Mirtazapine is an antidepressant medicine. It's used to treat depression and sometimes obsessive compulsive disorder and anxiety disorders.
You'll usually take mirtazapine once a day. It's best to take mirtazapine before you go to bed as it can make you sleepy.
Use this medication regularly in order to get the most benefit from it. To help you remember, take it at the same time each day. It may take 1 to 4 weeks to notice improvement in your symptoms. Do not increase your dose or take it more often than prescribed.
Tell your doctor if your condition does not get better or if it gets worse.
Keep taking this medication even if you feel well. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when you suddenly stop this drug. Your dose may need to be gradually decreased.
Mirtazapine can be taken with or without food.
The usual starting dose for mirtazapine is 15 to 30mg a day. This can be increased up to 45mg a day.
If you have problems with your liver or kidneys your doctor might prescribe a lower dose.
If you take mirtazapine once a day and miss a dose, skip it and take the next dose at the normal time. Do not take a double dose to make up for a forgotten dose.
your morning dose – take it together with your evening dose
your evening dose – do not take it with the next morning dose. Instead skip the missed dose, and then continue the next day with your normal morning and evening doses
both doses – skip the missed doses. Continue the next day with your normal morning and evening doses. Do not take an extra dose to make up for a missed dose
If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
Like all medicines, mirtazapine can cause side effects in some people, but many people have no side effects or only minor ones.
Some of the common side effects of mirtazapine will gradually improve as your body gets used to it.
These side effects happen in more than 1 in 100 people.
Keep taking the medicine, but tell your doctor or pharmacist if these side effects bother you or don't go away:
Serious side effects are rare and happen in less than 1 in 10,000 people when taking mirtazapine.
Call your doctor straight away if you experience:
In rare cases, it's possible to have a serious allergic (anaphylaxis) reaction to mirtazapine.
It's important for you and your baby that you stay well during your pregnancy.
If you become pregnant while taking mirtazapine speak to your doctor. Do not stop taking your medicine unless your doctor tells you to.
Mirtazapine has been linked to a very small increased risk of problems for your unborn baby.
But if your depression is not treated during pregnancy this can also increase the chance of problems.
You may take mirtazapine during pregnancy if you need it to remain well. Your doctor can explain the risks and the benefits, and will help you decide which treatment is best for you and your baby.
If your doctor or health visitor says your baby is healthy, mirtazapine can be used during breastfeeding. It has been used by many breastfeeding mothers usually without any problems.
Mirtazapine passes into breast milk in small amounts. It has been linked with side effects in very few breastfed babies.
It's important to continue taking mirtazapine to keep you well. Breastfeeding will also benefit both you and your baby.
If you notice that your baby isn't feeding as well as usual, or seems unusually sleepy, or if you have any other concerns about your baby, talk to your health visitor or doctor as soon as possible.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before and after treatment with this medication. Ask your doctor when to start or stop taking this medication.
The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), tryptophan, among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.
Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana (cannabis), antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), and opioid pain relievers (such as codeine, hydrocodone).
Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.