Mirtazapine (Remeron): Does It Work for insomnia?

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Are you searching for the antidepressant medication mirtazapine and its effects in the treatment of insomnia (sleeping difficulties)? Here is an in-depth article about mirtazapine and how it is used for relieving insomnia.

Mirtazapine, also known as Remeron, is a drug used to treat major depressive disorders. It is categorized under the class of atypical antidepressants.

Mirtazapine is used to treat depression, anxiety, and OCD (obsessive compulsive disorders). It is also an off-label drug treatment for relieving insomnia and increasing appetite.

Research studied the effect of mirtazapine on two groups. One group had depression with insomnia, while the other was suffering only from insomnia. The study revealed that low-dose mirtazapine was effective in treating insomnia in both groups, whether they had depression or didn’t have depression.

Similarly, in another study, insomnia was induced in people with traffic noise, and they were administered a low dose of 7 mg mirtazapine to check the effects of the medicine. The drug improved both the sleep quality and sleep time in the individuals.

Hence, research and studies have proven that mirtazapine is effective for improving both the quality and quantity of sleep.

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What Is Mirtazapine Used For?

Mirtazapine acts on the central nervous system. Hence, the drug is used to treat all major disorders of the brain.

For example, mirtazapine is widely effective for treating mood disorders like depression, anxiety, or insomnia.

Mirtazapine is used to treat the following conditions:

1. Depression

Depression, also called a major depressive disorder, is a serious medical illness that affects a person’s mood and mental well-being. It causes a persistent feeling of sadness, grief, and loss of interest in daily activities.

To treat depression, mirtazapine alters the functioning of the central nervous system by balancing certain chemicals in the brain.

2. Anxiety

Anxiety is the constant feeling of fear, stress, and worry about the future or the unknown. Mirtazapine calms and relaxes the brain to treat anxiety.

3. OCD

OCD or obsessive-compulsive disorder is another mental health disorder that brings unwanted, uncontrollable, and recurring thoughts in a person, which leads to anxious and distressed behavior. Mirtazapine is also given for treating obsessive-compulsive disorders.

4. Insomnia

Insomnia is a sleep disorder in which a person struggles to stay or fall asleep. Mirtazapine has sedative effects at low doses and is used to treat insomnia.

5. Appetite Stimulant

One of the most common actions of mirtazapine is that it increases appetite, thus leading to weight gain. Mirtazapine is not approved by the US FDA to be used as an appetite stimulant, but the drug is sometimes utilized as an off-label therapy to increase appetite and gain weight.

How Does Mirtazapine Work? Mechanism Of Action Of Mirtazapine

Mirtazapine works by increasing the concentration of neurotransmitters (chemical messengers), i.e., norepinephrine and serotonin, in your brain. These neurotransmitters are the happy chemicals of our brain.

They are mood stabilizers and develop a feeling of well-being. Hence, mirtazapine is an antidepressant medication that increases the concentration of these mood stabilizers to relieve depression.

How Does Mirtazapine Improve Sleep? Mirtazapine For Sleep

Although mirtazapine is an antidepressant drug, studies and research have proven that low doses of mirtazapine have sedating effects and it is an effective therapy to relieve insomnia (sleeping difficulties). Most importantly, the sedative effects of mirtazapine are more significant at low doses but are diminished at high doses.

Mirtazapine has shown potential effects in different phases of sleep.

  • It reduces the duration of early and light stages of sleep.
  • It increases deep sleep.
  • Mirtazapine has also been shown to increase the total sleep time.
  • Because of the sedating effects of mirtazapine, it can also cause daytime drowsiness.

Mirtazapine reduces the time to fall asleep, decreases awakenings in the middle of the night, and improves the overall quality of sleep. The drug is also helpful in relieving insomnia caused by depression and anxiety.

How Long Does It Take For Mirtazapine To Work?

Unlike benzodiazepines, all antidepressants take a few weeks to work. And as mirtazapine is an antidepressant, it may take around 4 to 6 weeks to work and show apparent beneficial effects.

