Isocarboxazid (Oral)


Often prescribed to patients who are unable to take selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs), Isocarboxazid is an older type of antidepressant. As a non-selective irreversible monoamine oxidase inhibitor, Isocarboxazid works by affecting the monoamine oxidase enzymes. Both types monoamine oxidase enzymes are involved in the metabolism of dopamine, serotonin and norepinephrine.

Although the exact causes of depression are still not fully understood, neurotransmitters, such as dopamine, norepinephrine and serotonin, are often heavily involved in the onset and the treatment of depressive illnesses. By binding to both MAO-A and MAO-B enzymes, Isocarboxazid can reduce the activity of both monoamine oxidase enzymes. In turn, there is an increase in the amount of norepinephrine, serotonin and dopamine in the patient's central nervous system. As a result, the symptoms of depression can be alleviated.

Whilst Isocarboxazid can be effective in treating depression, it is no longer a first-line treatment. Monoamine oxidase inhibitors interact with a number of other substances, including certain foods and drinks. Products which contain high levels of tyramine, such as cheese and/or alcohol, cannot normally be consumed whilst the patient is taking Isocarboxazid, or any other type of monoamine oxidase inhibitor. Due to this, patients have a much more restricted diet whilst taking this type of medication and the risk of toxicity or adverse effects is increased.

However, if patients are unable to take newer forms of antidepressants, such as SSRIs or SNRIs, then monoamine oxidase inhibitors, such as Isocarboxazid, may be appropriate. Similarly, if patients have previously tried taking SSRIs or SNRIs and have been unable to tolerate them or have not found them to be effective, Isocarboxazid may be prescribed as an alternative.

Providing patients follow their doctor's instructions when taking Isocarboxazid, it can be used to relieve the symptoms of depression. Whilst the drug is not commonly-prescribed, it does still have a place in the treatment of depression and is extremely effective for many patients.

Conditions Treated

Type Of Medicine

  • Monoamine oxidase (MAO) inhibitor
  • Antidepressant

Side Effects

Any type of medicine can cause patients to experience adverse effects but some medications cause more side effects than others. Monoamine oxidase inhibitors are associated with a considerable number of side effects and, when patients are taking Isocarboxazid, they may experience the following:

  • Decreased interest in sexual intercourse
  • Blurred vision
  • Drowsiness
  • Change in vision
  • Inability to have or keep an erection
  • Dry mouth
  • Loss in sexual drive, desire, performance or ability
  • Calm and relaxed
  • Sleepiness
  • Constipation
  • Sleeplessness
  • Inability to sleep
  • Trouble sleeping
  • Impaired vision
  • Unusual tiredness, weakness, dullness, drowsiness or feeling of sluggishness
  • Black tongue
  • Increased sensitivity of the skin to sunlight
  • Rash on the skin
  • Itching
  • Raised, wart-like dark red spots on the skin, especially on the face
  • Discoloration of the skin
  • Severe sunburn
  • Redness of the skin

The above side effects tend to occur more often when patients first start taking Isocarboxazid. As their body adjusts to the medicine, many of their side effects may be reduced or diminished completely. If the above side effects are mild and are not troublesome to the patient, they may not require medical attention. However, if they are severe or do not reduce over time, patients should obtain medical advice.

Patients should also inform their doctor immediately if they experience any of the following side effects whilst taking Isocarboxazid:

  • Itching, prickling, numbness, crawling, burning, tingling or "pins and needles feelings
  • Chills
  • Trouble sitting still
  • Cold sweats
  • Shaking or trembling of the feet or hands
  • Confusion
  • Sweating
  • Difficult urination
  • Lightheadedness, dizziness or faintness when getting up suddenly from a sitting or lying position
  • Racing, pounding irregular or fast pulse or heartrate
  • Fainting
  • Nervousness or fear
  • Shakiness in the arms, hands, feet or legs
  • Heavy feeling
  • Sudden jerky movements of the body
  • Increased need to urinate
  • Restlessness
  • Need to pass urine more often
  • Agitation
  • Loss of bladder control
  • Burning while urinating
  • Loss of consciousness
  • Change in consciousness
  • Swelling of the ankles, hands or face
  • Decrease in the frequency of urination
  • Stupor
  • Decrease in urine volume
  • Unsteady and shaky walk
  • Decreased urine output
  • Seizures
  • Depression
  • Hearing, feeling or seeing things that are not there
  • Difficulty in passing urine (dribbling)
  • Rapid weight gain
  • Dizziness
  • Unusual or false sense of well-being
  • Tingling or numbness of the feet, face or hands
  • Headache
  • Need to keep moving
  • Unusual weakness or tiredness
  • Hostility
  • Nausea
  • Irritability
  • Muscle twitching
  • Trembling, unsteadiness or other problems with muscle coordination or control

Patients should also obtain medical assistance if they experience any other side effects whilst taking Isocarboxazid.


