ISOCARBOXAZID
THERAPEUTICS
Class
- Neuroscience-based Nomenclature: serotonin, norepinephrine, dopamine enzyme inhibitor (SN-EI)
- Monoamine oxidase inhibitor (MAOI)
ISOCARBOXAZID commonly prescribed for
(Bold for FDA approved)
How ISOCARBOXAZID works
• Irreversibly blocks monoamine oxidase (MAO) from breaking down norepinephrine, serotonin, and dopamine
• This boosts noradrenergic, serotonergic, and dopaminergic neurotransmission
How long until ISOCARBOXAZID 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
SIDE EFFECTS
Notable Side Effects
• Dizziness, sedation, headache, sleep disturbances, fatigue, tremor
• Change in appetite, weight gain
• Sexual dysfunction
• Orthostatic hypotension (dose-related); syncope may develop at high doses
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

common
sedation

common
What to do about ISOCARBOXAZID side effects
• Wait
• Wait
• Wait
• Lower the dose
• Take at night if daytime sedation
• Switch after appropriate washout to an SSRI or newer antidepressant
DOSING AND USE
usual dosage range
• 40–60 mg/day
Dosage Forms
• Tablet 10 mg
long term use
• Consider periodic evaluation of hepatic function
• MAOIs may lose some efficacy long-term
habit forming
• Dependence to MAOIs reported but rare
SPECIAL POPULATIONS
Renal Impairment
• Use with caution – drug may accumulate in plasma
• May require lower than usual adult dose
Hepatic Impairment
• Use cautiously in hepatic impairment
Cardiac Impairment
• Contraindicated in patients with congestive heart failure or hypertension, unless cleared by the patient’s medical doctor
Elderly
• Initial dose lower than usual adult dose
• 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 in children 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
• Distribute the brochures provided by the FDA and the drug companies
• Whenever possible, warn patients and their caregivers about the possibility of activating side effects, and advise them to report such symptoms immediately
• 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
• 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
• 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
Based on data Published online by Cambridge University Press
Compiled by Dr. Jash Ajmera