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Brand Name(s) : Zispin soltab
Side Effects


Mirtazapine should be used with caution in:

It should not be used in:

  • Hypersensitivity to mirtazapine
  • While on MAO inhibitors (antidepressants) or within two weeks after stopping these medications
  • Rare hereditary problems of galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption

Also see list of precautions and interactions


Keep the tablets in the container in a dry place, away from the light, below 25 °C.


Mirtazapine is used to treat major episodes of depression.

It is an antidepressant. It belongs in the class of antidepressants known as noradrenergic and specific serotonergic antidepressants (NaSSA).

It is used to increase the levels of certain chemicals in the brain that are found at low levels if you have depression.

In general this drug is used in the treatment of major depression. This is a mood disorder, a condition in which you may feel low, have low self-esteem, and have lost the ability to enjoy activities you usually enjoy.

Benefits of being on this drug can include improving your mood.

Listed below are the typical uses of mirtazapine.

  • Major depression

Mirtazapine is not licensed to treat any other conditions.


How often do I take it?

  • Take this medication by mouth usually once daily with a drink immediately before bedtime. The daily dose can be divided into two doses, one taken in the morning and one taken at bedtime.
  • Use this medication for the duration of prescription in order to get the most benefit from it.
  • Remember to use it at the same time each day - unless specifically told not to by your doctor.
  • It may take up to 2-4 weeks before the full benefit of this drug takes effect.
  • Certain medical conditions may require different dosage instructions as directed by your doctor.

What dose?

  • Dosage is based on your age, gender, medical condition, response to therapy, and use of certain interacting medicines.

Do I need to avoid anything?

  • You should not take other antidepressants known as monoamine oxidase inhibitors (MAOIs) while on mirtazapine or in the 2 weeks before starting mirtazapine. Other antidepressants (e.g. nefazodone) or medicines containing the product serotonin (e.g. fluoxetine, paroxetine) should be used with caution. You should not take alcohol while on mirtazapine as it may cause drowsiness. Mirtazapine may reduce concentration, alertness, and judgement, especially in the beginning of treatment. When you first start taking mirtazapine, make sure your abilities are not affected before you drive or operate machinery. Consult your doctor or pharmacist for more details.

When can I stop?

  • It is important to continue taking this medication even if you feel well, unless your doctor tells you to stop. You should not suddenly stop taking mirtazapine. If you do, you may feel, sick, unwell, and have headaches, and your symptoms may return.


  • Increased appetite and weight gain
  • Drowsiness (which may impair alertness), particularly during the first few weeks of therapy
  • Dizziness
  • Headache
  • Generalised or local oedema (fluid retention, e.g. swollen ankles) and accompanying weight gain
  • Fatigue

If any of these persist or you consider them severe then inform doctor or pharmacist.

Tell your doctor immediately if you develop any of the following symptoms:

  • fits (seizures or convulsions)
  • an allergic reaction (such as swelling of the lips, face and tongue, difficulty breathing, feeling faint)
  • a decreased resistance to infection

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine (which includes vaccines, herbals and over the counter medicines) that you are taking. It is run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory agency (MHRA). Please report any suspected side effect on the Yellow Card Scheme website.


Before taking mirtazapine, tell your doctor or pharmacist if you are allergic to it; or to other NaSSA antidepressants; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: Hypersensitivity (allergy) to mirtazapine, you are pregnant or breastfeeding, are on MAO inhibitors (antidepressants) or have stopped taking them less than two weeks ago, or if you have one of the following rare hereditary problems: galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption.

Before using this medication, tell your doctor or pharmacist your medical history, especially any of the following: epilepsy, liver disease, kidney disease, heart disease, low blood pressure, enlarged prostate or difficulty urinating, which might indicate enlarged prostate, glaucoma (raised eye pressure), diabetes mellitus, schizophrenia or jaundice

Before having surgery, tell your doctor or dentist that you are taking this medication.

Does alcohol intake affect this drug?

  • Yes. Taking alcohol while on mirtazapine may make you more drowsy.

The elderly: mirtazapine should be used with caution in the elderly. Elderly patients are often more sensitive especially to the undesirable effects of antidepressants. In clinical studies of mirtazapine, the levels of side effects were not higher in elderly patients, but experience is still limited.

Pregnancy and breastfeeding - please ensure you read the detailed information below


Experience with using mirtazapine in pregnancy is limited, hence it should only be used if your doctor judges it is necessary. If you have this medicine during pregnancy, your baby may need to have some monitoring after birth.

It is sensible to limit use of medication during pregnancy whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.


Mirtazapine passes into breast milk. You should only use this medicine if your doctor judges it is necessary.

It is sensible to limit use of medication during breastfeeding whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.


Before using this medicine, tell your prescriber of all the medicines you are taking including prescription medicines and medicines you have bought over the counter without a prescription. Tell your prescriber if you are taking vitamins or complementary remedies such as herbal products, as these can also interact with medicines.

If you are taking more than one medicine, these may interact with each other. Your prescriber may decide to use medicines which interact with each other if the benefit outweighs the risks. In these cases, the dose of your medicines may need to be adjusted or you may be monitored more closely.

The following medicines may interact with mirtazapine:

  • MAO inhibitors (antidepressants) or within two weeks after stopping these medicines
  • Other antidepressants (e.g. nefazodone) or medicines that contain serotonin or stimulate its production in the brain (e.g. SSRIs)
  • Medicines for infections, such as antibiotic or antifungal drugs (e.g. rifampicin, erythromycin, ketoconazole)
  • Medicines for epilepsy e.g. carbamazepine, phenytoin
  • Medicines for indigestion or stomach ulcers e.g. cimetidine
  • Medicines to prevent blood clotting e.g. warfarin
  • Medicines for the treatment of HIV e.g. lopinavir, indinavir, saquinavir
  • Sedatives and benzodiazepines e.g. lorazepam

This information does not contain all possible interactions. Therefore, tell your prescriber of all the products you are using before taking this medicine.

If you have a question or want to discuss anything about your medicine, speak to your local pharmacist.


If you take an overdose of mirtazapine (that is more than the doctor has prescribed), seek medical help immediately, either by calling a doctor or going to the nearest hospital casualty department. Always take the labelled medicine container with you, even if there are no tablets left. The most likely signs of overdose are drowsiness and disorientation.

If you think you, or someone you care for, might have accidentally taken more than the recommended dose of Mirtazapine or intentional overdose is suspected, contact your local hospital, GP or if in England call 111. In Scotland call NHS 24. In Wales, call NHS Direct Wales. In the case of medical emergencies, always dial 999.


If you forget to take a dose, just take your next tablet when it is due. Do not double the dose to make up for the missed dose.

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Source: Selected from data included with permission and copyrighted by Boots UK Limited. This copyrighted material is sourced from a licensed data provider and is not for distribution, except as may be authorised by the applicable terms of use.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgement of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse events, nor should it be construed to indicate that use of a particular medicine is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any medicine, changing any diet, or discontinuing any course of treatment.

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