See also Warning section.

Before taking amitriptyline with perphenazine, tell your doctor or pharmacist if you are allergic to it; or to other tricyclic antidepressants (such as nortriptyline); or to other phenothiazines (such as chlorpromazine, fluphenazine); 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, decreased bone marrow function, breathing problems (such as asthma, emphysema), liver problems, low blood pressure, recent heart attack, breast cancer, 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 bipolar disorder, alcohol/substance abuse, family history of suicide, seizures, diabetes, conditions that may increase your risk of seizures (such as head injury, drug/alcohol withdrawal), a certain severe reaction to other medications (neuroleptic malignant syndrome), a certain adrenal gland tumor (pheochromocytoma), restless legs syndrome, Parkinson's disease.

Perphenazine/amitriptyline 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 perphenazine/amitriptyline, 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, vomiting, or eating disorders (such as bulimia). Talk to your doctor about using perphenazine/amitriptyline 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. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having any surgery, procedure, or imaging (such as X-ray, CT-scan), tell your doctor or dentist about this medication and 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.

Caution is advised during hot weather because the perphenazine in this product can reduce sweating, increasing your risk for a severe reaction to too much heat (heatstroke). Drink plenty of fluids. Avoid strenuous exercise in hot weather. If you become overheated, promptly seek cooler shelter and/or stop exercising. Get medical help right away if your body temperature is above normal or if you have mental/mood changes, headache, or dizziness.

Avoid exposure to certain chemicals used in gardening (organic phosphate insecticides). Get medical help right away if you are exposed to garden chemicals and have an unusual headache, heavy sweating, or difficulty breathing.

If you have diabetes, this drug may increase 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.

Children may be more sensitive to the side effects of this drug, especially uncontrolled movements.

Older adults may be more sensitive to the side effects of this drug, especially dizziness, lightheadedness, drowsiness, confusion, bleeding, constipation, difficulty urinating, uncontrolled movements, and QT prolongation (see above). Dizziness, lightheadedness, drowsiness, and confusion can increase the risk of falling.

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 symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice any of these symptoms in your newborn especially during their first month, tell the doctor right away.

Since untreated mental/mood problems (such as depression, schizophrenia) 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 medication passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.