Remeron side effects and drug information

Remeron is a brand name for the prescription drug called Mirtazapine, and this medication is available in two forms, which are oral immediate-release tablet and orally dissolving tablet.

PubChem CID 4205
Trade Name Remeron
Bioavailability 50%
CAS ID 61337-67-5
Molar Mass 265.35 g/mol
Protein Binding 85%
Read up


For the immediate- release form, the brand name is Remeron, and for the orally dissolving, it is Remeron soltab. This drug is also available in a generic version and may be used as part of combination therapy.

Why It Is Used

Mirtazapine is used as a treatment for depression.

How It Works

This medication comes from a class of drugs known as antidepressants, and it works by increasing the amount of certain chemicals in the brain, which is serotonin and norepinephrine.  

Side Effects

Mirtazapine may cause various types of side effects. Still, the ones expected to be experienced drowsiness, feeling of restlessness, or having the feeling of agitation, especially during the 1st few weeks of treatment with this drug. Because of these potential side effects, the user of this drug is advised to avoid driving or operating machinery while under medication.  

More Common Side Effects

  • Having weird dreams
  • Dry mouth
  • Dizziness
  • Sleepiness
  • Constipation
  • Weight gain
  • Increase in appetite

This drug may also cause more severe side effects, and some of these include:

Suicidal thought or actions with symptoms such as:

  • Difficulty in sleeping
  • Increased activity
  • A feeling of restlessness or agitation
  • Feeling angry
  • Irritability
  • Unusual behavior or mood changes
  • Aggressive or violent actions
  • Anxiety 
  • Panic attacks
  • Having thoughts on suicide or dying
  • Attempting to commit suicide
  • Acting on dangerous instincts

Manic episodes that manifest the following symptoms:

  • Excessive irritability or happiness
  • Highly increased energy
  • Severe difficulty in sleeping
  • Having unusually big ideas
  • Talking faster than usual
  • Thoughts that seem to be racing
  • Careless behavior

If your immune system is weakened, Mirtazapine may decrease the white blood cells, which then could lead to infections such as:

  • Flu-like symptoms
  • Fever
  • Mouth or nose sores
  • Chills
  • Sore throat

Serotonin Syndrome comes with symptoms like:

  • High or low blood pressure
  • Nausea, vomiting or diarrhea
  • Feeling agitated
  • Coma
  • Hallucination
  • Difficulty thinking
  • Confusion
  • Fast heartbeat
  • Fever 
  • Sweating
  • Stiff muscles or twitching
  • Trouble in coordination

Eye Problems have these symptoms, such as:

  • Change in vision
  • Redness or swelling either in or around the eye
  • Pain in the eyes

Seizures and Low Sodium Levels in the Blood have symptoms that include:

  • Difficulty in concentrating
  • Confusion
  • Memory problems
  • Headache
  • Weakness or feeling unsteady

These side effects, though, are more likely to occur in seniors.

Severe Skin Reactions:

  • Blisters or reddening of the skin that is painful
  • Body or mouth ulcers
  • Severe rash that comes with swelling on the palm of hands or soles of the feet

Severe Allergic Reactions:

  • Presence of blisters, rash or hives that may or may not be accompanied with fever or joint pain
  • Difficulty in breathing
  • Swelling of the face, tongue, mouth or eyes

Increased Weight

  • High levels of cholesterol and triglycerides

Rhabdomyolysis, which is a severe muscle issue comes with these symptoms:

Indication and Dosage

Dosage for this drug is based on factors like age, a condition that is being treated, the severity of the condition, reaction to the 1st dose, and other medical conditions.

Drug Forms and Strength

For Mirtazapine, which is the generic version, its oral immediate-releasee tablet comes in 7.5mg/ 15mg/ 30mg and 45mg strength. As for its orally dissolving tablet, its strengths are 15mg/ 30mg and 45mg.

Remeron, the brand name version for the oral immediate-releasee tablet, comes in the strength of 15mg/ 30mg and 45mg. For the orally dissolving tablet, the brand name is Remeron Soltab, and the strength is 15mg/ 30mg and 45mg.


Dosage for Depression

Adults 18 to 64 years old

  • Starting dosage is 15mg once a day and taken at night time
  • the dosage will be gradually increased by the doctor every 1 to 2 weeks
  • maximum dose allowed per day is 45mg

Child 0 to 17 years old

There is no confirmation yet about its safety on those who are younger than 18 years old.

Senior 65 and up

They may start on a lowered dose or be given a different dosing schedule to help keep the levels of the drug for depression from building up too much.

Drug Interaction

It may interact with other medications, including vitamins and herbal.

Warning and Precautions

Allergy Warnings:

  • difficulty in breathing
  • severe rash with swelling on palms and soles
  • itchy hives or blisters that may come with or without fever or joint pain
  • blisters on mouth or body and painful reddening of the skin
  • swelling of the face, tongue, eyes, mouth

Alcohol Interaction:

If used with alcohol, there may be an increased risk of sleepiness and may affect decision making and thinking.


Warnings for People with Certain Health Conditions

For those with mania or bipolar disorder:

May provoke manic episodes.

For those with seizures:

May make the condition worse.

For those with heart problems:

May cause a decrease in blood pressure and aggravate heart conditions.

For those with eye problems:

May provoke glaucoma attack and may dilate pupils.

For those with kidney problems:

The drug may be stuck in the body.

For those with liver problems:

The body may not process this neprinol drug well.

Warnings for Other Groups:

For pregnant women:

May cause adverse effects to the fetus based on animal research, but there is not enough study on the human fetus.

For breastfeeding moms:

The drug may pass into the breastmilk and cause side effects to the baby.

For seniors:

May cause drowsiness or confusion.

For children:

Still unknown if safe for those younger than 18 years old.

Overdose and Contraindications

This medication may interact with:

  • MAOI inhibitors and risk for serotonin syndrome may be increased
  • Linezolid and intravenous methylene blue
  • Benzodiazepines
  • Triptans
  • Lithium
  • Serotonergic drugs
  • Antipsychotics, antibiotics, and drugs that affect heart rhythm
  • Warfarin
  • Drugs that increase or decrease the amount of Mirtazapine in the body

Clinical Pharmacology

It is used for long term treatment and should not be stopped suddenly as withdrawal symptoms may occur. Take the medication regularly and consistently.

Medication Guide

Read the guide before taking this drug and take exactly as prescribed by the doctor.