When adult patients are prescribed Isocarboxazid, they are usually advised to take 10mg of the drug, twice per day. Once patients have become accustomed to this, their physician may increase their dose until the symptoms of depression have subsided. However, patients are not usually prescribed more than 60mg of Isocarboxazid per day.

Although this is an example of the standard treatment regime for Isocarboxazid, every patient will be assessed individually and will be given specific dosage instructions. Patients should, therefore, follow their doctor's advice and take Isocarboxazid as they have been instructed to do so.

If patients forget to take a dose of Isocarboxazid, they should take it as soon as they remember to do so. If their next dose is due soon, patients should avoid the missed dose completely and continue with their treatment schedule as normal. It is not appropriate for patients to take an extra or double dose of Isocarboxazid, even if an earlier dose has been missed.

When Isocarboxazid is prescribed, patients should ensure that they understand how and when to take the medication. If they are unsure, patients should seek advice from their physician or pharmacist.

Potential Drug Interactions

As monoamine oxidase inhibitors can interact with a significant number of substances, patients will need to show extra care when consuming any foods, drinking any beverages or taking any other medication.

For example, Isocarboxazid should not be prescribed in conjunction with the following medicines:

  • Amitriptyline
  • Dextromethorphan
  • Amoxapine
  • Dothiepin
  • Amphetamine
  • Dexmethylphenidate
  • Apraclonidine
  • Dobutamine
  • Atomoxetine
  • Diethylpropion
  • Benzphetamine
  • Dexfenfluramine
  • Brimonidine
  • Dextroamphetamine
  • Bupropion
  • Desvenlafaxine
  • Buspirone
  • Fenfluramine
  • Carbamazepine
  • Furazolidone
  • Carbidopa
  • Fluoxetine
  • Carbinoxamine
  • Femoxetine
  • Citalopram
  • Fluvoxamine
  • Clomipramine
  • Guanadrel
  • Clovoxamine
  • Guanethidine
  • Cyclobenzaprine
  • Imipramine
  • Cyproheptadine
  • Isocarboxazid
  • Desipramine
  • Hydroxytryptophan
  • Dopamine
  • Maprotiline
  • Doxepin
  • Lisdexamfetamine
  • Doxylamine
  • Lofepramine
  • Duloxetine
  • Levomilnacipran
  • Entacapone
  • Safinamide
  • Ephedrine
  • Tapentadol
  • Epinephrine
  • Sibutramine
  • Escitalopram
  • Sertraline
  • Isometheptene
  • Sumatriptan
  • Isoproterenol
  • Levodopa
  • Selegiline
  • Levomethadyl
  • Pargyline
  • Linezolid
  • Phendimetrazine
  • Mazindol
  • Phenmetrazine
  • Meperidine
  • Phentermine
  • Mephentermine
  • Paroxetine
  • Metaraminol
  • Phenelzine
  • Methadone
  • Phenylalanine
  • Methamphetamine
  • Procarbazine
  • Methotrimeprazine
  • Protriptyline
  • Methoxamine
  • Phenylpropanolamine
  • Methyldopa
  • Phenylephrine
  • Methylene Blue
  • Rizatriptan
  • Methylphenidate
  • Reserpine
  • Milnacipran
  • Tranylcypromine
  • Mirtazapine
  • Tetrabenazine
  • Nefazodone
  • Rasagiline
  • Nefopam
  • Trimipramine
  • Norepinephrine
  • Trazodone
  • Nortriptyline
  • Tryptophan
  • Opicapone
  • Vortioxetine
  • Opipramol
  • Vilazodone
  • Pseudoephedrine
  • Zolmitriptan
  • Venlafaxine

Similarly, taking Isocarboxazid alongside the following medicines is not usually recommended:

  • Almotriptan
  • Lorcaserin
  • Altretamine
  • Palonosetron
  • Atropine
  • Iobenguane I 123
  • Buprenorphine
  • Mate
  • Difenoxin
  • Hydromorphone
  • Diphenoxylate
  • Hydrocodone
  • Dolasetron
  • Guarana
  • Droperidol
  • Ma Huang
  • Ethchlorvynol
  • Reboxetine
  • Fentanyl
  • Oxycodone
  • Frovatriptan
  • Morphine Sulfate Liposome
  • Granisetron
  • Morphine
  • Kava
  • Tyrosine
  • Licorice
  • Tramadol
  • Metoclopramide
  • St John's Wort
  • Naratriptan
  • Tolcapone
  • Oxymetazoline
  • Ziprasidone

Furthermore, if patients take any of the following medicines, as well as Isocarboxazid, they are more likely to suffer from side effects:

  • Nateglinide
  • Glipizide
  • Metformin
  • Glyburide
  • Insulin
  • Repaglinide
  • Insulin Aspart, Recombinant
  • Acarbose
  • Insulin Bovine
  • Tolazamide
  • Insulin Degludec
  • Chlorpropamide
  • Insulin Detemir
  • Ginseng
  • Insulin Glargine, Recombinant
  • Glimepiride
  • Insulin Glulisine
  • Tolbutamide
  • Insulin Lispro, Recombinant

In addition to this, Isocarboxazid interacts with the following substances:

  • Tyramine containing foods
  • Caffeine

Due to this, caffeine and foods containing tyramine must be avoided when patients are taking Isocarboxazid.

