Drug information of isocarboxazid


Drug group:

Isocarboxazid is an MAO inhibitor that is effective in the treatment of major depression, dysthymic disorder, and atypical depression. It also is useful in the treatment of panic disorder and the phobic disorders

Mechanism of effect

Isocarboxazid works by irreversibly blocking the action of a chemical substance known as monoamine oxidase (MAO) in the nervous system. MAO subtypes A and B are involved in the metabolism of serotonin and catecholamine neurotransmitters such as epinephrine, norepinephrine, and dopamine. Isocarboxazid, as a nonselective MAO inhibitor, binds irreversibly to monoamine oxidase–A (MAO-A) and monoamine oxidase–B (MAO-B)


Isocarboxazid is a monoamine oxidase inhibitor, effective in small doses. Its antidepressant action is thought to be related to its effect on physiological amines such as serotonin and noradrenaline, and this effect is cumulative and persistent.

Drug indications



10 mg PO q6-12hr, increase by 10 mg/day q2-4d to 40 mg/day PO divided q6-12hr by end of first week

After first week, may increase by up to 20 mg/week to maximum 60 mg/day; decrease dose to maintenance dose once maximum effect achieved

Drug contraindications

Heart disease

Isocarboxazid is contra-indicated in patients with any impairment of hepatic function, cerebrovascular disorders or severe cardiovascular disease, and in those with actual or suspected phaeochromocytoma.
Selective serotonin reuptake inhibitors (SSRIs): Cases of serious and sometimes fatal reactions (serotonin syndrome) have been reported in patients receiving monoamine oxidase inhibitors (MAOIs) in combination with SSRIs, and in patients who have recently discontinued an SSRI and have been started on a MAOI. Treatment with SSRIs should only be started 2 weeks after discontinuation of Isocarboxazid.
Conversely, treatment with Isocarboxazid should not be started until at least a week after stopping a SSRI or related anti-depressant (at least 5 weeks for fluoxetine).

Patients being treated with a monoamine oxidase inhibitor should not receive indirectly-acting sympathomimetic agents such as amphetamines, metaraminol, fenfluramine or similar anorectic agents, ephedrine or phenylpropanolamine (contained in many proprietary 'cold-cure' medications), dopamine or levodopa. Patients should also be warned to avoid foodstuffs and beverages with a high tyramine content:
mature cheeses (including processed cheeses), hydrolysed yeast or meat extracts, alcoholic beverages, particularly heavy red wines such as Chianti, non-alcoholic beers, lagers and wines, and other foods which are not fresh and are fermented, pickled, 'hung', 'matured' or otherwise subject to protein degradation before consumption.
Broad bean pods (which contain levodopa) and banana skins may also present a hazard. In extreme cases interactions may result in severe hypertensive episodes. Isocarboxazid should therefore be discontinued immediately upon the occurrence of palpitations or frequent headaches.


Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.

Weakness on 1 side of the body, trouble speaking or thinking, change in balance, drooping on one side of the face, or blurred eyesight.

Chest pain or pressure.

Fast or slow heartbeat.

Very upset stomach or throwing up.


A heartbeat that does not feel normal.

Neck stiffness.

Sweating a lot.

Larger pupils.

If bright lights bother your eyes.

Very bad dizziness or passing out.


Points of recommendation

Consult your doctor or pharmacist if you have: pheochromocytoma, cerebrovascular disease (e.g., stroke), heart problems (e.g., congestive heart failure, heart attack), high blood pressure, history of severe/frequent headaches, liver problems.personal/family history of mental/mood disorders (e.g., schizophrenia, bipolar disorder), family history of high blood pressure, heart disease (e.g., coronary artery disease, history of chest pain), kidney disease, certain nervous system diseases (Parkinson's syndrome, seizures), overactive thyroid (hyperthyroidism), personal/family history of glaucoma (angle-closure type).

This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.

Pregnancy level



Ask a Pharmacist

User's questions
    No comments yet.