II. Indications: Comorbid Depression
- Anxiety Disorder
- Atypical Depression
- Refractory Depression
- Bulimia
- Social Phobia
III. Mechanism
- Inhibits monoamine oxidase
- Monoamine Oxidase is enzyme that breaks down biogenic amines (e.g. Norepinephrine, Serotonin, Dopamine)
- Type A Monoamine Oxidase affects Gastrointestinal System
- Type B Monoamine Oxidase affects Central Nervous System
- Older MAO inhibitors are nonspecific and affect both Type A and B (e.g. trancypromine, Phenelzine)
- Selegiline is specific for Type B and is used in Parkinsonism
- Increases synaptic concentration of monoamines
IV. Precautions
- Tyramine-free diet must be followed
- Continue for two weeks after stopping medication
- See Tyramine Containing Foods
- Stop 2 weeks before starting another Antidepressant
- Taper Nardil slowly when stopping
- See Antidepressant Withdrawal
- Reduce dose by 15 mg/day every 2 weeks (or 10%/week)
V. Preparations: Hydrazine
- Isocarboxazid (Marplan): No longer manufactured in U.S.
- Dosing: 10 mg PO bid
- Maximum: 60 mg per day
- Phenelzine (Nardil)
- Dosing: 15 mg PO tid
- Maximum: 90 mg per day
VI. Preparations Non-hydrazine
- Tranylcypromine (Parnate)
- Dosing: 10-40 mg/day in divided doses
- Maximum: 60 mg per day
- Parkinsonian agents
- Selegiline (Eldepryl)
VII. Preparations: Other agents with MAO inhibitor Activity
- Linezolid
-
St John's Wort
- Contains Hypericin and Hyperforin (weak Type A and B MAO inhibitors)
VIII. Complications
-
Hypertensive Crisis (life-threatening)
- Occurs if tyramine or Sympathomimetic exposure
- Treat with Phentolamine (alpha-adrenergic Antagonist)
-
Hypotension to cardiovascular collapse (occurs with Overdose)
- Treat with Intravenous Fluids and direct acting Vasopressors (e.g. Norepinephrine)
-
Serotonin Syndrome
- Occurs with concurrent use of other Serotoninergic drug, or in Overdose
IX. Drug Interactions (Do not use with these medications)
X. Adverse Effects
- Anti-Histaminergic effects
- Dizziness
- Sedation
- Orthostatic Hypotension
- Weight gain
-
Dopaminergic effects
- Insomnia
- Myoclonal jerks
- Serotoninergic Effects
-
Anticholinergic Toxicity
- Dry Mouth
- Constipation
- Blurred Vision
- Urinary hesitancy
- Nausea
- Memory Dysfunction
- Other Effects
- Peripheral Edema
- Weakness
XI. References
- Nordt and Shoenberger in Herbert (2019) EM:Rap 19(3): 8-9
Images: Related links to external sites (from Bing)
Related Studies
phenelzine (on 9/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
PHENELZINE SULFATE 15 MG TAB | Generic | $0.57 each |
tranylcypromine (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
TRANYLCYPROMINE SULF 10 MG TAB | Generic | $0.89 each |