Marplan

(Isocarboxazid)

The generic name for Marplan is isocarboxazid.

Marplan works as a monoamine oxidase inhibitor (MAOI) antidepressant by blocking the enzyme monoamine oxidase, which normally breaks down neurotransmitters like serotonin, norepinephrine, and dopamine in the brain. By inhibiting this enzyme, Marplan increases the levels of these mood-regulating chemicals, helping improve mood and relieve symptoms of depression. Because it affects multiple neurotransmitters and enzyme pathways, it requires careful dietary and medication restrictions to avoid serious interactions.

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide before using Marplan. However, the following is a synopsis of the general guidelines for the use of Marplan:

• Marplan is taken by mouth as a tablet.
• It is usually taken two to four times per day, depending on the prescribed dose.
• Take Marplan at the same time each day to keep drug levels consistent.
• Tablets may be taken with or without food.
• Do not stop taking Marplan suddenly unless directed by your healthcare provider.
• Avoid foods and beverages high in tyramine while taking Marplan and for at least 2 weeks after stopping treatment.
• Avoid alcohol unless your healthcare provider says it is safe.
• If a dose is missed, take it as soon as remembered unless it is close to the next dose.

Some mild or common side effects of Marplan seen in clinical trials include:

• Dizziness or lightheadedness.
• Drowsiness or fatigue.
• Dry mouth.
• Constipation.
• Headache.
• Trouble sleeping.
• Nausea.

Some individuals may experience serious side effects while using Marplan. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Severe headache, chest pain, or tightness.
• Very high blood pressure.
• Fast or irregular heartbeat.
• Confusion or agitation.
• Signs of serotonin syndrome include fever, sweating, tremor, or muscle stiffness.
• Fainting or severe orthostatic hypotension.
• Suicidal thoughts or sudden changes in mood or behavior.
• Yellowing of the skin or eyes indicates liver problems.

These are not all of the possible side effects of Marplan. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Marplan, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including:

• High blood pressure or a history of hypertension.
• Heart disease or chest pain.
• Liver disease or impaired liver function.
• Bipolar disorder, schizophrenia, or other psychiatric conditions.
• A history of suicidal thoughts or behavior.
• Pheochromocytoma.
• Seizure disorders.
• A history of substance use disorder.
• Are scheduled for surgery or dental procedures.
• Are taking supplements such as tryptophan or tyrosine.

Boxed Warning

Marplan has an FDA boxed warning.

Antidepressants, including Marplan, increase the risk of suicidal thoughts and behaviors in children, adolescents, and young adults.

Patients should be closely monitored for worsening depression, suicidal thoughts, or unusual changes in behavior, especially during the first few months of treatment or when the dose is changed.

Marplan is not approved for use in pediatric patients.

Marplan should not be used in patients with pheochromocytoma, severe heart disease, liver disease, or a known hypersensitivity to isocarboxazid. It must not be used with other monoamine oxidase inhibitors or within 14 days of stopping or starting certain antidepressants, stimulants, or other interacting medications. It should not be used with dextromethorphan, meperidine, or certain sympathomimetic drugs.

Some improvement in depressive symptoms may be noticed within 1 to 2 weeks, but full antidepressant effects can take 4 to 6 weeks or longer. Continue taking Marplan exactly as prescribed, even if you do not feel better right away.

When Marplan is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

• SSRIs (serotonin reuptake inhibitors) and other antidepressants such as fluoxetine, sertraline, paroxetine, citalopram, amitriptyline, and nortriptyline, due to the risk of serotonin syndrome.
• Other MAO inhibitors, such as phenelzine, tranylcypromine, or selegiline, are contraindicated due to severe interactions.
• Dextromethorphan, due to the risk of serotonin syndrome.
• Meperidine, due to the risk of life-threatening reactions.
• Stimulants, including amphetamines, epinephrine, and methylphenidate, due to dangerous increases in blood pressure.
• Bupropion, due to seizure and blood pressure risk.
• Buspirone, due to increased blood pressure risk.
• Supplements such as tryptophan can cause serotonin syndrome.
• Tyramine-rich foods, including aged cheeses, soy sauce, fermented meats, yeast extracts, avocados, and certain alcoholic beverages (red wine), due to hypertensive crisis.
• Carbamazepine increases the toxicity of isocarboxazid.
• Certain muscle relaxants, such as carisoprodol and cyclobenzaprine.
• Some high blood pressure medications, including guanethidine, methyldopa, atenolol, and clonidine.

Marplan tablets are available as 10 mg tablets.

Dosage summary based on prescribing information:

Initial dosing typically starts at 10 mg two times per day.

The dose may be gradually increased by the healthcare provider.

Usual effective dose ranges from 40 mg to 60 mg per day, given in divided doses.

Maximum daily doses should not be exceeded.

Dose adjustments may be required based on response and side effects.

Marplan is approved for use in adults only.

It should be stored at room temperature, away from the reach of children or pets.

Marplan is manufactured by Validus Pharmaceuticals.

Yes, isocarboxazid is available as a generic medication.

Do not stop taking Marplan suddenly without medical guidance. Your healthcare provider will gradually reduce your dose to avoid withdrawal symptoms and reduce the risk of adverse effects. Dietary and drug restrictions must continue for at least 14 days after stopping Marplan.

Marplan should only be used during pregnancy if the potential benefit clearly outweighs the potential risk to the unborn baby. If pregnancy occurs while taking Marplan, contact your healthcare provider immediately.

Breastfeeding is not recommended while taking Marplan, as it is not known whether isocarboxazid passes into breast milk or what effects it could have on your infant.