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Name of the generic: perphenazine [per-FEN-a-zeen per-FEN-a-zeen]
Name of brand: Trilafon
Dosage format: oral tablet (16 mg, 2 mg, 4 mg, 8 mg)
Drug classes: phenothiazine antiemetics, phenothiazine antipsychotics

What is Perphenazine?

Perphenazine is a phenothiazine (FEEN-oh-THYE-a-zeen) anti-psychotic medicine. Perphenazine can be used for treating psychotic conditions, such as schizophrenia. It can also be utilized to treat extreme nausea and vomiting. Perphenazine can also be employed for other purposes that are not covered in this guideline.

Side effects of Perphenazine:

See a doctor immediately. If you notice any of the following symptoms that indicate reactions to an allergen, such as hives: difficulty breathing and swelling of your lips, face, and tongue,

Long-term or high-dose use of perphenazine could cause serious movement disorders that might not be reverseable. The longer you take perphenazine, the more likely you are to suffer from this disorder, particularly in the case of women or older people.

Perphenazine could cause serious adverse side effects. Contact your physician immediately if you suffer from:

  • Muscles that are not controlled in your legs or arms or in your facial expressions (chewing lipsmacking, chewing smiles, tongue movements, blinking, or eye movements);
  • The symptoms of schizophrenia are getting worse.
  • Anxiety, confusion, paranoia, feeling nervous or anxious;
  • Seizure (convulsions);
  • A feeling of lightheadedness, as if you're about to pass out.
  • Jaundice (yellowing of your eyes or skin);
  • Very little or no urine;
  • Fast heartbeat low-pulse breath that is shallow or weak;
  • Low white blood cell count low white blood cell counts, fever, chills, and mouth sores. Skin open sores, throat sores, cough, difficulty breathing, feeling lightheaded or
  • Extremely rigid (rigid) muscles with high fever, sweating, and rapid or irregular heartbeats.

Other side effects, such as dry mouth, constipation, tremors, and sleepiness, are more likely for older adults.

Common side effects of perphenazine include:

  • Slight dizziness or drowsiness
  • Fuzzy vision; migraine;
  • Sleep problems (insomnia), strange dreams;
  • Nausea, loss of appetite, diarrhea, constipation;
  • More sweating or urination;
  • Dry nose or mouth;
  • Breast swelling or discharge; or
  • Mild itching, skin itching, or a rash

This isn't a complete list of possible side effects, and other effects may also be present. Contact your doctor for advice regarding medical effects. You can report any side effects to the FDA at 1-800-FDA-1088.


Perphenazine is not recommended when you suffer from an illness of the liver or brain, damage to bones, depression, or a blood cell disorder, or are also taking large quantities of alcohol or drugs that cause you to sleep. Perphenazine isn't permitted for use by older adults suffering from dementia-related psychosis.Consult your doctor immediately in the event of twitching or uncontrollable movements in your lips, eyes, face, tongue, or legs. These could be signs of potentially harmful adverse effects.

Before you start taking this medicine

Perphenazine should not be used when you have an allergy to any of the phenothiazine (such as perphenazine chlorpromazine, prochlorperazine, promethazine, and thioridazine) or if you suffer from:

  • Liver disease;
  • Brain damage;
  • Degeneration of the bone marrow;
  • A condition of the blood cells (such as a low number of platelets or a low white or red count of blood cells) or
  • If you're also taking high amounts of alcohol or other drugs that cause you to feel sleepy,

Perphenazine can raise the chance of dying in elderly patients suffering from psychosis relating to dementia. However, it isn't recommended for use in this manner.

Speak to your doctor if you have ever suffered from:

  • Depressive disorder that is untreated or severe;
  • Heart disease, also known as hypertension,
  • Kidney disease;
  • Extremely severe asthma, emphysema, or any other breathing issue;
  • Seizures;
  • Parkinson's disease;
  • Breast cancer;
  • The adrenal gland (pheochromocytoma);
  • Prostate enlargement or urination issues
  • The calcium levels are low in the blood (hypocalcemia);
  • Glaucoma; or
  • A serious adverse reaction when making use of perphenazine or any other phenothiazine.