When mirtazapine is taken at low doses for insomnia, it takes around 1 to 2 weeks to show response. But the effect may vary from patient to patient. Some patients may experience the response from the first dose, while some patients might experience the response gradually.

However, mirtazapine is not a long-term solution for insomnia. The drug’s sedative effects may decrease with time as your body gets used to the drug. Hence, it is advisable to focus on treating the underlying cause of insomnia along with taking mirtazapine.

Mirtazapine Side Effects

The common side effects of mirtazapine go away with time. So, you don’t need to worry about them as they usually occur. However, if they persist or become intolerable, consult your pharmacist to switch your medication.

The side effects of mirtazapine vary from patient to patient.

Side effects for mirtazapine include:

  • Increased appetite
  • Weight gain
  • Dry mouth
  • Drowsiness and dizziness
  • Nausea and Vomiting
  • Diarrhea
  • Headache
  • Daytime drowsiness
  • Restless leg syndrome

The severe side effects for mirtazapine include:

  • Hallucinations
  • Heart problems
  • Loss of coordination
  • Memory problems
  • Fever

Mirtazapine Side Effects On the Elderly

Elderly patients are more likely to experience mirtazapine side effects like confusion or drowsiness. Hence, they should be given a lower dose at the start of therapy to determine how your body responds to the drug.

Side effects, including the following, are more likely to be experienced by elderly patients taking mirtazapine:

  • Nausea and vomiting
  • Tiredness
  • Confusion
  • Headache
  • Dizziness and drowsiness
  • GIT disturbances

Mirtazapine In Pregnancy

The US FDA classifies mirtazapine as a pregnancy category C drug. This means the drug shows adverse effects on the fetus in animal studies, but there are no well-controlled or adequate findings in humans. However, the risk for congenital malformations in the first trimester of pregnancy has been concerned with the use of mirtazapine.

Hence, mirtazapine should be taken in pregnancy if clearly needed or if its benefits outweigh the risk factors. Inform your doctor if you are pregnant or planning to become pregnant before taking mirtazapine.

Can You Take Mirtazapine In Breastfeeding For Insomnia?

If your baby is healthy and your doctor allows you to take mirtazapine while breastfeeding, you can take the drug. Mirtazapine is excreted in breastmilk but in small amounts, and no prominent harm is seen with the use of the drug.

But remember to keep a check on your baby while using the drug during breastfeeding. If you notice any unusual change or restlessness and irritability in your baby, consult your healthcare professional immediately.

How To Manage Mirtazapine Side Effects?

Here are some tips for managing the common side effects of mirtazapine:

  • Take mirtazapine exactly as prescribed by your doctor.
  • Do not take alcohol when on mirtazapine therapy.
  • You can take mirtazapine with or without food. If you face nausea, vomiting, or GIT problems from mirtazapine, take the drug before, during or after your meal.
  • To prevent weight gain, eat a healthy diet and satisfy your cravings by filling your plate with proteins instead of carbs.
  • Take mirtazapine at the same time every day, i.e., at bedtime.
  • Do not drive, operate machinery, or engage in alerting activities after taking mirtazapine, as it can cause drowsiness and increase the risk of injuries.
  • For managing mirtazapine side effects of dry mouth, take sips of water and juices throughout the day. You can also use mouthwash before bedtime. Moreover, to control diarrhea and GIT disturbances, maintain your hygiene.
  • Do not stop taking mirtazapine unless recommended by your doctor or pharmacist.
  • Tell your doctor about your drug history and pre-existing medical condition before taking mirtazapine.

How To Take Mirtazapine?

Take mirtazapine as recommended by your doctor. For insomnia, take mirtazapine once daily before bedtime.

Start with a low dose by consulting with your doctor. To treat insomnia, the drug is most effective if taken at doses from 5 to 10 mg before bedtime.

