Mirtazapine (active ingredient)

What is mirtazapine?

Mirtazapine is an antidepressant medicine.

What is mirtazapine used for?

Mirtazapine is mainly used to treat depression and/or to prevent it from occurring again.

Your doctor might prescribe mirtazapine for another reason. If you are unsure why you have been prescribed mirtazapine, ask your doctor.

How does mirtazapine work?

Medical experts believe mirtazapine works by balancing chemicals in the brain that are thought to affect mood and emotions. The chemicals involved are serotonin and noradrenaline.

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 you are 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 of mirtazapine?

Common side effects of mirtazapine include:

• drowsiness and tiredness
• increased appetite and weight gain
• fluid retention and swelling
• weakness

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
• unusual changes in behaviour
• suicidal thoughts

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.

If you are planning to stop taking mirtazapine, talk to your doctor. It is important not to stop mirtazapine suddenly, as this may cause symptoms such as nausea, headache, dizziness and anxiety.

When should I speak to 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 medication that may affect how your body reacts to mirtazapine
• become pregnant or start breastfeeding

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

Are there alternatives to mirtazapine?

Your doctor might prescribe another type of antidepressant medicine or suggest that you try psychological therapy, such as cognitive behaviour therapy (CBT).

There might be other approaches that can help, such as getting regular exercise and looking for pleasurable things to do each day. You can undertake CBT and other psychological treatments in combination with antidepressant medicine.