Mirtazapine

Generic name: mirtazapine (mir TAZ a peen)
Brand name: Remeron, Remeron SolTab
Drug class: Tetracyclic antidepressants

Mirtazapine is an antidepressant. The way this medication works is still not fully understood. It is thought to positively affect communication between nerve cells in the central nervous system and/or restore chemical balance in the brain.

Mirtazapine is used to treat major depressive disorder in adults.

It is not known if mirtazapine is safe and effective for use to treat MDD in children.

Warnings

You should not take mirtazapine if you are also taking tryptophan (sometimes called L-tryptophan).

Do not use mirtazapine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, tranylcypromine and others.

Some people have thoughts about suicide when first taking an antidepressant. Your doctor will need to check your progress at regular visits while you are using mirtazapine. Your family or other caregivers should also be alert to changes in your mood or symptoms.

Do not give this medicine to anyone younger than 18 years old without the advice of a doctor. This medicine is not approved for use in children.

It may take up to several weeks before your symptoms improve. Keep using the medication as directed and tell your doctor if your symptoms do not improve after 4 weeks of treatment.

Drinking alcohol can increase certain side effects of mirtazapine.

Mirtazapine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Do not stop taking this medicine abruptly. Talk to your doctor before stopping this medicine.

Before taking this medicine

You should not take this medicine if you are allergic to mirtazapine.

Do not use mirtazapine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, tranylcypromine, and others.

To make sure this medicine is safe for you, tell your doctor if you have ever had:

  • low white blood cell counts;
  • glaucoma;
  • liver or kidney disease;
  • low sodium levels in your blood;
  • a seizure;
  • depression, suicidal thoughts or actions;
  • bipolar disorder (manic depression) in you or a family member;
  • heart problems or stroke;
  • high cholesterol or triglycerides;
  • long QT syndrome (in you or a family member); or
  • low blood pressure.

Be sure your doctor knows if you also take stimulant medicine, opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson's disease, migraine headaches, serious infections, or prevention of nausea and vomiting. These medicines may interact with mirtazapine and cause a serious condition called serotonin syndrome.

Some young people have thoughts about suicide when first taking an antidepressant. Your doctor should check your progress at regular visits. Your family or other caregivers should also be alert to changes in your mood or symptoms.

Tell your doctor if you are pregnant or breastfeeding.

The orally disintegrating tablet may contain phenylalanine and could be harmful if you have phenylketonuria (PKU).

Mirtazapine is not approved for use by anyone younger than 18 years old.

How should I take mirtazapine?

Take mirtazapine exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

Take the medicine at the same time each day, usually at bedtime.

Take the regular tablet form of mirtazapine with water.

You may take mirtazapine with or without food.

Remove an orally disintegrating tablet from the package only when you are ready to take the medicine. Place the tablet on your tongue and allow it to dissolve, without chewing. Swallow several times as the tablet dissolves.

It may take a few weeks for your symptoms to improve. Keep using the medication as directed and tell your doctor if your symptoms do not improve after 4 weeks of treatment.

Do not stop using mirtazapine suddenly, or you could have unpleasant symptoms (such as dizziness, vomiting, agitation, sweating, confusion, numbness, tingling, or electric shock feelings). Ask your doctor how to safely stop using this medicine.

Store at room temperature away from moisture, heat, and light.

Dosing information

Usual Adult Dose for Depression:

Initial dose: 15 mg orally once a day at bedtime
Maintenance dose: 15 to 45 mg orally once a day
Maximum dose: 45 mg/day

Comments:
-May increase the dose every 1 to 2 weeks to a maximum 45 mg/day according to patient response.
-Patients should be periodically reassessed to determine the need for continued use of this drug.

Use: Treatment of major depressive disorder

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include confusion, memory problems, drowsiness, and fast heart rate.

What to avoid

Drinking alcohol with mirtazapine can cause side effects.

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.

Mirtazapine side effects

Get emergency medical help if you have signs of an allergic reaction to mirtazapine (hives, joint pain, fever, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.

Call your doctor at once if you have:

  • racing thoughts, decreased need for sleep, unusual risk-taking behavior, feelings of extreme happiness or sadness, being more talkative than usual;
  • blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • a light-headed feeling, like you might pass out;
  • severe rash, blisters, or swelling on the palms of your hands or the soles of your feet;
  • a seizure;
  • low white blood cell counts - fever, chills, sore throat, cough, sores in your mouth or nose, flu-like symptoms, trouble breathing; or
  • low sodium level - headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady.

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Common mirtazapine side effects include:

  • drowsiness, dizziness;
  • increased appetite; or
  • weight gain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect mirtazapine?

Using mirtazapine with other drugs that make you drowsy can worsen this effect. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Tell your doctor about all your current medicines. Many drugs can affect mirtazapine, especially:

  • cimetidine;
  • diazepam;
  • St. John's wort;
  • tramadol;
  • tryptophan (sometimes called L-tryptophan);
  • an antibiotic - clarithromycin, rifampin, rifampicin, telithromycin;
  • antifungal medicine - itraconazole, ketoconazole;
  • antiviral medicine to treat HIV/AIDS - indinavir, nelfinavir, ritonavir, saquinavir;
  • medicine to treat mood disorders, thought disorders, or mental illness - such as lithium, other antidepressants, or antipsychotics;
  • migraine headache medicine - sumatriptan, rizatriptan, Imitrex, Maxzalt, and others; or
  • seizure medicine - carbamazepine, phenytoin.

This list is not complete and many Other drugs may interact with mirtazapine. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.