Mirtazapine

1 medicine

Mirtazapine is an antidepressant often chosen for people with depression alongside poor sleep or appetite loss, because sedation and weight gain are its two defining, dose-related side effects.

Remeron

Mirtazapine

7.5/15/30mg

Remeron is a antidepressants medication containing Mirtazapine, available as 7.5/15/30mg tablets.

from $0.56 / tablet View

Key facts

  • Mirtazapine is an antidepressant used for major depressive disorder, often chosen when insomnia or poor appetite accompany low mood.
  • You take it once daily in the evening; sleep and appetite often improve within the first 1 to 2 weeks, while full mood benefits take 2 to 4 weeks.
  • Sedation and weight gain are mirtazapine's defining side effects. Sedation is usually stronger at lower doses; some prescribers raise the dose specifically to reduce daytime sleepiness.
  • In people under 25, mirtazapine can increase suicidal thoughts and behaviour, especially early in treatment. Seek urgent care for a sore throat and fever together, which can signal a drop in white blood cells.

What mirtazapine treats

Mirtazapine treats major depressive disorder. Because it typically increases appetite and promotes sleep, it is often used for people whose depression comes with significant weight loss or insomnia.

How mirtazapine works

Mirtazapine blocks certain receptors that normally limit the release of serotonin and norepinephrine, chemical messengers involved in mood, so more of both circulate. It also blocks histamine receptors, which produces its sedative and appetite-stimulating effects, especially early in treatment.

Before you take it

  • Never take mirtazapine within 14 days of a monoamine oxidase inhibitor (MAOI); the combination can cause serotonin syndrome, which can be fatal.
  • Tell your prescriber about liver or kidney disease, a seizure history, or other sedating medicines and alcohol, which combine with mirtazapine to increase drowsiness and impair driving or operating machinery.
  • Report a sore throat, fever, mouth ulcers or other signs of infection promptly. Mirtazapine rarely lowers white blood cell counts, which can weaken your ability to fight infection.
  • Never stop mirtazapine suddenly. Taper the dose down gradually under medical guidance to avoid nausea, dizziness and flu-like withdrawal symptoms.

Side effects

Common effects: drowsiness, increased appetite and weight gain, dry mouth and constipation.

Stop and seek urgent medical care for any of these:

  • New or worsening suicidal thoughts, especially if you are under 25.
  • A sore throat and fever occurring together, or other signs of infection.
  • Agitation, high fever, muscle twitching or confusion (serotonin syndrome).
  • Severe rash, swelling or difficulty breathing.

Safety essentials

  • Sedation and weight gain are expected with mirtazapine. Avoid alcohol and other sedating substances, take it in the evening, and do not drive or use machinery until you know how it affects you.
  • This class carries a warning for increased suicidal thinking in people under 25, particularly in the first weeks of treatment.
  • Never combine mirtazapine with an MAOI, and taper off slowly rather than stopping abruptly.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.