Before taking this medication, tell your doctor or pharmacist if you are allergic to it, or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: history or family history of psychiatric disorders (such as bipolar/manic-depressive disorder), history or family history of suicide attempts, liver disease, kidney disease, seizures, high blood cholesterol or triglyceride levels, heart disease (such as recent heart attack, angina), stroke, severe loss of body fluids (dehydration), low blood pressure, personal or family history of glaucoma (angle-closure type).

Mirtazapine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.

The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using mirtazapine, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using mirtazapine safely.

This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Older adults may be more sensitive to the side effects of this drug, especially drowsiness and QT prolongation (see above).

During pregnancy, this medication should be used only when clearly needed. If this medication is used during the last 3 months of pregnancy, rarely your newborn may develop symptoms including feeding or breathing difficulties, seizures, muscle stiffness, jitteriness or constant crying. Report any such symptoms to your doctor promptly. However, since untreated mental/mood disorders (such as depression) can be a serious condition, do not stop taking this medication unless your doctor directs you to do so. If you are planning pregnancy, become pregnant, or think you may be pregnant, discuss with your doctor right away the benefits and risks of using this medication during pregnancy.

This drug passes into breast milk. Consult your doctor before breastfeeding.