The use of the following substances alongside Isocarboxazid is also not recommended:

  • Bitter orange
  • Avocado

As well as interacting with other prescription medicines, Isocarboxazid could interact with over-the-counter medicines, supplements or vitamins. Due to this, patients should tell their doctor if they are using any of these substances before they start taking Isocarboxazid. Patients should also obtain medical advice before they use any new medicines, vitamins or supplements once they have started taking Isocarboxazid.


If patients have a history of certain medical conditions or are currently experiencing other health problems, it may affect their use of Isocarboxazid. Patients should, therefore, discuss their existing health and medical history with their physician before they begin using Isocarboxazid. The following conditions may be particularly relevant if treatment with Isocarboxazid is being considered:

To date, the safety of Isocarboxazid in the pediatric population has not been specifically tested. Due to this, Isocarboxazid is only usually prescribed to adult patients and should not be used to treat children or infants.

Geriatric patients may be prescribed Isocarboxazid but they may be more likely to have age-related kidney or liver problems which could affect this use of this medication. If so, patients should be monitored regularly and their dose of Isocarboxazid may be altered in order to prevent toxicity occurring.

Before patients begin taking Isocarboxazid, their blood pressure should be checked by their physician. If patients experience any episodes of high or low blood pressure when taking Isocarboxazid, they should obtain medical advice.

Some patients may feel irritable or agitated when taking Isocarboxazid and they may exhibit abnormal behaviors. In some cases, patients may become more depressed or have suicidal tendencies and thoughts. If a patient, family member or caregiver notices these symptoms occurring, they must seek immediate medical help.

Isocarboxazid can interact with a number of substances and when an interaction occurs, patients may experience a hypertensive crisis. This is an episode of extremely high blood pressure and requires urgent medical treatment. In order to avoid a hypertensive crisis, patients must avoid particularly substances which are known to interact with Isocarboxazid.

For example, patients should not consume foods which have a high tyramine content and/or contain dopamine. These are usually foods which have been fermented or aged and may include:

  • Sour cream
  • Caviar
  • Cheese
  • Soy sauce
  • Canned figs
  • Liver
  • Fava beans
  • Sauerkraut
  • Yogurt
  • Yeasts
  • Smoked meats
  • Pickled meats
  • Bananas
  • Avocado
  • Raspberries
  • Very ripe fruit
  • Dried fruit

Patients should also avoid alcohol whilst taking Isocarboxazid. This includes beverages with a relatively low alcohol content, sherry, wine, liquors, beer and even non-alcoholic substitutes.

In addition to this, patients cannot consume or drink too much caffeine whilst taking Isocarboxazid. Patients should confirm with their doctor whether they need to cut caffeine out of their diet altogether or whether they are able to consume a small amount. Foods and drinks which contain caffeine and should be avoided include:

  • Tea
  • Coffee
  • Cola
  • Sports drinks
  • Soda
  • Chocolates
  • Energy drinks

If patients experience the following symptoms whilst taking Isocarboxazid, they may be having a hypertensive crisis and should seek emergency medical attention:

  • Dizziness
  • Sweating
  • Nausea or vomiting
  • Fast heartbeat
  • Chest pain
  • Sore or stiff neck
  • Headache

When taking Isocarboxazid, patients may feel drowsy, dizzy or less alert than they usually do. If affected in this way, patients should not operate machinery, drive or perform any other potentially dangerous tasks.

Isocarboxazid will add to the effects of other central nervous system suppressants and should not be taken in conjunction with them. These may include:

  • Alcohol
  • Cough, cold and flu remedies
  • Allergy medication
  • Barbiturates
  • Sinus medication
  • Muscle relaxants
  • Pain medication and narcotics
  • Sleeping medication
  • Epilepsy or seizure medication
  • Antihistamine
  • Tranquilizers
  • Sedatives
  • Anesthetics

As Isocarboxazid can interfere with the effect of anesthetics, patients should inform the relevant healthcare practitioners that they are taking this medication if they are due to undergo surgery or any medical procedures. Patients should also tell their dentist that they are taking Isocarboxazid before any dental work is carried out.

