Generic Name: Mirtazapine Brand Name(s): Generics only. No brands available.


What is mirtazapine used for?

Mirtazapine is used to treat depression. It improves mood and feelings of well-being. Mirtazapine is an antidepressant that works by restoring the balance of natural chemicals (neurotransmitters) in the brain.

How should I take mirtazapine?

Take this medication by mouth, with or without food, usually once daily at bedtime or as directed by your doctor. The dosage is based on your medical condition and response to therapy, but should not exceed 45 milligrams per day.

Use this medication regularly in order to get the most benefit from it. Remember to use it at the same time each day. It may take between 1-4 weeks to notice improvement in your symptoms. Therefore, do not increase your dose or take it more often than prescribed.

It is important to continue taking this medication even if you feel well. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when the drug is abruptly stopped. Your dose may need to be gradually decreased.

Inform your doctor if your condition persists or worsens.

How do I store mirtazapine?

Mirtazapine is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store mirtazapine in the bathroom or the freezer. There may be different brands of mirtazapine that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush mirtazapine down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using mirtazapine?

Before using this drug, tell your doctor if:

  • You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • You have allergy with any of active or inactive ingredients of mirtazapine or other medications.
  • You have any other illnesses, disorders, or medical conditions.

Tell your doctor if you are taking a monoamine oxidase (MAO) inhibitor such as isocarboxazid (Marplan), linezolid (Zyvox), methylene blue, phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate) or if you have stopped taking an MAO inhibitor within the past 14 days. Your doctor will probably tell you not to take mirtazapine. If you stop taking mirtazapine, you should wait at least 14 days before you start to take an MAO inhibitor.

Tell your doctor what herbal products you are taking, especially St. John’s wort and tryptophan.

Tell your doctor if you have or have ever had a heart attack, low blood pressure, heart, kidney, or liver disease, or high cholesterol.

If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking mirtazapine.

You should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.

Remember that alcohol can add to the drowsiness caused by this medication.

If you have phenylketonuria (PKU, an inherited condition in which a special diet must be followed to prevent mental retardation), you should know that the orally disintegrating tablets contain aspartame that forms phenylalanine.

You should know that mirtazapine may cause angle-closure glaucoma (a condition where the fluid is suddenly blocked and unable to flow out of the eye causing a quick, severe increase in eye pressure which may lead to a loss of vision). Talk to your doctor about having an eye examination before you start taking this medication. If you have nausea, eye pain, changes in vision, such as seeing colored rings around lights, and swelling or redness in or around the eye, call your doctor or get emergency medical treatment right away.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using mirtazapine during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking mirtazapine. Mirtazapine is pregnancy risk category C, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from mirtazapine?

Get emergency medical help if you have any of these signs of an allergic reaction: skin rash or hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have a serious side effect such as:

  • Agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination
  • Very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors
  • Feeling like you might pass out
  • Fever, chills, body aches, flu symptom
  • White patches or sores inside your mouth or on your lips
  • Headache, trouble concentrating, memory problems, weakness, or feeling unsteady

Less serious side effects include:

  • Drowsiness, dizziness
  • Increased appetite
  • Weight gain

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with mirtazapine?

Mirtazapine may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products that may interact with this drug are:

  • Cimetidine (Tagamet)
  • Diazepam (Valium)
  • Ketoconazole
  • John’s wort
  • Tramadol
  • Tryptophan (sometimes called L-tryptophan)
  • Medicine to treat mood disorders, thought disorders, or mental illness – such as lithium, other antidepressants, or antipsychotics
  • Migraine headache medicine – sumatriptan, zolmitriptan, and others
  • Seizure medicine – carbamazepine, phenytoin

Does food or alcohol interact with mirtazapine?

Mirtazapine may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with mirtazapine?

Mirtazapine may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

Health conditions that may interact with this drug are:

  • Angina (severe chest pain)
  • Blood vessel disease or circulation problems
  • Dehydration
  • Heart attack
  • Heart disease
  • Hypotension (low blood pressure)
  • Hypovolemia (low blood volume)
  • Stroke
  • Bipolar disorder (mood disorder with mania and depression)
  • Glaucoma (angle-closure type)
  • Hypercholesterolemia (high cholesterol in the blood)
  • Hyponatremia (low sodium in the blood)
  • Mania or hypomania
  • Seizures
  • Kidney disease
  • Liver disease
  • Phenylketonuria (a metabolic disorder)


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using mirtazapine.

What is the dose of mirtazapine for an adult?

Usual Adult Dose for Depression

Initial dose: 15 mg orally once a day at bedtime.

Maintenance dose: 15 to 45 mg per day.

What is the dose of mirtazapine for a child?

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is mirtazapine available?

Mirtazapine is available in the following dosage forms and strengths:

  • Tablet, Oral: 7.5 mg, 15 mg, 30 mg, 45 mg.
  • Tablet, Oral disintegrating: 15 mg, 30 mg, 45 mg.

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of mirtazapine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

msBahasa Malaysia

Review Date: July 18, 2017 | Last Modified: July 25, 2017

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