II. Indications: Comorbid Depression

III. Mechanism

  1. Inhibits monoamine oxidase
    1. Monoamine Oxidase is enzyme that breaks down biogenic amines (e.g. Norepinephrine, Serotonin, Dopamine)
    2. Type A Monoamine Oxidase affects Gastrointestinal System
    3. Type B Monoamine Oxidase affects Central Nervous System
    4. Older MAO inhibitors are nonspecific and affect both Type A and B (e.g. trancypromine, Phenelzine)
    5. Selegiline is specific for Type B and is used in Parkinsonism
  2. Increases synaptic concentration of monoamines
    1. Serotonin
    2. Norepinephrine

IV. Precautions

  1. Tyramine-free diet must be followed
    1. Continue for two weeks after stopping medication
    2. See Tyramine Containing Foods
  2. Stop 2 weeks before starting another Antidepressant
  3. Taper Nardil slowly when stopping
    1. See Antidepressant Withdrawal
    2. Reduce dose by 15 mg/day every 2 weeks (or 10%/week)

V. Preparations: Hydrazine

  1. Isocarboxazid (Marplan): No longer manufactured in U.S.
    1. Dosing: 10 mg PO bid
    2. Maximum: 60 mg per day
  2. Phenelzine (Nardil)
    1. Dosing: 15 mg PO tid
    2. Maximum: 90 mg per day

VI. Preparations Non-hydrazine

  1. Tranylcypromine (Parnate)
    1. Dosing: 10-40 mg/day in divided doses
    2. Maximum: 60 mg per day
  2. Parkinsonian agents
    1. Selegiline (Eldepryl)

VII. Preparations: Other agents with MAO inhibitor Activity

  1. Linezolid
  2. St John's Wort
    1. Contains Hypericin and Hyperforin (weak Type A and B MAO inhibitors)

VIII. Complications

  1. Hypertensive Crisis (life-threatening)
    1. Occurs if tyramine or Sympathomimetic exposure
    2. Treat with phentolamine (alpha-adrenergic Antagonist)
  2. Hypotension to cardiovascular collapse (occurs with Overdose)
    1. Treat with Intravenous Fluids and direct acting Vasopressors (e.g. Norepinephrine)
  3. Serotonin Syndrome
    1. Occurs with concurrent use of other Serotoninergic drug, or in Overdose

IX. Drug Interactions (Do not use with these medications)

X. Adverse Effects

  1. Anti-Histaminergic effects
    1. Dizziness
    2. Sedation
    3. Orthostatic Hypotension
    4. Weight gain
  2. Dopaminergic effects
    1. Insomnia
    2. Myoclonal jerks
  3. Serotoninergic Effects
    1. Sexual Dysfunction
    2. Headache
  4. Anticholinergic Toxicity
    1. Dry Mouth
    2. Constipation
    3. Blurred Vision
    4. Urinary hesitancy
    5. Nausea
    6. Memory Dysfunction
  5. Other Effects
    1. Peripheral Edema
    2. Weakness

XI. References

  1. Nordt and Shoenberger in Herbert (2019) EM:Rap 19(3): 8-9

Images: Related links to external sites (from Bing)

Related Studies

Cost: Medications

phenelzine (on 5/17/2017 at Medicaid.Gov Survey of pharmacy drug pricing)
PHENELZINE SULFATE 15 MG TAB Generic $0.48 each
nardil (on 6/1/2017 at Medicaid.Gov Survey of pharmacy drug pricing)
NARDIL 15 MG TABLET Generic $0.48 each
tranylcypromine (on 5/17/2017 at Medicaid.Gov Survey of pharmacy drug pricing)

Ontology: Phenelzine (C0031392)

Definition (CSP) monoamine oxidase inhibitor used to treat depression and phobic disorders.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D010624
SnomedCT 387528000, 9500005
LNC LP17998-3, MTHU024864
English 2 Phenethylhydrazine, 2-Phenethylhydrazine, Fenelzin, Phenelzine, Phenethylhydrazine, beta Phenylethylhydrazine, beta-Phenylethylhydrazine, phenelzine, Hydrazine, (2-phenylethyl)-, Phenelzine [Chemical/Ingredient], fenelzin, PHENELZINE, MAOI - Phenelzine, Phenelzine (product), Phenelzine (substance)
Swedish Fenelzin
Czech fenelzin
Finnish Feneltsiini
Japanese フェネルジン
Italian beta-Feniletilidrazina, Fenelzina
Spanish fenelcina, fenelzina (producto), fenelcina (producto), fenelcina (sustancia), fenelzina (sustancia), fenelzina, Fenelzina, Fenelzin
Polish Nardil, Fenelzyna
French Phénelzine
German Fenelzin, Phenelzin
Portuguese Fenelzina

Ontology: Tranylcypromine (C0040778)

Definition (MSH) A propylamine formed from the cyclization of the side chain of amphetamine. This monoamine oxidase inhibitor is effective in the treatment of major depression, dysthymic disorder, and atypical depression. It also is useful in panic and phobic disorders. (From AMA Drug Evaluations Annual, 1994, p311)
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D014191
SnomedCT 372891006, 89092006
LNC LP14552-1, MTHU001574
English trans-2-Phenylcyclopropylamine, Tranylcypromine, trans 2 Phenylcyclopropylamine, Cyclopropanamine, 2-phenyl-, trans-(+-)-, tranylcypromine, SKF 385, Tranylcypromine [Chemical/Ingredient], TRANYLCYPROMINE, MAOI - Tranylcypromine, Tranylcypromine (product), Tranylcypromine (substance)
Swedish Tranylcypromin
Czech tranylcypromin
Finnish Tranyylisypromiini
Japanese トラニルシプロミン
Polish Tranylcypromina
Spanish tranilcipromina (producto), tranilcipromina (sustancia), tranilcipromina, Tranilcipromina
French Tranylcypromine
German Tranylcypromin
Italian Tranilcipromina
Portuguese Tranilcipromina

Ontology: Nardil (C0701388)

Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D010624
English nardil, Nardil, Parke Davis Brand of Phenelzine Sulfate, Pfizer Brand of Phenelzine Sulfate, United Drug Brand of Phenelzine Sulfate

Ontology: Parnate (C0701426)

Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D014191
English parnate, Parnate, Allphar Brand of Tranylcypromine Sulfate, GlaxoSmithKline Brand of Tranylcypromine Sulfate, Goldshield Brand of Tranylcypromine Sulfate, Link Brand of Tranylcypromine Sulfate, SmithKline Brand of Tranylcypromine Sulfate