Generic name: perphenazine [ per-FEN-a-zeen ]
Brand name: Trilafon
Dosage form: oral tablet (16 mg; 2 mg; 4 mg; 8 mg)
Drug classes: Phenothiazine antiemetics, Phenothiazine antipsychotics

Medically reviewed by Drugs.com on Aug 3, 2023. Written by Cerner Multum.

What is perphenazine?

Perphenazine is a phenothiazine (FEEN-oh-THYE-a-zeen) anti-psychotic medicine.

Perphenazine is used to treat psychotic disorders such as schizophrenia. It is also used to control severe nausea and vomiting.

Perphenazine may also be used for purposes not listed in this medication guide.

Perphenazine side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

High doses or long-term use of perphenazine can cause a serious movement disorder that may not be reversible. The longer you use perphenazine, the more likely you are to develop this disorder, especially if you are a woman or an older adult.

Perphenazine may cause serious side effects. Call your doctor at once if you have:

• uncontrolled muscle movements in your arms or legs, or your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);

• worsening symptoms of schizophrenia;

• confusion, paranoia, feeling restless or excited;

• seizure (convulsions);

• a light-headed feeling, like you might pass out;

• jaundice (yellowing of your skin or eyes);

• little or no urinating;

• slow heart rate, weak pulse, weak or shallow breathing;

• low white blood cell counts--fever, chills, mouth sores, skin sores, sore throat, cough, trouble breathing, feeling light-headed; or

• severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, fast or uneven heartbeats.

Side effects such as dry mouth, constipation, tremors, and drowsiness may be more likely in older adults.

Common side effects of perphenazine may include:

• mild dizziness or drowsiness;

• blurred vision, headache;

• sleep problems (insomnia), strange dreams;

• loss of appetite, vomiting, diarrhea, constipation;

• increased sweating or urination;

• dry mouth or stuffy nose;

• breast swelling or discharge; or

• mild itching or skin rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

You should not use perphenazine if you have liver disease, brain damage, bone marrow depression, a blood cell disorder, or if you are also using large amounts of alcohol or medicines that make you sleepy.

Perphenazine is not approved for use in older adults with dementia-related psychosis.

Call your doctor at once if you have twitching or uncontrollable movements of your eyes, lips, tongue, face, arms, or legs. These could be early signs of dangerous side effects.

Before taking this medicine

You should not use perphenazine if you are allergic to any phenothiazine (such as perphenazine, chlorpromazine, prochlorperazine, promethazine, o thioridazine), or if you have:

• liver disease;

• brain damage;

• bone marrow depression;

• a blood cell disorder (such as low platelets or low red or white blood cell counts); or

• if you are also using large amounts of alcohol or medicines that make you sleepy.

Perphenazine may increase the risk of death in older adults with dementia-related psychosis and is not approved for this use.

Tell your doctor if you have ever had:

• severe or untreated depression;

• heart disease or high blood pressure;

• kidney disease;

• severe asthma, emphysema, or other breathing problem;

• seizures;

• Parkinson's disease;

• breast cancer;

• adrenal gland tumor (pheochromocytoma);

• enlarged prostate or urination problems;

• low levels of calcium in your blood (hypocalcemia);

• glaucoma; or

• a serious side effect while using perphenazine or another phenothiazine.

Tell your doctor if you will be exposed to extreme heat or cold, or to insecticide poisons while you are taking perphenazine.

Tell your doctor if you are pregnant or you become pregnant. Taking antipsychotic medicine in the last 3 months of pregnancy may cause breathing problems, feeding problems, or withdrawal symptoms in the newborn.

It may not be safe to breastfeed while using this medicine. Ask your doctor about any risk.

How should I take perphenazine?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You will need frequent medical tests.

If you need surgery, tell your surgeon you currently use this medicine.

Do not stop using perphenazine suddenly, or you could have unpleasant symptoms such as nausea, vomiting, dizziness, or tremors. Ask your doctor how to safely stop using this medicine.

Store at room temperature away from moisture, heat, and light.

Perphenazine dosing information

Usual Adult Dose for Psychosis:

Moderately disturbed, nonhospitalized patients:
-Recommended dose: 4 to 8 mg orally 3 times a day, with a dose reduction to the minimum effective dose as soon as possible
-Maximum dose: 24 mg/day

Hospitalized patients:
-Recommended dose: 8 to 16 mg orally 2 to 4 times a day
-Maximum dose: 64 mg/day

Comment:
-Nonhospitalized patients should be limited to a daily dose of 24 mg; maximum doses of 64 mg should be used in hospitalized patients.

Use: Treatment of schizophrenia

Usual Adult Dose for Nausea/Vomiting:

Recommended dose: 8 to 16 mg orally, in divided doses
Maximum dose: 24 mg/day, in divided doses

Comment:
-The dose should be reduced as early as possible.

Use: Severe nausea and vomiting

Usual Pediatric Dose for Psychosis:

12 years and older:
Moderately disturbed, nonhospitalized patients:
-Recommended dose: 4 to 8 mg orally 3 times a day, with a dose reduction to the minimum effective dose as soon as possible
-Maximum dose: 24 mg/day

Hospitalized patients:
-Recommended dose: 8 to 16 mg orally 2 to 4 times a day
-Maximum dose: 64 mg/day

Comments:
-Nonhospitalized patients should be limited to a daily dose of 24 mg; maximum doses of 64 mg should be used in hospitalized patients.

Use: Treatment of schizophrenia

Usual Pediatric Dose for Nausea/Vomiting:

12 years and older:
-Recommended dose: 8 to 16 mg orally, in divided doses
-Maximum dose: 24 mg/day, in divided doses

Comment:
-The dose should be reduced as early as possible.

Use: Severe nausea and vomiting

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of perphenazine can be fatal.

What should I avoid while taking perphenazine?

Avoid driving or hazardous activity until you know how perphenazine will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Avoid drinking alcohol. It can increase some of the side effects of perphenazine.

Avoid exposure to sunlight or tanning beds. Perphenazine can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

What other drugs will affect perphenazine?

Taking perphenazine with other drugs that make you sleepy or slow your breathing can cause dangerous or life-threatening side effects. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Many drugs can affect perphenazine. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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