Mirtazapine Strength And Doses

Mirtazapine is available in both tablet and liquid dosage forms. It comes in the following strengths:

  • 15 mg
  • 30 mg
  • 45 mg

Dose Of Mirtazapine For Sleep

The starting dose of mirtazapine for sleep is 3.75 to 7.5 mg before bedtime. The dose may be increased up to 15 mg per day and taken at bedtime for insomnia or insomnia accompanied by depression.

study in the US trial revealed that low doses of mirtazapine from 5 to 10 mg were more effective in relieving insomnia than doses from 15 to 20 mg. The research also showed that sedating effects of mirtazapine were more stronger in the first few weeks of treatment.

Dose Of Mirtazapine For Depression Or Anxiety

The standard dose of mirtazapine for depression or anxiety is 15 to 30 mg per day given at bedtime for two to four weeks. If necessary, the dose may be 45 mg per day given once daily or in two divided doses.

Mirtazapine Drug And Food Interactions

Alcohol and high cholesterol levels are known to interact with mirtazapine. Alcohol increases the nervous system side effects of mirtazapine like drowsiness, dizziness, and difficulty concentrating. Impairment in thinking and judgment is also seen when mirtazapine and alcohol are taken together.

Hence, it is recommended to avoid alcohol or limit its intake when you are on mirtazapine therapy. Do not take alcohol with the drug or after taking mirtazapine.

The levels of mirtazapine in the body can increase in patients having elevated cholesterol or triglyceride levels. Hence, close monitoring of cholesterol levels or dose adjustment of mirtazapine is recommended in patients with high cholesterol during mirtazapine therapy.

The drug interactions of mirtazapine include:

Mirtazapine can cause serotonin syndrome if taken with the following drugs:

  • Fentanyl
  • Buspirone
  • Lithium
  • Tryptophan
  • Sumatriptan
  • Rizatriptan
  • Tramadol


Q. What is mirtazapine?

Mirtazapine is a prescription-based medication that comes under the class of atypical antidepressants. It increases the concentration of happy chemicals in your brain, i.e. serotonin and norepinephrine.

Q. What are the most common side effects of mirtazapine?

The most common side effects of mirtazapine go away on their own as you get used to the drug. They include:

  • Drowsiness and dizziness
  • Sleepiness
  • Increased appetite
  • Lightheadedness
  • Weight gain
  • Dry mouth
  • Constipation

Q. What is the drug mirtazapine used for?

Mirtazapine is mainly used for treating depression and anxiety. Its off-label uses include increasing appetite and relieving insomnia.

Q. Is mirtazapine a sleeping pill?

No. Mirtazapine is not a sleeping pill. Only its low-dose sedative effects are used to relieve insomnia. Moreover, unlike other drugs that are primarily used for insomnia, mirtazapine does not have a high potential for abuse and addiction.

Q. How long does it take to get used to taking mirtazapine?

It may take a few weeks, i.e., from 2 to 4 weeks to get used to the drug. But the duration may vary from patient to patient. Some people may get used to the drug in the first week, while some may require 2 to 4 weeks to get a response or get used to its side effects.

Q. What should I monitor while taking mirtazapine?

When taking mirtazapine, monitor for any extreme, persistent, or unusual side effects. The common side effects go away on their own, but if they persist or become uncontrollable, consult your doctor. Also, monitor for symptoms like breathing difficulties, hallucinations, fast heart rate, excessive dizziness, sweating, and muscle stiffness.

Q. How long does it take mirtazapine to work for sleep?

Mirtazapine takes around 1 to 2 weeks to work for sleep.


Mirtazapine is an antidepressant drug that comes under the brand name Remeron. The drug is mainly indicated for treating anxiety, depression, and OCD. With that, research and studies have proven that low doses of mirtazapine are effective for treating insomnia. Doses of up to 5 to 10 mg of mirtazapine have sedative effects and can relieve insomnia.

Commonly, the drug is prescribed to be taken for once-daily dosing at bedtime. Side effects such as weight gain and drowsiness are common with mirtazapine. Hence, it is recommended to avoid driving, engaging in alerting activities, or drinking alcohol while taking mirtazapine.

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