Mirtazapine (Remeron®)
Pronounce: mir-TAZ-a-peen
Classification: Anti-Depressant, Alpha-2 Antagonist
About Mirtazapine (Remeron®)
Mirtazapine is a medication used to treat major depressive disorder in adults. Possible side effects of this medication are increased appetite, which can cause weight gain, and sleepiness. Because of these side effects, this medication is sometimes used to help patients who have problems with eating or sleeping.
How to take Mirtazapine
This medication comes in both a tablet and an orally disintegrating tablet form. This medication is taken by mouth once daily, often at night-time. The tablet can be taken with or without food. If you are taking the orally disintegrating tablet version, make sure to take the medication right away after removing it from the blister pack. The whole disintegrating tablet should be placed on the tongue and allowed to disintegrate (melt or dissolve) without chewing or crushing it. Once it has disintegrated, you should swallow the saliva in your mouth.
Talk with you provider before stopping this medication. You could have serious side effects if you just stop taking it. Your provider will help create a plan to slowly lower your dose safely.
The blood levels of this medication can be affected by certain foods and medications, so they should be avoided. These include: amphetamines, buprenorphine, buspirone, carbamazepine, cimetidine, clarithromycin, dabrafenib, enzalutamide, idelalisib, ketoconazole, linezolid, lithium, mitotane, opioid and non-opioid pain medications, phenytoin, rasagiline, rifampin, selegiline, tryptophan, and St. John’s Wort, among others. Be sure to tell your provider about all medications and supplements you take.
Don't drink alcohol while taking this medication.
Storage and Handling
Store this medication in the original container at room temperature. Keep this medication out of reach of children and pets.
Where Do I Get This Medication?
Some cancer medications are only available through specialty pharmacies. Your provider or pharmacist will start this process. Your insurance plan may also affect where you can get your medication. Call your prescription plan provider to find out which specialty pharmacies are in-network.
Insurance Information
This medication may be covered by your prescription plan. If you qualify, you may be able to get financial help through patient assistance programs (PAP). Co-pay cards may also be available to lower your out-of-pocket cost if you have commercial (not Medicare/Medicaid/Tricare) insurance. Your pharmacist, social worker, or navigator can help find resources for financial support.
Possible Side Effects
These are some of the most common or most serious side effects of this medication. Talk with your provider about the side effects you are having and how they can be managed.
Suicidal Behavior/Ideation
This medication can raise your risk of suicidal thoughts and behaviors. Your caregiver should know about this side effect. Tell your provider right away if you have:
- Changes in mood.
- Changes in behavior.
- Suicidal thoughts or actions (self-harm).
Mood Changes
Mania can be another possible side effect of this medication. Mania is the opposite of depression and is a state of abnormal excitement and energy level. It is important to be aware of any changes to your mood and to call your provider right away to discuss these changes.
Increased Appetite
This medication can cause an increase in appetite that can help with maintaining and gaining weight. This can be helpful if you are having trouble maintaining proper nutrition and weight.
Somnolence
This medicine can make you very sleepy. You might feel foggy, have trouble thinking clearly, or find it hard to make decisions. Don't drive or use heavy machinery when you first start taking it, until you know how it affects you.
Reproductive Concerns
Talk with your provider before becoming pregnant or getting someone else pregnant. You should also talk with your provider before breastfeeding while receiving this medication.
Important but Less Common Side Effects
Agranulocytosis
This is a low white blood cell count that causes neutropenia. Symptoms can include fever and infection. You will have your white blood cell count monitored and you should contact your provider if you develop a new cough, sore throat, fever, urgency or pain with urination, or any other sign of infection.
Serotonin Syndrome
This side effect can cause a fever, sweating, dilated pupils, diarrhea, higher than normal heart rate, changes in blood pressure, seizures, and agitation. Call your provider right away if you experience any of these side effects.
Angle-Closure Glaucoma
This medication can cause your pupils to dilate which in some people can lead to angle-closure glaucoma. You may want to have an exam with an eye doctor to determine if this may be an issue for you.
QT Prolongation with Torsades de pointes (TdP)
QT prolongation is when your heart is not working how it should, causing abnormal heartbeats or an abnormal heart rhythm. QT prolongation happens when the electrical signal to the lower chambers of your heart (ventricles) takes too long (prolonged), causing a period of time where these chambers don’t know what to do. During this time, the lower chambers can beat too fast and out of control while waiting for the correct signal.
Torsades de pointes (TdP) happens when the lower chambers start to beat out of control or dangerously fast. This stops your heart from being able to pump enough blood to your body and brain, which can cause fainting or seizures. If not treated right away, TdP can cause your heart to stop beating correctly and can make your heart stop. Call 911 right away if you feel abnormal heartbeats, if your heart is beating fast, or if you feel dizzy or faint.
Allergic Reactions
Some people may have an allergic reaction to this medication. Signs of an allergic reaction are:
- Shortness of breath or trouble breathing.
- Chest pain.
- Rash.
- Itching.
- Flushing (reddening of the skin, often on the face, neck, or chest).
- A drop in blood pressure (you may feel lightheaded, dizzy, or weak).
If you have any of these signs while you are getting an infusion, tell your provider right away. The infusion will be slowed down or stopped. Depending on your reaction, you may still be able to get the medication if you are given medicine to prevent a reaction or if the medication is given at a slower rate.