mirtazapine

Mirtazapine is an antidepressant. It affects chemicals in the brain that may become unbalanced and cause depression.

Mirtazapine is used to treat major depressive disorder.

Mirtazapine may also be used for purposes not listed in this medication guide.

Important information

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. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

Some young 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.

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.

Do not give this medicine to anyone younger than 18 years old without the advice of a doctor. mirtazapine 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.

Before taking this medicine

You should not take this medicine if you are allergic to mirtazapine, or 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. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

To make sure mirtazapine is safe for you, tell your doctor if you have:

• liver or kidney disease;

• narrow-angle glaucoma;

• bipolar disorder (manic depression);

• seizures or epilepsy;

• low blood pressure or dizzy spells;

• high cholesterol or triglycerides;

• heart disease, including angina (chest pain);

• a history of heart attack or stroke; or

• a history of drug abuse or suicidal thoughts.

Some young 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.

FDA pregnancy category C. It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

See also: Pregnancy and breastfeeding warnings (in more detail)

It is not known whether mirtazapine passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

The orally disintegrating tablet may contain phenylalanine. Talk to your doctor before using this form of mirtazapine if you have phenylketonuria (PKU).

How should I take mirtazapine?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Mirtazapine is usually taken once a day at bedtime. Follow your doctor"s instructions.

Take the regular tablet form of mirtazapine with water.

To take the orally disintegrating tablet (Remeron SolTab):

• Keep the tablet in its blister pack until you are ready to take it. Open the package and peel back the foil. Do not push a tablet through the foil or you may damage the tablet.

• Use dry hands to remove the tablet and place it in your mouth.

• Do not swallow the tablet whole. Allow it to dissolve in your mouth without chewing. If desired, you may drink liquid to help swallow the dissolved tablet.

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.

Do not stop using mirtazapine suddenly, or you could have unpleasant withdrawal symptoms. Ask your doctor how to safely stop using this medicine.

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

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

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 should I avoid while taking mirtazapine?

Avoid drinking alcohol. It may 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.

Mirtazapine side effects

Get emergency medical help if you have any of these signs of an allergic reaction to mirtazapine: skin rash or hives; difficult breathing; swelling of your face, lips, tongue, or throat.

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;

• changes in weight or appetite;

• sudden weakness or ill feeling, fever, chills, sore throat, mouth sores, red or swollen gums, trouble swallowing;

• rash, blisters, oozing, or severe pain in the palms of your hands or the soles of your feet;

• high levels of serotonin in the body - agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting;

• low levels of sodium in the body - headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady; or

• severe nervous system reaction - very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.

Common mirtazapine side effects include:

• drowsiness, dizziness;

• strange dreams;

• vision changes;

• dry mouth;

• constipation;

• 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.

See also: Side effects (in more detail)

Mirtazapine dosing information

Usual Adult Dose for Depression:

Initial dose: 15 mg orally once a day at bedtime.
Maintenance dose: 15 to 45 mg per day.

What other drugs will affect mirtazapine?

Taking this medicine with other drugs that make you sleepy can worsen this effect. Ask your doctor before taking mirtazapine with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Tell your doctor about all medicines you use, and those you start or stop using during your treatment with mirtazapine, especially:

• cimetidine (Tagamet);

• diazepam (Valium);

• ketoconazole;

• St. John"s wort;

• tramadol;

• tryptophan (sometimes called L-tryptophan);

• medicine to treat mood disorders, thought disorders, or mental illness - such as lithium, other antidepressants, or antipsychotics;

• migraine headache medicine - sumatriptan, zolmitriptan, and others; or

• seizure medicine - carbamazepine, phenytoin.

Other drugs may interact with mirtazapine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.