patients >60 y; confirmed or suspected cerebrovascular defect, cardiovascular disease, CHF; history of hepatic disease; hypertension, pheochromocytoma, history of severe or recurrent headaches; acute MI; alcoholism; angina; renal failure; suicidal ideation; anuria; pregnancy (category C); lactation.

Cautious Use

Bipolar disorder; Parkinson's disease; psychosis; schizophrenia; seizure disorders; history of suicidal attempts.

Route & Dosage

Severe Depression
Adult: PO 30 mg/d in 2 divided doses (20 mg in a.m., 10 mg in p.m.), may increase by 10 mg/d at 3 wk intervals (max: 60 mg/d)


  • Crush tablet and give with fluid or mix with food if patient cannot swallow pill.
  • Note: Usually not given in the evening because of possibility of insomnia.

Adverse Effects (≥1%)

CNS: Vertigo, dizziness, tremors, muscle twitching, headache, blurred vision. CV: Orthostatic hypotension, arrhythmias, hypertensive crisis. GI: Dry mouth, anorexia, constipation, diarrhea, abdominal discomfort. Skin: Rash. Urogenital: Impotence. Body as a Whole: Peripheral edema, sweating.


Drug: tricyclic antidepressants, fluoxetine, amphetamines, ephedrine, reserpine, guanethidine, buspirone, methyldopa, dopamine, levodopa, tryptophan may precipitate hypertensive crisis, headache, or hyperexcitability; alcohol and other cns depressants add to CNS depressant effects; meperidine can cause fatal cardiovascular collapse; anesthetics exaggerate hypotensive and CNS depressant effects; metrizamide increases risk of seizures; diuretics and other antihypertensive agents add to hypotensive effects. Food: Tyramine-containing foods may precipitate hypertensive crisis (e.g., aged cheeses, processed cheeses, sour cream, wine, champagne, beer, pickled herring, anchovies, caviar, shrimp, liver, dry sausage, figs, raisins, overripe bananas or avocados, chocolate, soy sauce, bean curd, yeast extracts, yogurt, papaya products, meat tenderizers, broad beans). Herbal: Ginseng, ephedra, ma huang, St. John's wort may lead to hypertensive crisis; ginseng may lead to manic episodes.


Absorption: Completely absorbed from GI tract. Onset: 10 d. Metabolism: Rapidly metabolized in liver to active metabolite. Elimination: Primarily in urine. Half-Life: 2.5 h (but may take 120 h for urinary tryptamine levels to return to normal).

Nursing Implications

Assessment & Drug Effects

  • Monitor BP closely. Incidence of severe hypertensive reactions appears to be greater with tranylcypromine than with other MAO inhibitors.
  • Monitor for changes in behavior that could indicate increased suicidality.
  • Expect therapeutic response within 3 d, but full antidepressant effects may not be obtained until 2–3 wk of drug therapy.

Patient & Family Education

  • Do not eat tyramine-containing foods (see FOOD–DRUG INTERACTIONS).
  • Be aware that excessive use of caffeine-containing beverages (chocolate, coffee, tea, cola) can contribute to development of rapid heartbeat, arrhythmias, and hypertension.
  • Make position changes slowly, particularly from recumbent to upright posture.
  • Avoid potentially hazardous activities until response to drug is known.
  • Avoid alcohol or other CNS depressants because of their possible additive effects.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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