PHENELZINE

brands

Class

• Neuroscience-based Nomenclature: serotonin, norepinephrine, dopamine enzyme inhibitor (SN-EI)
• Monoamine oxidase inhibitor (MAOI)

PHENELZINE commonly prescribed for

(Bold for FDA approved)

How PHENELZINE works

• Irreversibly blocks monoamine oxidase (MAO) from breaking down norepinephrine, serotonin, and dopamine

• This boosts noradrenergic, serotonergic, and dopaminergic neurotransmission

How long until PHENELZINE works

• Onset of therapeutic actions usually not immediate, but often delayed 2–4 weeks following adequate dosing

• If it is not working within 6–8 weeks, it may require a dosage increase or it may not work at all

• May continue to work for many years to prevent relapse of symptoms

Notable Side Effects

• Dizziness, sedation, headache, sleep disturbances, fatigue, tremor

• Constipation, dry mouth, nausea, change in appetite, weight gain

• Sexual dysfunction (may be highest of any MAOI)

• Orthostatic hypotension (dose-related); syncope may develop at high doses

• Peripheral edema

Life Threatening Side Effects

• Hypertensive crisis (especially when MAOIs are used with certain tyramine-containing foods or prohibited drugs)

• Induction of mania in patients with bipolar disorder

• Rare seizures

• Rare hepatotoxicity

weight gain

problematic

sedation

common

What to do about PHENELZINE side effects

• Wait

• Wait

• Wait

• Lower the dose

• Take at night if daytime sedation

• Switch after appropriate washout to an SSRI or newer antidepressant

usual dosage range

• 45–75 mg/day

Dosage Forms

• Tablet 15 mg

long term use

• Consider periodic evaluation of hepatic function

• MAOIs may lose efficacy long-term

habit forming

• Dependence to MAOIs reported but rare

Renal Impairment

• Use with caution – drug may accumulate in plasma

• May require lower than usual adult dose

Hepatic Impairment

• Phenelzine should be used cautiously

Cardiac Impairment

• Contraindicated in patients with congestive heart failure or hypertension, unless cleared by the patient’s medical doctor

Elderly

• Initial dose 7.5 mg/day; increase every few days by 7.5–15 mg/day

• Elderly patients may have greater sensitivity to adverse effects, but many tolerate MAOIs

• Reduction in the risk of suicidality with antidepressants compared to placebo in adults age 65 and older

Children and Adolescents

• Not recommended for use under age 16

• Carefully weigh the risks and benefits of pharmacological treatment against the risks and benefits of nontreatment with antidepressants and make sure to document this in the patient’s chart

• Monitor patients face-to-face regularly, particularly during the first several weeks of treatment

• Use with caution, observing for activation of known or unknown bipolar disorder and/or suicidal ideation, and inform parents or guardians of this risk so they can help observe child or adolescent patients

Pregnancy

• Effective June 30, 2015, the FDA requires changes to the content and format of pregnancy and lactation information in prescription drug labels, including the elimination of the pregnancy letter categories; the Pregnancy and Lactation Labeling Rule (PLLR or final rule) applies only to prescription drugs and will be phased in gradually for drugs approved on or after June 30, 2001

• Controlled studies have not been conducted in pregnant women

• Not generally recommended for use during pregnancy, especially during first trimester

• Possible increased incidence of fetal malformations if phenelzine is taken during the first trimester

• Should evaluate patient for treatment with an antidepressant with a better risk/benefit ratio

Breast Feeding

• Some drug is found in mother’s breast milk

• If child becomes irritable or sedated, breast feeding or drug may need to be discontinued

• Immediate postpartum period is a high-risk time for depression, especially in women who have had prior depressive episodes, so drug may need to be reinstituted late in the third trimester or shortly after childbirth to prevent a recurrence during the postpartum period

• Should evaluate patient for treatment with an antidepressant with a better risk/benefit ratio