Oct 6th 2023
Isocarboxazid is an antidepressant drug used to treat people who do not experience adequate symptom relief with other types of antidepressant medication. While it can be effective in the treatment of depression, isocarboxazid is not the first choice for treating this mental health condition, because of safety concerns, side effects, and dietary restrictions that come along with it  .
In the United States, isocarboxazid is most commonly marketed under the brand name Marplan .
Isocarboxazid is an antidepressant drug, but it can be prescribed for multiple psychiatric conditions. It is used to treat not only major depressive disorder, but also dysthymia (persistent depression), panic disorder, and phobias . Given the safety concerns associated with this medication, it is not a first line of treatment for any mental health disorder. Rather, it is prescribed in patients who do not respond to other medications .
Isocarboxazid belongs to a class of drugs called monoamine oxidase inhibitors (MAOI). As the name suggests, this drug class works by blocking activity of the monoamine oxidase enzyme, which is responsible for breaking down numerous neurotransmitters, including dopamine, tyramine, serotonin, and norepinephrine .
By blocking the activity of the monoamine oxidase enzyme, isocarboxazid stops the breakdown of these neurotransmitters, and increases their availability in the nervous system. This allows the neurotransmitters to act upon the cells that are affected by depression and related psychiatric disorders .
Isocarboxazid comes in tablet form and is taken by mouth, usually between two and four times per day. The medication is available as a 10 mg tablet. It’s important to take this medication exactly as prescribed. Your doctor and pharmacist will be able to tell you how often to take isocarboxazid  .
Isocarboxazid is rapidly metabolized by the liver. The medication has a half-life of 1.5 to 4 hours, which is the amount of time it takes half of the original dose of the drug to leave the system. Most of a drug is eliminated from the body after 4 to 5 half-lives, meaning that it takes 6 to 20 hours for isocarboxazid to leave the system  .
Isocarboxazid, like any medication, comes with side effects. If your doctor has prescribed this medication, they have determined that the benefits of the medication outweigh the potential risk of adverse effects. However, if side effects are severe and interfere with daily life, it’s important to discuss them with your doctor.
Common side effects of isocarboxazid include :
The side effects above are often considered mild, and they may improve with time. More severe side effects associated with isocarboxazid include:
If you experience severe side effects, contact your doctor immediately, or present to an emergency room for immediate medical care.
In addition to being mindful of potential side effects, it’s essential to be aware of the following safety precautions that apply when taking isocarboxazid :
There are various substances and medications that can cause potentially dangerous interactions when taken in combination with isocarboxazid, which is why it’s essential to tell your doctor about all substances and medications you’re using. The following substances are known to cause potential interactions with isocarboxazid, but there are additional medications that could also be problematic   :
The list above is not exhaustive and does not include every specific medication that can interact with isocarboxazid, so you must consult with a doctor about the potential interaction between isocarboxazid and any medications you’re taking.
Isocarboxazid should be stored at room temperature. It should not be kept in a bathroom, since it should be away from excess heat and moisture. Keep the medication in its original container, out of reach of children. Keeping isocarboxazid in a pill container or in other locations where children can reach it could result in unintentional poisoning .
Isocarboxazid can result in overdose. Symptoms of overdose include elevated heart rate, dizziness, fainting, blurred vision, seizures, slowed breathing or reflexes, fever, sweating, nausea, and coma .
If you or someone you know shows signs of isocarboxazid overdose, contact poison control immediately. If a person has collapsed, is non-responsive, has a seizure, or has trouble breathing, call 911 or take them to the emergency room immediately .
Our Medical Affairs Team is a dedicated group of medical professionals with diverse and extensive clinical experience who actively contribute to the development of our content, products, and services. They meticulously evaluate and review all medical content before publication to ensure it is medically accurate and aligned with current discussions and research developments in mental health. For more information, visit our Editorial Policy.
MentalHealth.com is a patient-first health technology company driven by its mission to make optimal mental health attainable for everyone. With a focus on expanding care access, empowering patient choice, and enhancing care quality, the company delivers innovative solutions that support individuals throughout their mental health journey.