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phenelzine (fen-el-zeen)



Therapeutic: antidepressants

Pharmacologic: monoamine oxidase (MAO) inhibitors


Treatment of neurotic or atypical depression (usually reserved for patients who do not tolerate or respond to other modes of therapy [e.g., tricyclic antidepressants, SSRIs, SSNRIs, or electroconvulsive therapy]).


Inhibits the enzyme monoamine oxidase, resulting in an accumulation of various neurotransmitters (dopamine, epinephrine, norepinephrine, and serotonin) in the body. Therapeutic Effects: Improved mood in depressed patients.

Adverse Reactions/Side Effects

CNS: SEIZURES, dizziness, drowsiness, fatigue, headache, hyperreflexia, insomnia, tremor, twitching, weakness, euphoria, paresthesia, restlessness. EENT: blurred vision, glaucoma, nystagmus. CV: HYPERTENSIVE CRISIS, edema, orthostatic hypotension. GI: constipation, dry mouth, abdominal pain, liver function test elevation, nausea, vomiting. GU: sexual dysfunction, urinary retention. Derm: pruritus, rashes. F and E: hypernatremia. Endo: weight gain.


Examination and Evaluation

  • Be alert for new seizures or increased seizure activity, especially at the onset of drug treatment. Document the number, duration, and severity of seizures, and report these findings immediately to the physician.

  • Measure blood pressure (BP) periodically and compare to normal values (See Appendix F). Immediately report a large, rapid increase in BP (hypertensive crisis). Signs and symptoms of hypertensive crisis include chest pain, tachycardia or bradycardia, severe headache, nausea, vomiting, neck stiffness, sweating, and enlarged pupils. The risk of hypertensive crisis is increased when this drug is taken with other antidepressants, excessive caffeine, other drugs that increase BP, or foods that contain tyramine (e.g., fermented wines, cheeses).

  • Be alert for increased depression and suicidal thoughts and ideology, especially when initiating drug treatment or in children and teenagers. Notify physician or mental health professional immediately if patient exhibits worsening depression.

  • Be alert for anxiety, euphoria, severe restlessness, or other alterations in mental status. Notify health care professional if these symptoms become problematic.

  • Assess BP when patient assumes a more upright position (lying to standing, sitting to standing, lying to sitting). Document orthostatic hypotension and contact physician when systolic BP falls >20 mm Hg or diastolic BP falls >10 mm Hg.

  • Assess peripheral edema using girth measurements, volume displacement, and measurement of pitting edema (See Appendix N). Report increased swelling in feet and ankles or a sudden increase in body weight due to sodium retention (hypernatremia) and fluid retention.

  • Assess paresthesias (numbness, tingling), tremor, or increased reflex activity. Perform objective tests including electroneuromyography and sensory testing to document any drug-related neuropathic changes.

  • Assess dizziness and drowsiness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

  • Periodically assess body weight and other ...

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