Isocarboxazid
Isocarboxazid is a monoamine oxidase inhibitor (MAOI) used to treat major depressive disorder. It works by blocking the enzyme monoamine oxidase, which normally breaks down neurotransmitters like serotonin and norepinephrine, thereby increasing their levels in the brain. This medication is typically reserved for patients who have not responded to other antidepressant treatments.
Isocarboxazid is an MAOI antidepressant used when other treatments fail, requiring strict dietary and medication restrictions to prevent dangerous interactions.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- N06AF01
- RxNorm
- 6011
- Generic
- Isocarboxazid
- Class
- atc-n06
- Brands
- Marplan
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Primarily prescribed for major depressive disorder (MDD) that has not responded to other antidepressants. May be used for other mood disorders as determined by a healthcare provider.
Isocarboxazid inhibits monoamine oxidase enzymes (MAO-A and MAO-B), preventing the breakdown of neurotransmitters such as serotonin, norepinephrine, and dopamine. This increases the concentration of these chemicals in the brain, helping to improve mood and alleviate depressive symptoms.
Requires strict dietary restrictions—avoiding tyramine-rich foods (aged cheeses, cured meats, fermented foods) to prevent hypertensive crisis. Multiple drug interactions with other antidepressants, sympathomimetics, and certain pain medications. Requires a washout period when switching to or from other MAOIs or SSRIs. Patients should carry identification indicating MAOI use. Blood pressure monitoring may be required during treatment.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy