It is very important that your doctor check your progress at regular visits to see if the medicine is working properly and to decide if you should continue to take it. Blood tests may be needed to check for unwanted effects.
Do not use this medicine if you are also taking a medicine for depression called a MAO inhibitor, such as isocarboxazid, phenelzine, selegiline, tranylcypromine, Eldepryl®, Marplan®, Nardil®, or Parnate® in the past 14 days. Using these medicines together may cause serious unwanted effects.
If you take a certain brand of this medicine (e.g., Remeron®, Remeron Sol Tab®), you should not take any other brands that contain mirtazapine.
For some children, teenagers, and young adults, this medicine can increase thoughts of suicide. Tell your doctor right away if you start to feel more depressed and have thoughts of hurting yourself. Report any unusual thoughts or behaviors that trouble you, especially if they are new or getting worse quickly. Make sure the doctor knows if you have trouble sleeping, get upset easily, have a big increase in energy, or start to act reckless. Also tell the doctor if you have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. Let the doctor know if you or anyone in your family has bipolar disorder (manic-depressive) or has tried to commit suicide.
Using this medicine may cause serotonin syndrome or neuroleptic malignant syndrome (NMS)-like reactions. Check with your doctor right away if you are having agitation, convulsions, difficulty in breathing, fast heartbeat, hallucinations, high fever, high or low blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, unusually pale skin, or tiredness while you are taking this medicine.
This medicine may add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for allergies or colds, sedatives, tranquilizers, or sleeping medicines, prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are taking this medicine.
This medicine can temporarily lower the number of white blood cells in your blood, increasing your chance of getting an infection. If you can, avoid people with infections. Stop using this medicine and check with your doctor right away if you think you are getting an infection or if you have a fever or chills, sore throat, sores in the mouth, lower back or side pain, or painful or difficult urination.
Do not suddenly stop taking this medicine without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping completely. This may help prevent a possible worsening of your condition and reduce the possibility of withdrawal symptoms such as headache, nausea, or a general feeling of discomfort or illness.
This medicine may increase your weight. Your doctor may need to check your weight on a regular basis while you are using this medicine.
Mirtazapine may cause drowsiness, trouble with thinking, or trouble with controlling body movements. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that requires you to be alert, well-coordinated, and able to think well.
Dizziness, lightheadedness, or fainting may occur, especially when you get up suddenly from a lying or sitting position. Getting up slowly may help. If this problem continues or gets worse, check with your doctor.
This medicine may cause dryness of the mouth. For temporary relief, use sugarless gum or candy, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth feels dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (e.g., St. John's wort) or vitamin supplements.