If patients require emergency medical treatment for an unrelated condition, they must notify the relevant healthcare practitioners that they are using Isocarboxazid and that they have taken this medicine within the last ten days. Some medications used in medical emergencies may interact with Isocarboxazid and cause serious side effects.

Patients may be advised to wear a medical identification bracelet and carry a medical identification card. This alerts people to the fact that they are taking Isocarboxazid and can be referred to in the event of an emergency.

If patients have any symptoms of a liver problem whilst taking Isocarboxazid, they will need to obtain urgent medical treatment. These symptoms may include:

  • Nausea or vomiting
  • Pale stools
  • Dark-colored urine
  • Pain in upper stomach
  • Loss of appetite
  • Yellowing of the skin or the whites of the eyes

If patients are advised to stop taking Isocarboxazid, the medication may remain in their system for some time. Due to this, patients should avoid foods and drinks which contain tyramine, dopamine and caffeine for at least two weeks after taking their last dose of Isocarboxazid. Similarly, patients will need to avoid medicines, supplements and vitamins which interact with Isocarboxazid during this time.

Isocarboxazid can affect the patient's blood sugar levels. Diabetic patients may be unable to take Isocarboxazid if it makes their blood sugar levels more difficult to control. If patients are due to undergo blood, urine or other medical tests, they should inform their physician that they are taking Isocarboxazid first as their test results may be affected.

Isocarboxazid has been classified as a category C drug in terms of the risk it poses to pregnant patients. If Isocarboxazid is taken by patients who are pregnant, it may cause harm to the unborn fetus. Due to this, Isocarboxazid is not usually prescribed to pregnant patients and should only be given to patients who are pregnant if there is no safer alternative available and if the benefits clearly outweigh the risks.

Patients may be advised to use an effective form of birth control whilst taking Isocarboxazid. If patients are already taking Isocarboxazid but are planning to become pregnant, they should contact their physician for advice before they attempt to conceive.

If patients become pregnant whilst taking Isocarboxazid, they should contact their physician for advice immediately.

Currently, it is not known whether Isocarboxazid can be transferred to an infant via breast milk or what level of risk this could pose to the child. As a result, patients are usually advised not to breastfeed whilst they are taking Isocarboxazid or for some time after they have taken their last dose of medicine. Patients should obtain medical advice before breastfeeding if they are taking Isocarboxazid or if they have taken it in the past.

Before patients begin using Isocarboxazid, they should tell their doctor if they have any allergies or have ever developed an allergic reaction to any substances. This includes allergies to foods, medicines, animals, dyes and/or preservatives. In rare cases, patients may develop an allergic reaction when taking Isocarboxazid. If so, they will require emergency medical treatment. The symptoms of an allergy may include:

  • Wheezing
  • Difficulty swallowing
  • Difficulty breathing
  • Hives
  • Shortness of breath
  • Itching
  • Hoarseness
  • Swelling of the lips, tongue, mouth, throat, face or lips
  • Rash on the skin


As patients are usually advised to take Isocarboxazid twice daily, they will need to keep a supply of medication at home. However, patients must use a secure location to keep their medicine safe and to prevent anyone else from accessing it. It is particularly important that children and/or pets cannot gain access to Isocarboxazid or any other medicines which may be in the home. Patients may consider using a locked medicine cabinet or secure medicine box when storing Isocarboxazid at home.

When keeping Isocarboxazid in the home, patients should follow the medication guidelines. Usually, Isocarboxazid can be kept at room temperature but should be stored in a closed container. Similarly, Isocarboxazid should be kept away from heat, moisture and direct light.

If patients are advised to stop taking Isocarboxazid or if the medicine reaches its expiration date, patients should no longer keep it at home. Instead, they should dispose of it carefully. Medicines should not be thrown out with regular household waste as they could cause harm to other people. Instead, patients should contact their pharmacist or physician's office and make use of a specialist medicine disposal service.


Due to its effect on monoamine oxidase enzymes, Isocarboxazid can be extremely effective in treating depression and reducing the patient's symptoms. However, the drug does interact with a number of substances and treatment with Isocarboxazid may, therefore, be restrictive for the patient.

If patients are prescribed Isocarboxazid, it is vital that they undergo regular monitoring and that they avoid consuming substances which are known to interact with monoamine oxidase inhibitors. As serious health problems can occur as a result of toxicity, Isocarboxazid should only be prescribed if patients are able to adhere to the specific medication guidelines which accompany Isocarboxazid.

Although patients with depression are more commonly treated with SSRIs and SNRIs, monoamine oxidase inhibitors may be a suitable form of treatment for patients who have not benefited from SSRIs or SNRIs or patients who are unable to take these types of medications. Due to this, Isocarboxazid remains a vital drug in the treatment of depression and is still beneficial for a considerable number of patients.