VA Class:CN602
AHFS Class:
- Monoamine Oxidase Inhibitors 28:16.04.12
Generic Name(s):
Phenelzine sulfate is a monoamine oxidase (MAO) inhibitor antidepressant.
Major Depressive Disorder 
Phenelzine is used in the treatment of major depressive disorder.100,101 Phenelzine has been found to be effective in patients with depression clinically characterized as atypical, nonendogenous, or neurotic (these patients often have mixed anxiety and depression and phobic or hypochondriacal features); there is less conclusive evidence that the drug is useful in severely depressed patients with endogenous features.100 Because of the potential for serious adverse effects, monoamine oxidase (MAO) inhibitors (e.g., phenelzine, tranylcypromine) generally are not used as initial therapy in the management of depression, but are reserved for patients who do not respond adequately to other antidepressant agents (e.g., selective serotonin-reuptake inhibitors [SSRIs], tricyclic antidepressants) or in whom other therapies are contraindicated.100,101 (See Uses in the Monoamine Oxidase Inhibitors General Statement 28:16.04.12.) Patient response to antidepressant agents is variable, and patients who do not respond to one drug may be successfully treated with a different agent.
Eating Disorders
Phenelzine has been used with some success in the management of bulimia nervosa†.102,103 However, MAO inhibitors potentially are dangerous in patients with chaotic binge eating and purging behaviors and the American Psychiatric Association (APA) states that MAO inhibitors should be used with caution in the management of bulimia nervosa.102 For information on diagnosis and treatment of bulimia nervosa and other eating disorders, see Uses: Eating Disorders, in Fluoxetine Hydrochloride 28:16.04.20.
Administration
Phenelzine sulfate is administered orally.
Dosage
Dosage of phenelzine sulfate is expressed in terms of phenelzine.
Patients should be monitored for possible worsening of depression, suicidality, or unusual changes in behavior, especially at the beginning of therapy or during periods of dosage adjustment.104,105,106 (See Worsening of Depression and Suicidality Risk under Cautions: Precautions and Contraindications, in the Monoamine Oxidase Inhibitors General Statement 28:16.04.12.)
Major Depressive Disorder
Dosage of phenelzine must be carefully adjusted according to individual requirements and tolerance, using the lowest possible effective dosage. The usual initial adult dosage of phenelzine for the treatment of depressive disorder is 15 mg 3 times daily. Subsequent dosage during early treatment should be increased fairly rapidly to at least 60 mg daily, depending on the patient's tolerance and therapeutic response. Dosages up to 90 mg daily may be required in some patients to obtain sufficient inhibition of monoamine oxidase (MAO). After maximum benefit is obtained, usually in 2-6 weeks, dosage should be slowly reduced over a period of several weeks to a maintenance level. Dosage during prolonged maintenance therapy may be as low as 15 mg daily or every other day.
Phenelzine shares the toxic potentials of other MAO inhibitors, and the usual precautions and contraindications associated with these drugs should be observed. Patients should be fully advised about the risks, especially hypertensive crisis and suicidal thinking and behavior (suicidality), associated with MAO inhibitor therapy.100,104,105,106,107 For a complete discussion, see Cautions in the Monoamine Oxidase Inhibitors General Statement 28:16.04.12.
Pediatric Precautions
Safety and efficacy of phenelzine in pediatric patients have not been established.100
The US Food and Drug Administration (FDA) has determined that antidepressants increase the risk of suicidal thinking and behavior (suicidality) in children and adolescents with major depressive disorder and other psychiatric disorders.104 However, FDA also states that depression and certain other psychiatric disorders are themselves associated with an increased risk of suicide.104 Anyone considering the use of phenelzine in a child or adolescent for any clinical use must balance the potential risk of therapy with the clinical need.100,104,106,107 (See Cautions: Precautions and Contraindications and Cautions: Pediatric Precautions, in the Monoamine Oxidase Inhibitors General Statement 28:16.04.12.)
Pharmacology
The principal pharmacologic effects of phenelzine are similar to those of other MAO inhibitors (e.g., tranylcypromine).
For a complete discussion on the pharmacology of phenelzine, see the Monoamine Oxidase Inhibitors General Statement 28:16.04.12.
Chemistry and Stability
Chemistry
Phenelzine sulfate is a monoamine oxidase (MAO) inhibitor antidepressant agent. The drug is a hydrazine derivative. Phenelzine sulfate occurs as a white to yellowish white powder with a characteristic odor and is freely soluble in water and practically insoluble in alcohol.
Stability
Commercially available phenelzine sulfate tablets should be stored in tight containers at a temperature between 15-30°C; the tablets should be protected from excessive exposure to heat and light.
Additional Information
For further information on chemistry, pharmacology, uses, cautions, acute toxicity, drug interactions, and dosage and administration of phenelzine, see the Monoamine Oxidase Inhibitors General Statement 28:16.04.12.
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
Phenelzine Sulfate
Routes | Dosage Forms | Strengths | Brand Names | Manufacturer |
|---|
Oral | Tablets, film-coated | 15 mg (of phenelzine) | Nardil® | Pfizer |
AHFS® Drug Information. © Copyright, 1959-2024, Selected Revisions January 1, 2009. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, MD 20814.
† Use is not currently included in the labeling approved by the US Food and Drug Administration.
100. Parke-Davis. Nardil® (phenelzine sulfate) tablets prescribing information. New York, NY; 2007 Aug.
101. American Psychiatric Association. Practice guideline for the treatment of patients with major depressive disorder (revision). Am J Psychiatry . 2000; 157(Suppl 4):1-45.
102. American Psychiatric Association. Practice guideline for the treatment of patients with eating disorders (revision). Am J Psychiatry . 2000; 157(Suppl 1):1-39.
103. Rothschild R, Quitkin HM, Quitkin FM et al. A double-blind placebo-controlled comparison of phenelzine and imipramine in the treatment of bulimia in atypical depressives. Int J Eat Disord . 1994; 15:1-9. [PubMed 8124322]
104. Food and Drug Administration. Antidepressant use in children, adolescents, and adults: class revisions to product labeling. Rockville, MD; 2007 May 2. From the FDA web site. [Web]
105. Food and Drug Administration. FDA news: FDA proposes new warnings about suicidal thinking, behavior in young adults who take antidepressant medications. Rockville, MD; 2007 May 2. From the FDA web site. [Web]
106. Food and Drug Administration. Revisions to medication guide: antidepressant medicines, depression and other serious mental illnesses and suicidal thoughts or actions. Rockville, MD; 2007 May 2. From the FDA web site. [Web]
107. Bridge JA, Iyengar S, Salary CB. Clinical response and risk for reported suicidal ideation and suicide attempts in pediatric antidepressant treatment: a meta-analysis of randomized controlled trials. JAMA . 2007; 297:1683-96. [PubMed 17440145]