This medication is used to treat certain mental/mood disorders (such as schizophrenia, manic phase of bipolar disorder, schizoaffective disorder). Perphenazine belongs to a class of drugs known as antipsychotics. It works by helping to restore the balance of certain natural substances in the brain.

Take this medication by mouth with or without food as directed by your doctor, usually 1 to 3 times a day.

The dosage is based on your medical condition and response to treatment. Your doctor may direct you to take a low dose at first, gradually increasing the dose to lower the chance of side effects (such as muscle spasms). Follow your doctor's directions carefully.

Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day.

Although you may notice some medication effects soon after starting, it may take as much as 4 to 6 weeks of regular use to see the full benefit. Do not stop taking this medication without consulting your doctor. Your condition may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased.

Tell your doctor if your condition does not get better or if it gets worse.

Drowsiness, constipation, dry mouth, dizziness, lightheadedness, blurred vision, tiredness, or unexplained weight gain may occur. If any of these effects last or get worse, notify your doctor or pharmacist promptly.

Dizziness and lightheadedness can increase the risk of falling. Get up slowly when rising from a sitting or lying position.

Tell your doctor right away if any of these side effects occur: muscle spasm/stiffness, shaking (tremor), restlessness, mask-like expression of the face, drooling/trouble swallowing, or shuffling walk. Your doctor may prescribe another medication to decrease these side effects.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication may cause a condition known as tardive dyskinesia. In some cases, this condition may be permanent. Tell your doctor right away if you develop any involuntary/repetitive muscle movements such as lip smacking/puckering, tongue thrusting, chewing, or finger/toe movements.

In rare cases, perphenazine may increase your level of a certain chemical made by the body (prolactin). For females, this increase in prolactin may result in unwanted breast milk, missed/stopped periods, or difficulty becoming pregnant. For males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor right away.

Tell your doctor right away if you have any serious side effects, including:

• nausea that doesn't stop
• difficulty urinating
• easy bruising/bleeding
• slow heartbeat
• signs of infection (such as sore throat)
• severe muscle spasm/cramping (such as twisting neck, arching back, eyes rolling up)
• seizures
• stomach/abdominal pain
• yellowing eyes/skin

Get medical help right away if you have any very serious side effects, including:

• fast/irregular heartbeat
• severe dizziness
• fainting

This medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms:

• fever
• muscle stiffness/pain/tenderness/weakness
• severe tiredness
• severe confusion
• sweating
• fast/irregular heartbeat
• dark urine
• signs of kidney problems (such as change in the amount of urine)

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking perphenazine, tell your doctor or pharmacist if you are allergic to it, 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:

• decreased bone marrow function
• serious head injury
• liver problems
• nervous system problem (such as drug/alcohol overdose)
• Parkinson's disease
• history of alcohol/substance abuse
• low blood pressure
• breathing problems (such as asthma, emphysema)
• breast cancer
• fast/irregular heartbeat
• heart valve problems
• a certain adrenal gland tumor (pheochromocytoma)
• restless legs syndrome
• seizure disorder
• a certain severe reaction to other medications (neuroleptic malignant syndrome)
• difficulty urinating (such as due to prostate problems)

Perphenazine 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, 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 perphenazine 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).

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.

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

Caution is advised during hot weather because perphenazine 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.

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, muscle spasm/stiffness, tardive dyskinesia, and QT prolongation (see above). Drowsiness, dizziness, and lightheadedness 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 schizophrenia, bipolar disorder, schizoaffective 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.

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

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: slow/shallow breathing, inability to wake up (coma).

Do not share this medication with others.

Lab and/or medical tests (such as complete blood count, liver function, eye exams) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.