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Mirtazapine Side Effects: What Adverse Reactions Does Remeron Cause?

Last Updated: November 24, 2021

Authored by Sharon Levy, MD, MPH

Reviewed by Michael Espelin APRN

Remeron, under the generic name Mirtazapine, is a medication that is used for the treatment of depression. Similar to other drugs, Remeron side effects may occur at the initial stages of drug use or overtime use. Additionally, these Mirtazapine side effects may be mild in some patients and go away after a while, so a question often arises: does remeron cause weight gain? However, others may experience more severe adverse reactions. According to the study of medical doctors from Germany, 9 out of 10 patients who use this medication experience Remeron side effects. Therefore, with these statistics, patients taking medication must understand what Mirtazapine may do to their health.

What Are The Common Mirtazapine Side Effects?

Mirtazapine side effects may vary from one patient to another depending on age and duration of use among several other factors, including Remeron interactions. For example, the interaction of alcohol with this medication. Patients are advised not to mix Mirtazapine with alcohol as this may increase the nervous system adverse reactions of the drug such as drowsiness and dizziness.

Physical Side Effects Of Remeron

The drug Remeron treats depression and acts on the brain but this does not mean that it only causes emotional or psychological symptoms. Instead, it also causes physical changes such as weight gain.

Other Common Physical Adverse Reactions Can Be Seen In The Information Below:

  • Xerostomia or dry mouth
  • Constipation
  • Increased appetite
  • Sedation
  • Drowsiness
  • Tremors

According to a study of healthcare professionals, drowsiness is the most common physical adverse reaction to Remeron with a prevalence rate of 54%. For this reason, patients using this medication are advised not to operate any machinery to avoid accidents.

Cardiovascular System

Aside from the physical adverse reactions listed above, a Mirtazapine tablet also causes physical cardiovascular changes. According to a study of medical doctors from the USA, this drug can increase the cholesterol levels of patients, and this has a prevalence rate of 15%.

In another study by medical doctors from Slovenia, it was found out that this drug can cause thrombocytopenia. Further, it was reported that patients who experience this lowering of blood platelets are due to their sensitivity to the drug.

Lastly, according to the information given by the healthcare professionals from New York, Mirtazapine is also associated with hypertriglyceridemia. Because of this, professionals are advised to always check the baseline triglyceride levels of patients and monitor them regularly while under the treatment of Remeron.

Gastrointestinal System

A study conducted by medical doctors from Germany states that this drug can cause acute pancreatitis (the inflammation of the pancreas). Because this is just an acute condition, it may possibly go unrecognized. However, take note that untreated pancreatitis may lead to a chronic one and this is dangerous. In another study by medical professionals from Los Angeles, Mirtazapine is also associated with liver disease. For these reasons, it is advised to always monitor the pancreatic and liver enzyme levels of the patient especially when the dose has to be increased.

A woman experiences Remeron side effects.

Psychological Side Effects Of Remeron

According to the FDA, the most common but dangerous adverse reactions of taking a Remeron tablet is increased risk of suicidal thoughts and this occurs when the dose of the drug is increased, or patients have Remeron addiction and abuse issues. Furthermore, patients who are below 24 years are more prone to this adverse reaction.

Other Psychological Adverse Reactions of This Drug Include the Following:

  • Confusion
  • Problem in concentrating
  • Memory problems
  • Unsteady feelings

Although these symptoms are considered common, it is still important to know about them. In case a patient is experiencing any of the symptoms listed above, it is advised to seek immediate medical care in order to avoid other dangerous health events.

Rare Remeron Side Effects

Aside from the common ones, using a Remeron tablet may also pose rare adverse reactions. According to the study of medical doctors from Pennsylvania, one rare adverse effect of the use of a Remeron tablet is a change in the menstrual period cycle of a woman along with menstrual pain.

Another rare adverse reaction to the use of this medication is the condition called serotonin syndrome. According to the study of a medical doctor from Ohio, this serotonin syndrome is life-threatening, and this occurs when too much of this drug is taken. Additionally, being at risk of having this condition can be increased when this drug is combined with a selective serotonin reuptake inhibitor (SSRI) medication.

Remeron Side Effects In Elderly

According to the FDA, hyponatremia, or low levels of sodium, is one of the Remeron side effects in elderly. Therefore, other drugs that may cause lowering of sodium levels must never be combined with this drug.

