See also Warning section.

Before taking doxepin, tell your doctor or pharmacist if you are allergic to it; or to other tricyclic antidepressants (such as nortriptyline); 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: bleeding problems, breathing problems, liver problems, recent heart attack, problems urinating (such as due to enlarged prostate), overactive thyroid (hyperthyroidism), personal or family history of glaucoma (angle-closure type), personal or family history of mental/mood conditions (such as bipolar disorder, psychosis), family history of suicide, seizures, conditions that may increase your risk of seizures (such as other brain disease, alcohol/sedative withdrawal).

Doxepin 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 doxepin, 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 doxepin safely.

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).

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

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 levels. Monitor your blood sugar levels regularly and tell your doctor of the results. 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 dry mouth, dizziness, drowsiness, confusion, difficulty urinating, and QT prolongation (see above).

During pregnancy, this medication should be used only when clearly needed. Babies born to mothers who have used this drug during the last 3 months of pregnancy may rarely develop withdrawal symptoms such as feeding/breathing difficulties, seizures, muscle stiffness, or constant crying. If you notice any of these symptoms in your newborn, tell the doctor promptly.

Since untreated mental/mood problems (such as depression, anxiety) can be a serious condition, do not stop using 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 medication passes into breast milk and may have undesirable effects on a nursing infant. Breastfeeding is not recommended while using this medication. Consult your doctor before breastfeeding.