See also Warning section.

Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or to other tricyclic antidepressants (such as imipramine, amitriptyline); 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: breathing problems (such as asthma, chronic bronchitis), personal or family history of glaucoma (angle-closure type), diabetes, eating disorders (such as bulimia), heart problems (such as arrhythmias, coronary artery disease, heart attack), liver problems, kidney problems, personal or family history of other mental/mood conditions (such as bipolar disorder, schizophrenia), seizures, overactive thyroid (hyperthyroidism), trouble urinating (such as due to enlarged prostate), any condition that may increase your risk of seizures (including alcohol/sedative dependency, use of electroconvulsive therapy, brain injury/disease such as stroke), certain types of tumors (such as pheochromocytoma, neuroblastoma).

Desipramine 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 desipramine, 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 desipramine safely.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

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

This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.

If you have diabetes, this drug may make it harder to control your blood sugar. Check your blood sugar regularly as directed and share the results with your doctor. Tell your doctor right away if you have symptoms such as increased thirst/urination. Your doctor may need to adjust your diabetes medication, exercise program, or diet.

Older adults may be more sensitive to the side effects of this drug, especially dizziness (more likely when standing up), drowsiness, constipation, trouble urinating, mental/mood changes (such as confusion, agitation) and heart effects such as QT prolongation (see above). Dizziness, drowsiness, and confusion can increase the risk of falling.

During pregnancy, this medication should be used only when clearly needed. Infants born to mothers who have taken similar medications during pregnancy may have symptoms such as trouble urinating, prolonged sleepiness, shaking, and seizures. Discuss the risks and benefits with your doctor.

Since untreated mental/mood problems (such as depression, panic disorder) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss with your doctor the benefits and risks of using this medication during pregnancy.

This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.