Phenelzine

Phenelzine

Drug monograph · NCLEX study reference
Trade names	Nardil
Therapeutic class	Antidepressant
Pharmacologic class	Monoamine oxidase inhibitor (MAOI)
Onset / peak / duration	Mood effect over weeks.
Half-life / level	Enzyme inhibition outlasts the drug; level not routine.
Routes	PO (oral)
High-alert (ISMP)	No
Black box warning	Yes (see Safety)
Antidote / reversal	Phentolamine for hypertensive crisis; supportive care.
Pregnancy / lactation	Generally avoided.

Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.

Phenelzine (brand name Nardil) — Antidepressant; Monoamine oxidase inhibitor (MAOI).

Identification

• Therapeutic class: Antidepressant.
• Pharmacologic class: Monoamine oxidase inhibitor (MAOI).

Pharmacology

• Mechanism of action: Inhibits monoamine oxidase, increasing norepinephrine, serotonin, and dopamine.
• Onset / peak / duration: Mood effect over weeks.
• Half-life / therapeutic level: Enzyme inhibition outlasts the drug; level not routine.

Clinical use

• Indications: Treatment-resistant or atypical depression.
• Usual dose, route, frequency: PO divided doses.
• Maximum dose / adjustments: Allow a 2-week washout before and after other serotonergic drugs.

Safety

• Contraindications: Use with SSRIs, SNRIs, TCAs, sympathomimetics, meperidine, and many others; pheochromocytoma.
• Black box warning: Suicidality in those under 25.
• Interactions: Tyramine-rich foods (aged cheese, cured meats, fermented products, draft beer) cause hypertensive crisis; serotonergic drugs (serotonin syndrome), many decongestants and stimulants.
• Pregnancy / lactation: Generally avoided.
• High-alert: No.

Adverse effects

• Common side effects: Orthostatic hypotension, dizziness, insomnia, weight gain.
• Serious effects to report: Hypertensive crisis (severe headache, palpitations, neck stiffness), serotonin syndrome.
• Antidote / reversal: Phentolamine for hypertensive crisis; supportive care.

Nursing process

• Assessment before administration: Diet teaching, concurrent drugs, blood pressure, mood.
• Interventions during therapy: Reinforce strict tyramine-free diet and drug avoidance; observe washout periods.
• Monitor: Blood pressure, mood, diet adherence.
• Evaluation / expected outcome: Improved mood.

Patient teaching

• Patient teaching: Avoid tyramine foods and many over-the-counter cold and diet products; carry a list.
• Notify provider if: Severe or sudden headache, palpitations, neck stiffness, agitation with fever.
• Administration tips: Strict diet and drug avoidance; washout periods essential.