Avoid alcohol while taking mirtazapine, as it can make you drowsy, dizzy, and less alert. Do not drive or operate heavy machinery until you know how it affects you.

What is mirtazapine?

Mirtazapine is an antidepressant medicine. It belongs to a class of medicine called tetracyclic antidepressants. Mirtazapine affects the levels of chemicals in your central nervous system to treat depression.

Mirtazapine is known for its sedative effects, which can help improve sleep. It may also stimulate appetite, which may help people who experience weight loss due to depression.

How does mirtazapine work?

Mirtazapine works by balancing chemicals in the brain that are thought to affect mood and emotions. It increases the levels of chemicals called serotonin and noradrenaline. Low levels of these chemicals are thought to contribute to depression.

What is mirtazapine used for?

Mirtazapine is used to treat episodes of depression and to prevent it from occurring again. It has also been shown to have other effects including:

• sedation
• increased appetite
• improved sleep quality

Mirtazapine is sometimes prescribed to help:

• generalised anxiety disorder
• post-traumatic stress disorder (PTSD)
• anxiety and irritability during cannabis withdrawal

Your doctor might prescribe mirtazapine for another reason. Ask your doctor if you are unsure why they prescribed mirtazapine for you.

What forms of mirtazapine are available?

Mirtazapine is the name of the active ingredient. It is available in many different brands, which have different:

• names
• appearances (size, shape or colour)
• forms (tablets and disintegrating tablets)
• packaging

No matter which brand is prescribed, mirtazapine works in the same way to treat depression.

In Australia, mirtazapine is only available with a doctor's prescription.

What are the possible side effects or risks of mirtazapine?

All medicines have benefits, and they also have the risk of side effects. If you have any concerns speak to your doctor.

Common side effects of mirtazapine include:

• drowsiness and tiredness
• increased appetite and weight gain
• fluid retention and swollen ankles or feet
• weakness
• vivid nightmares

Tell your doctor if you have rare but serious side effects of mirtazapine, which include:

• itching or a skin rash
• feeling extremely restless and an overwhelming urge to always be moving (hyperkinesia)
• unusual changes in behaviour
• seizures, muscle weakness or cramps
• dizziness on standing (orthostatic hypotension)
• eye pain
• suicidal thoughts

Each person responds to medicines differently. Just because a side effect is listed does not mean you will experience it. Even if you experience a side effect, you and your doctor will need to weigh up the medicine's benefits against its risks before deciding what to do. This could be deciding to:

• make no changes
• change the dose
• switch to another treatment option

This is not a full list of side effects for mirtazapine. For more information on the side effects and risks, read the Consumer Medicine Information (CMI) for the brand of mirtazapine you are taking, or talk to your doctor or pharmacist.

How do I take mirtazapine?

Your doctor or pharmacist will tell you how to take mirtazapine. Make sure to follow their instructions carefully.

Don't change your dose or stop taking mirtazapine without talking to your doctor. Sometimes it takes a while before you start to feel the effects of antidepressants.

Try to take mirtazapine at the same time every day. It does not matter if it is taken with or without food.

If you take too much mirtazapine (overdose), call your doctor or the Poisons Information Line on 13 11 26, even if you don't feel any side effects.

What should I be careful of when taking mirtazapine?

Mirtazapine can make the effects of alcohol and sedative medicines such as benzodiazepines stronger. Avoid alcohol when taking mirtazapine and speak to your doctor if you have also been prescribed a benzodiazepine medicine, such as diazepam. Drinking alcohol while taking mirtazapine can also make you feel sleepy and less alert.

Mirtazapine may make you drowsy or dizzy, and reduce your ability to concentrate. Be careful when driving or operating heavy machinery until you understand how the medicine affects you.

If you are planning to stop taking mirtazapine, talk to your doctor first. It is important not to stop mirtazapine suddenly, as this may cause symptoms such as:

• nausea
• headache
• dizziness
• anxiety

When should I see my doctor?

Speak to your doctor if you:

• feel that taking the medicine has not helped reduce your symptoms of depression
• experience side effects that trouble you
• have signs of an allergic reaction
• have a health condition or are taking medicines that may affect how your body reacts to mirtazapine
• become pregnant, are planning a pregnancy or start breastfeeding

Some people, especially young people, can experience an increase in thoughts of suicide or self-harm when starting to take antidepressant medicines. This generally resolves over time as the medicine starts to work.

If someone you care about is starting antidepressants, it's a good idea to look out for signs of suicidal thoughts or plans. If you are starting antidepressants yourself, think about what you can do to keep yourself safe if you start thinking about suicide.

Read the CMI in the package for full details about when to speak with your doctor before or after you have started taking mirtazapine.

If you don't feel that mirtazapine is helping your symptoms, your doctor might prescribe another type of antidepressant medicine. They may suggest that you try psychological therapy, such as cognitive behaviour therapy (CBT).

Other approaches that can help include getting regular exercise and looking for pleasurable things to do each day. Ask your doctor about CBT and other psychological treatments you can try in combination with antidepressant medicine.

Resources and support

It is important to ask about your treatment or medicines to help you understand your options. Read our guide to important questions to ask your pharmacist or doctor before taking a medicine.

You can also visit healthdirect's list of medicines that contain mirtazapine to read the CMI for the brand of mirtazapine prescribed.

Support is available if you, or someone you know, has depression:

• Visit Beyond Blue or call 1300 22 4636 for information and support for people with depression and anxiety, as well as their families.
• Visit SANE on 1800 187 263 for information and support for people with mental health conditions, as well as their friends, families and communities.
• Read more on mental health helplines.

Do you prefer to read in languages other than English?

Embrace Mental Health has health information about depression in many community languages.

If you need mental health support in your language, contact Medicare Mental Health through the Translating and Interpreting Service (TIS National). TIS National covers more than 100 languages for the cost of a local call:

• Call TIS National on 131 450.
• Tell the operator the language you speak.
• Ask the interpreter to call Medicare Mental Health on 1800 595 212.

Looking for information for Aboriginal and/or Torres Strait Islander people?

You can find out what you need to know about your antidepressant in the NPS MedicineWise factsheet.