Mirtazapine Side Effects

by on July 21, 2012


The most commonly reported side effects of Mirtazapine (Remeron, Soltab) are constipation, dry mouth, dizziness, drowsiness, weight gain, and increased appetite.  These side effects usually diminish after the body has had time to adjust to the medication but a doctor should be notified if they persist or become bothersome.

Common Mirtazapine Side Effects

The most commonly reported Mirtazapine side effects include the following:

  • Constipation
  • Dry mouth
  • Dizziness
  • Drowsiness
  • Weight gain
  • Increased appetite

Other side effects that are less common include the following:

  • Weakness
  • Vomiting
  • Trembling or shaking
  • Muscle pain
  • Nausea
  • Sense of movement within self and surroundings
  • Increased urination
  • Low blood pressure
  • Increased thirst
  • Increased sensitivity to touch
  • Back pain
  • Abnormal dreams
  • Stomach pain
  • Dizziness or fainting when getting up too quickly

The side effects listed above usually do not require medical attention as they will commonly diminish when your body adjusts to the medication. Your doctor may also be able to advise you of ways to reduce or prevent these common side effects from occurring. However, if any persist or become bothersome you should notify your doctor to discuss alternative solutions.

Serious Mirtazapine Side Effects

A severe allergic reaction can occur with mirtazapine medications. If you experience any of the following symptoms indicating an allergic response, seek emergency medical help right away.

  • Hives
  • Difficulty breathing
  • Swelling of the lips, face, throat, or tongue

Many other Mirtazapine side effects can occur that do not indicate an allergic reaction but are still very serious. You should notify your doctor right away if you experience any of the following side effects:

  • Increase or decrease in movement
  • Shortness of breath
  • Swelling
  • Skin rash
  • Mood or mental changes- intense emotions, abnormal thinking, or feelings of hopelessness
  • Confusion
  • Convulsions
  • Decreased sexual ability
  • Mouth sores
  • Sore throat
  • Chills
  •  High fever
  • Menstrual pain
  • Change in menstrual cycle
  • Hallucinations
  • Feelings of depersonalization
  • Symptoms of mania such as reckless behavior or large amounts of energy.
  • Loss of coordination
  • Increased heart rate
  • Tremors
  • Nausea
  • Stiff or rigid muscles
  • Diarrhea
  • Sweating
  • Overactive reflexes

Drowsiness Inducing Medications

Mirtazapine medications can cause drowsiness; this side effect may be greatly exacerbated by taking medications that can cause drowsiness while taking mirtazapine. You should talk to your doctor before taking any of the following medications; antihistamines, sleeping medications, narcotic pain medications, tranquilizers, muscle relaxants, anesthetics, and allergy or cold medications. It is also important that you do not drive or operate machinery until you are familiar with the way your body responds to Remeron. You should always use caution before performing any task or action that requires you to be alert and focused while taking mirtazapine medications.

White Blood Cells

Mirtazapine medications such as Remeron and Soltab can temporarily lower your white blood cell count making you more susceptible to infections. If possible, while taking this medication try to avoid people who have infections. Contact your doctor right away if you think you may be getting an infection, have a sore throat, sores in your mouth, fever, chills, pain or difficulty urinating, and lower back or side pain.

Pregnancy and Elderly Individuals

Women who are pregnant or may become pregnant should talk to a doctor before taking a mirtazapine medication in order to weigh the potential benefits of the drug against possible risks. This medication has been placed in category C by the FDA, which means it is unknown how this drug may affect an unborn child. Women who are breastfeeding should also discuss this medication with a doctor; the drug can pass through breast milk and the potential effects on a newborn are not known at this time.

Elderly individuals are more likely to experience drowsiness, age related kidney problems, and confusion when taking mirtazapine medications. You should discuss potential risks with your doctor to ensure you are on the most effective dosage with the least risk; it is also important to use caution when taking this drug to avoid accidents. All bothersome or worrisome side effects should be reported to your doctor right away.

Additionally, the following medical conditions may require special tests or dosage adjustments; dehydration, blood vessel disease, angina, heart disease, history of heart attack or stroke, hypovolemia, hypotension, history or stroke, history of seizures, history of mania, hypercholesterolemia, liver disease, kidney disease, and Phenylketonuria.

The tetracyclic medication mirtazapine is used in the treatment of depression. Certain medical conditions should be reported to your doctor before taking this medication as they may pose significant health risks. Be aware of any changes to your mood or behavior while taking this medication and report any serious or bothersome side effect to your health care provider right away.