Remeron Side Effects in Elderly Patients May Also Be Directly Linked to the Following:

  • Decreased renal functions
  • A slower metabolism
  • Excretion of medication

Since elderly patients are more vulnerable to any drugs, care should be taken when prescribing a correct dosage. In fact, there aren’t any specific Mirtazapine side effects among geriatric patients as a result of their age. The point is that the common and rare Remeron side effects can happen with a higher likelihood. According to the Nebraska Geriatric Education Centre, treatment of depression among the elderly population should be based upon concurrent depressive symptoms. However, elderly patients are more likely to have unusual drowsiness related directly to Mirtazapine side effects. Age-related kidney problems are also more frequent in elderly patients.

Does Remeron Cause Dementia?

Research by the United States National Library of Medicine proposes that some antidepressant drugs are associated with an increased risk of dementia. Similarly, a Nationwide Cohort Study in Taiwan found that 3.08% of a 29,095 sample study population prescribed to the drug had experienced dementia as one of the Remeron adverse reactions. That is why this drug is associated with the development of dementia, especially in elderly patients.

Remeron Sexual Side Effects

According to Harvard Health Publishing, between 35% and 50% of people diagnosed with major depression may experience some kind of sexual dysfunction. In terms of Mirtazapine, according to medical doctors from Korea, around 24.4% of patients being treated with this medication experience Remeron sexual side effects such as the following:

  • Decreased libido
  • Delayed orgasm
  • Erectile dysfunction

Take note that this percentage is actually lower compared to other antidepressant drugs. Moreover, for patients who are looking for some ways to deal with these Remeron sexual side effects,  possible solutions include:

  • Scheduling sex to a time where the effects of the drug are the least bothersome
  • Taking a lower dose of medication after the approval of a doctor
  • Waiting until the body is able to tolerate the adverse reaction to the drug

In case the sexual side effects of Mirtazapine persist or become more discomforting, it is advised to seek medical care in order to properly address the issues. Do not stop taking the medication without the approval of a doctor as this may lead to Mirtazapine withdrawal symptoms.

Can Mirtazapine Cause Restless Leg Syndrome?

The joint use of Mirtazapine with Tramadol or other dopamine-blocking agents can increase the risk of restless leg syndrome as an adverse reaction to Remeron medication. Therefore, a doctor is advised to watch carefully for the development of RLS when the drug is administered to patients who are taking any dopamine-blocking agents.

When Do The Side Effects Of Mirtazapine Go Away?

Some people take Remeron without any adverse reactions or with only a few mild adverse reactions. According to the United Kingdom National Health Service, most of the common Remeron side effects go away after the first weeks of being on the medication.

In terms of the rare side effects of Mirtazapine such as serotonin syndrome, the mild form of this condition would take 3 days for it to go away after treating it. However, for severe and untreated cases, this could cause coma or death. If any of the rare side effects of Mirtazapine prolongs, do not decide to stop taking the drug without consulting a doctor.

Mirtazapine Risks: How To Manage Remeron Side Effects

If a patient is experiencing fatigue or drowsiness as a Mirtazapine adverse reaction, they should seek medical assistance from a doctor and suggest taking medicine at a different time of day. An increase in appetite may cause undesirable weight gain. Mirtazapine weight gain can be managed through early intervention and proper dietary regimens. Patients are also advised to drink plenty of water, eat high-fiber foods, and exercise regularly if constipation occurs.

If the patients are unable to manage the health hazards at home, they can refer to rehab for drug addicts. These facilities can also help in case of medication abuse or misuse. The addiction treatment programs here are designed to give patients information and help in a way to meet all the specific needs of patients, as well as ensure a long-standing recovery.

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Published on: November 25th, 2019

Updated on: November 24th, 2021

About Author

Sharon Levy, MD, MPH

After successful graduation from Boston University, MA, Sharon gained a Master’s degree in Public Health. Since then, Sharon devoted herself entirely to the medical niche. Sharon Levy is also a certified addiction recovery coach.

Medically Reviewed by

Michael Espelin APRN

8 years of nursing experience in wide variety of behavioral and addition settings that include adult inpatient and outpatient mental health services with substance use disorders, and geriatric long-term care and hospice care.  He has a particular interest in psychopharmacology, nutritional psychiatry, and alternative treatment options involving particular vitamins, dietary supplements, and administering auricular acupuncture.