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Isocarboxazid, Oral

What are other names for this medicine?

Type of medicine: MAO inhibitor antidepressant

Generic and brand names: isocarboxazid, oral; Marplan

What is this medicine used for?

This medicine is an MAO inhibitor taken by mouth to treat certain types of depression.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have:

  • an allergy to any medicine
  • a seizure disorder (epilepsy)
  • diabetes
  • heart disease
  • high blood pressure
  • kidney or liver disease
  • Parkinson's disease
  • thyroid disease.

Also tell your provider if you have ever had:

  • a tumor of the adrenal gland
  • a stroke
  • problems with hyperactivity
  • severe or frequent headaches
  • schizophrenia or other mental disorders.

Tell your provider about all other medicines you are taking, especially painkillers or antidepressants. You may need to wait at least 14 days between using an MAO inhibitor and any other medicine.

Females of childbearing age: Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known whether this medicine will harm an unborn baby. Do not breast-feed while taking this medicine without your healthcare provider's approval.

How do I take it?

Take this medicine exactly as your healthcare provider prescribes. Do not take more or less of it or take it longer than prescribed. Do not stop taking this medicine without your provider's approval. Take each dose with a full glass of water.

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What should I watch out for?

Children and teens who take antidepressants are more likely to think about harming or killing themselves or try to do so than children who do not take antidepressants. Talk with your provider about this.

Important note: Stop taking this medicine and get medical care right away if you have heavy sweating, severe chest pain, severe headache, faster or slower heartbeat, large pupils, stiff neck, nausea, vomiting, or any other serious effects.

This medicine may make you drowsy. Do not drive or operate machinery unless you are fully alert.

You may feel dizzy or faint when you get up quickly after sitting or lying down. Getting up slowly may help. Also, drinking alcohol may make it worse. Do not drink alcohol unless your healthcare provider approves.

Do not take any other medicines without your healthcare provider's approval. If you need surgery, emergency care, lab tests, or dental work, tell the healthcare provider or dentist you are taking this medicine.

Certain foods, drinks, and medicines can cause dangerously high blood pressure if you consume them while taking this medicine. Talk with your healthcare provider about which foods, drinks, and drugs you may take with this medicine.

You need to check your blood pressure regularly while taking this medicine. You may need to have blood tests to see how the medicine affects you. Keep all appointments for these tests.

Diabetics: This medicine may affect your blood sugar level and change the amount of insulin or other diabetes medicines you may need. Talk to your healthcare provider about this.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat).

Serious (report these to your healthcare provider right away): Dark urine, rash, diarrhea, swelling, yellowish eyes or skin, heavy sweating, severe chest pain, severe headache, faster or slower heartbeat, large pupils, stiff neck, nausea, vomiting.

Other: Dry mouth, trouble urinating, trembling, mild headache, blurred vision, weakness, drowsiness, dizziness, constipation, trouble sleeping, change in sexual ability or desire.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Also, using these medicines together might cause harmful side effects. Talk to your healthcare provider if you are taking any of these medicines:

  • ACE inhibitors such as enalapril (Vasotec), lisinopril (Prinivil, Zestril), fosinopril (Monopril), captopril (Capoten), quinapril (Accupril), ramipril (Altace), and benazepril (Lotensin)
  • amphetamines and certain appetite suppressants such as methylphenidate (Ritalin, Concerta, Methylin), dextroamphetamine (Dexedrine), methamphetamine (Desoxyn), and sibutramine (Meridia)
  • antianxiety medicines such as clonazepam (Klonopin), alprazolam (Xanax), clorazepate (Tranxene), diazepam (Valium), lorazepam (Ativan), oxazepam, triazolam (Halcion), temazepam (Restoril), and flurazepam (Dalmane)
  • antidepressants such as imipramine (Tofranil), amitriptyline, amoxapine, clomipramine (Anafranil), desipramine (Norpramin), doxepin (Sinequan), maprotiline (Ludiomil), nefazodone, perphenazine and amitriptyline, protriptyline (Vivactil), trazodone (Desyrel), trimipramine (Surmontil), citalopram (Celexa), fluoxetine (Prozac), fluvoxamine, mirtazapine (Remeron), paroxetine (Paxil), sertraline (Zoloft), venlafaxine (Effexor), duloxetine (Cymbalta), and bupropion (Wellbutrin, Zyban)
  • antihistamines such as such as diphenhydramine (Benadryl) and chlorpheniramine (Chlor-Trimeton, Alavert)
  • beta blockers such as atenolol (Tenormin), pindolol, metoprolol (Lopressor, Toprol), bisoprolol (Zebeta), and propranolol (Inderal)
  • bronchodilators such as albuterol (Proventil), arformoterol (Brovana), and metaproterenol (Alupent)
  • buspirone (BuSpar)
  • calcium channel blockers such as nifedipine (Procardia, Adalat), felodipine (Plendil), amlodipine (Norvasc), diltiazem (Cardizem, Dilacor), and verapamil (Calan, Isoptin)
  • carbamazepine (Tegretol)
  • cyclobenzaprine (Flexeril)
  • cough, cold, or allergy medicines such as cyproheptadine (Periactin), dextromethorphan (Robitussin DM), ephedrine, phenylephrine (Neo-Synephrine), and pseudoephedrine (Sudafed)
  • diuretics such as hydrochlorothiazide (Microzide) and furosemide (Lasix)
  • insulin and oral medicines to treat diabetes such as glyburide (DiaBeta, Micronase) and glipizide (Glucotrol)
  • linezolid (Zyvox)
  • medicines to treat Parkinson's disease such as levodopa/carbidopa (Sinemet), bromocriptine (Parlodel), and entacapone (Comtan)
  • methyldopa (Aldomet)
  • migraine medicines such as rizatriptan (Maxalt), sumatriptan (Imitrex), and zolmitriptan (Zomig)
  • narcotic analgesics (painkillers) such as codeine, hydrocodone (Vicodin, Lortab), oxycodone (Percocet, Tylox, OxyContin), pentazocine (Talwin), fentanyl (Actiq, Duragesic patches), hydromorphone (Dilaudid), methadone (Dolophine, meperidine (Demerol), morphine (MS Contin), and tramadol (Ultram)
  • phenothiazines such as chlorpromazine (Thorazine), fluphenazine (Permitil, Prolixin), perphenazine, prochlorperazine (Compazine), trifluoperazine (Stelazine), and thioridazine
  • procarbazine (Matulane)
  • reserpine
  • sedatives such as phenobarbital and butabarbital (Butisol)

When taken with certain foods or drinks, this medicine can cause an increase in blood pressure. To avoid this, do not eat large amounts of foods or drink beverages that have a high tyramine content. This includes foods that are aged, fermented, pickled, or smoked, such as aged cheeses; yogurt, dried fruits, smoked fish, meat, or poultry; sauerkraut; soy sauce; red wine; or tap beer. Avoid caffeine and chocolate. Discuss this with your healthcare provider.

Do not drink alcohol while taking this medicine.

Keep a list of all your medicines (prescription, nonprescription, supplements, natural remedies, and vitamins) with you. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.


This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.

Developed by McKesson Corporation
Published by McKesson Corporation.
Last modified: 2007-04-16
Last reviewed: 2006-10-30
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright © 2007 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.
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