Patient handout
Mirtazapine (Remeron)
You have been prescribed mirtazapine. This page explains what it is, what to expect, and when to call.
What it is
Mirtazapine is an antidepressant that works differently from SSRIs and SNRIs. It is often chosen when depression comes with poor sleep, poor appetite, or weight loss, because it is sedating and increases appetite. It causes fewer sexual side effects and less nausea than SSRIs.
How to take it
- Take it once a day at bedtime.
- With or without food. The dissolving tablet goes on the tongue without water.
- If you miss a dose, skip it and take the next one at bedtime. Do not take it in the morning or double up.
- Lower doses are often more sedating than higher ones, so do not assume a higher dose means more sleepiness.
What to expect, and when
- First nights: sleep usually improves right away. Grogginess the next morning is common at first and typically fades within a week or two.
- Week 2 to 4: appetite and mood often begin to improve.
- Week 4 to 8: full benefit at the right dose.
- Plan to stay on it for at least six to twelve months after you feel well.
Common side effects
Sleepiness, increased appetite and weight gain, dry mouth, constipation, and dizziness. Weight gain is the main long-term trade-off and is worth tracking from the start.
Call the office the same day if
- Fever, sore throat, mouth sores, or other signs of infection that do not clear (rarely, mirtazapine lowers white blood cells)
- New or worsening thoughts of hurting yourself, especially early on or after a dose change (particularly under age 25)
- Unusual restlessness, racing thoughts, or little need for sleep
- Fever with agitation, muscle twitching, or confusion, especially with another antidepressant (possible serotonin syndrome)
- Rash, swelling, or trouble breathing (call 911)
Stopping
Stopping mirtazapine suddenly can cause anxiety, insomnia, nausea, and irritability. Do not stop on your own. We taper gradually together.
Good to know
- Do not drive until you know how sleepy it makes you. Avoid alcohol and other sedatives.
- Weigh yourself weekly for the first two months and tell us about steady gain; adjustments are possible.
- Tell other prescribers and your pharmacist. If you are pregnant, planning pregnancy, or breastfeeding, tell us.
Questions about this medication?
Alice Tran Psychiatric Care · 3060 Williams Drive, Suite 300, Fairfax, VA 22031
Call: (703) 791-9099 · Text: (703) 791-9031 · info@alicetrannp.com · alicetrannp.com
This handout is for education and is not a substitute for the instructions you received at your visit. Follow the dose on your prescription label. If anything here differs from what you were told, call the office. In an emergency, call 911. If you are in crisis, call or text 988.