Side Effects of the Antidepressant Remeron

How Remeron Works and Common and Serious Side Effects

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Remeron — generic name mirtazapine — is approved by the FDA to treat major depressive disorder. The benefit of Remeron as an anti-depressant has been shown in the elderly, people who have not responded to selective serotonin reuptake inhibitors, or SSRIs, and in those with symptoms of anxiety or insomnia

If you are taking Remeron, it's important to be aware of the several potential side effects.

How Does Remeron Work?

Remeron treats depression by increasing the brain levels of serotonin and norepinephrine, two chemicals linked to mood.


Remeron also blocks histamine, similar to Benadryl. This anti-histamine effect is what causes many of Remeron's classic side effects, like sedation, dry mouth, and weight gain. 

What are the Potential Common Side Effects of Remeron?

It's important to be aware of the potential side effects of Remeron, so you can contact your doctor if bothersome or persistent

Common side effects include:

What are the Potential Serious Side Effects of Remeron?

Remeron may increase suicidal thoughts or behavior. See your doctor right away if your mood and/or behavior is changing or call 911 if an emergency. Remeron can also induce manic episodes, characterized by racing thoughts, agitation, and lack of sleep. This is why caution is used when giving Remeron to a person with bipolar disorder. 

Another serious side effect is that Remeron can decrease infection-fighting cells in your body.

This can make you more prone to getting sick.

Other possible serious side effects include:

  • Serotonin syndrome
  • Vision problems
  • Seizures
  • Low sodium in the blood
  • Rare skin reactions, like Stevens-Johnson syndrome
  • Severe allergic reaction, which may be characterized by difficulty breathing and swelling of the face, tongue, eyes, and mouth
  • Increased cholesterol and triglyceride levels

It's important to note that Remeron is classic for causing sleepiness — so your doctor will likely recommend you take it at bedtime.

What Should I Talk to my Doctor About if I'm Taking Remeron?

Be sure to tell your doctor all the medications you are taking, as they may interact with Remeron and even increase the effects of Remeron. Also, discuss issues like driving and drinking alcohol with your doctor, as these may be concerns while taking Remeron. 


It's important to note that this list is not all-inclusive or meant to replace the information provided by your personal doctor. If you have any worries or concerns when starting or taking Remeron, please speak with your physician right away. 

Also, it's not a good idea to stop taking Remeron or change the dosage without first consulting with your healthcare provider. Stopping Remeron suddenly may cause some undesirable side effects. It's best to do it safely and while being monitored. 


Bhanji NH, Margolese HC, Saint-Laurent M & Chouinard G. Dysphoric mana induced by high-dose mirtazapine: a case for 'norepinephrine syndrome'? Int Clin Psychopharmacol. 2002 Nov;17(6):319-22.

Croom KF, Perry CM & Plosker GL. Mirtazapine: a review of its use in major depression and other psychiatric disorders. CNS Drugs. 2009;23(5):427-52. 

FDA and Manufacturer. Medication Guide: Remeron (Mirtazapine). Retrieved November 12th 2015. 

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