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Drug Class: Commonly Known As: Category:
Serotonin and Noradrenaline Reuptake Inhibitors (SNRI) remeron Adult

Mirtazapine - What is it for

This medicine is an antidepressant.

It is used to treat conditions such as:

  • Low mood (depression)

It may be given to you for other reasons. Do check with your doctor what you are taking this for.

Mirtazapine - Side Effects, Precautions, and Contraindications

What side effects can Mirtazapine cause?

Potential side effects

All medicines may cause side effects. However, many people do not experience them.

Most of the side effects listed here will improve with time. Speak with your doctor or pharmacist if they persist, become bothersome or worsen.

Side effectsWhat to do about it
Increased appetiteMaintain a healthy diet. Exercise regularly.

Do not drive or operate any machinery until you have experienced how this medicine affects you.

Discuss with your doctor if you can take your medicine at a different time of the day. 

DizzinessGet up slowly from a lying or sitting position.
Dry mouthSip water regularly. Sucking on sugar-free sweets or ice chips may help alleviate this symptom. Avoid caffeine as it may worsen dry mouth.


Serious side effects

Seek medical help as soon as possible if you have any of the following signs or symptoms.

  • Allergic reaction; including symptoms such as rashes, swelling of lips/face/throat, difficulty breathing and/or swollen, red blistered or peeling skin with red irritated eyes or sores in mouth, throat, nose or eyes.
  • On rare occasions this medicine may cause a condition known as serotonin syndrome. This may cause symptoms including, but not limited to confusion, hallucination, agitation, altered mental state, fever, flushing, twitching, shivering or sweating. Report any unusual symptoms which arise immediately to your doctor.
  • Worsening of your mood or other psychiatric condition including new or worsening thoughts of self-harm.
  • On rare occasions this drug affects the blood. Report any unusual fever, sore throat, inflammation of the tongue or other signs of infection during treatment to your doctor for further investigation.
  • Irregular heart rhythm/ heart palpitations

Take note that the side effects listed here are not exhaustive. Do seek medical attention if you have other symptoms that you think may be related to this medicine.

Before taking Mirtazapine, what precautions must I follow?

What do I need to tell my doctor before I take this medicine? Inform your doctor if you have:

  • Drug allergies.
  • Pre-existing medical conditions such as fits (seizures), bipolar disorders or mania (unusually high or excited mood, being much more active or having more energy than usual), cardiac conditions (including a history of irregular heart beat), phenylketonuria and low sodium levels in the blood.
  • Whether you are taking any other medicine, supplements or traditional medicines. Some of them may affect how this medicine works.
  • If you have taken any other antidepressants in the last 2 weeks.
  • For women: tell your doctor if you are pregnant or breast-feeding or have plans to become pregnant. If you are pregnant and/or breastfeeding, your doctor would have discussed the potential benefits and side-effects of starting or continueing this medicine but should you have further questions or concerns, do consult your doctor.

What food or medicine must I avoid when I take Mirtazapine?

  • ​Avoid alcohol while taking this medicine.
  • This medicine may interact with other medicines. If you intend to take any over the counter medicine, supplement, herbal remedy or traditional Chinese medicine, consult your doctor or healthcare professional first to confirm that it is safe to take with mirtazapine.

Mirtazapine - Dosage and How to Use

How should Mirtazapine be used?

Oral disintegrating/dispersible tablet

Take this medicine exactly as prescribed by your doctor. Follow the instructions on the medicine label or as advised by the pharmacist.

Mirtazapine may be taken with or without food. Place the tablet on the tongue. This medicine dissolves once you place it inside your mouth and can be swallowed without water.

 How to remove the tablets from the blister pack

1. Make sure your hands are dry before handling the tablets as it dissolves when in contact with water. 

2. Cut out a square containing a tablet, along the dotted line.

3. Peel off the backing of the blister pack, starting from the corner as indicated by an arrow. Do not push against the tablet pocket to prevent crushing the tablet.

4. Consume the tablet as soon as possible. Do not remove the tablets too early from the blister pack.


This medicine may not have an effect immediately. It may take up to a few weeks before it can exert its full effects. Continue taking it regularly to benefit from it.

Do not stop taking the medicine even after you feel better. Your symptoms may return if this medicine is stopped too early. Check with your doctor on the duration of treatment that is suitable for you.

Do not stop taking this medicine abruptly or change the dose without consulting your doctor. You may experience unpleasant side effects if this medicine is stopped suddenly. Stopping this medicine suddenly after taking it long for a long time may lead to symptoms such as nausea, headache, insomnia, anxiety.

Avoid taking alcohol while you are on this medicine. This medicine may impair your ability to perform tasks that require alertness such as driving and operating machinery.

Contact your doctor immediately should you or your child (patient) experience new or worsening thoughts of self-harm, increased anxiety, aggressive behaviour or other changes of mood.


What should I do if I miss a dose?

Take the missed dose as soon as you remember. However, if it is close to the time for your next dose, skip the missed dose and take the next one at your usual timing.

Do not take 2 doses at the same time or extra doses.

What should I do if I overdose?

​If you have taken more doses then prescribed by your doctor, consult a healthcare professional immediately.


Mirtazapine - Handling and Storage

How should I handle Mirtazapine safely?

How should I store Mirtazapine?

Keep away from children;#Keep in a cool, dry place, away from direct sunlight;#Store at room temperature;#Store this medicine at room temperature and out of reach of children.

How should I dispose of Mirtazapine safely?

​Discard any unused or expired medicine. If unsure how to safely dispose of your medicine safely, consult your pharmacist or doctor.

Mirtazapine - Additional Information

​What are the things I need to know or look out for while on this medicine?

  • Avoid driving or any other activities that requires concentration until you see how this drug affects you.
  • Inform your other healthcare professionals that you are on this medicine as well.
  • Discuss with your doctor or pharmacist before you take any other medicine or natural products.
  • Do not share your medicines with others.
  • Consult your doctor or pharmacist if you have any questions about your medicines.
  • Updated on
  • Article contributed by Changi General Hospital Changi General Hospital, KK Women's and Children's Hospital

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