Inform your physician if you are going to be exposed to extreme temperatures or colds or to pesticide poisons while taking perphenazine. Inform your doctor if you are pregnant or if you become pregnant. Antipsychotic medication taken during the last three months of pregnancy can result in breathing issues and feeding issues, as well as withdrawal symptoms in newborn babies. It is not recommended to breastfeed while taking this medication. Consult your physician regarding any risks.

How to take Perphenazine?

Follow the directions on the prescription label and review all medication guides and instructions sheets. Your doctor may alter the dosage. Make sure you take the medication exactly as prescribed.

You'll need to take regular medical tests.

If you require surgery, be sure to inform your doctor that you are currently taking this medication.

Do not stop taking perphenazine abruptly, or you could experience uncomfortable symptoms like dizziness, nausea, vomiting, or shaking. Consult your physician about how you can be sure to stop taking this medication.

Keep at room temperature, far from heat, humidity, and light.

Details on dosage

Usual Adult Dose for Psychosis:

Nonhospitalized, moderately disturbed patients:
The recommended dose is 4–8 mg, orally, 3 times per day, with an increase in dose to the dose that is effective when it is feasible.
Maximum dose: 24 mg/day

Hospitalized patients:
The recommended dose is 8 to 16 mg taken orally, up to 3 times per day.
Maximum dose: 64 mg/day

Patients who are not hospitalized should be restricted to daily doses of 24 mg. Maximum dosages of up to 64 mg are recommended to be prescribed to patients in hospitals.

Use: Treatment for schizophrenia

Usual Adult Dose for Nausea or Vomiting:

Recommended dosage 8–16 mg taken orally, divided into doses
Maximum dose: 24 mg/day, in divided doses

The dose should be decreased at the earliest possible time.

Use: severe nausea and vomiting

Usual Pediatric Dose for Psychosis:

12-year-olds and older:
Nonhospitalized, moderately disturbed patients:
The recommended dose is 4 to 8 mg taken orally three times a day, with an increase in dose to the lowest dose when it is feasible.
Maximum dose: 24 mg/day

Hospitalized patients:
Recommended dose of 8 to 16 mg taken orally between 2 and four times a day
Maximum dose: 64 mg/day

Nonhospitalized patients should be restricted to daily doses of 24 mg. Maximum dosages of up to 64 mg are recommended to be prescribed to patients in hospitals.

Treatment for schizophrenia: use

Usual Pediatric Dose for Nausea or Vomiting:

Age 12 and over:
Recommended dose of 8–16 mg taken orally, divided into doses
Maximum dose: 24 mg/day, in divided doses

The dosage should be reduced as soon as possible.

Use: severe nausea and vomiting

Do I be concerned if I miss a dose?

Do the medication as quickly as you can. However, do not take your missed dose in case it's nearing time to take the next dose. Don't take two doses at the same time.

What will happen if I take excessively?

Get medical attention immediately, or contact us for help at the Poison Help Line at 1-800-222-1222. A perphenazine overdose could be fatal.

What should be avoided?

Avoid driving and other hazardous activities until you understand how perphenazine affects your body. Drowsiness, dizziness, or confusion can cause accidents, falls, or even serious injuries. Be careful not to get up too fast from a lying or sitting place, as you could get dizzy. Do not drink alcohol. It may cause an increase in the negative effects of perphenazine.

Avoid exposure to the sun as well as tanning beds. Perphenazine may cause skin to burn more quickly. Be sure to wear protective attire and sunblock (SPF 30 or more) in the outdoors.

Interaction with other drugs

Combining perphenazine with other medications that cause you to sleep or cause your breathing to slow down could result in life-threatening or dangerous adverse consequences. Ask your doctor prior to taking opioids or a sleeping pill, a muscle relaxer, or medication for anxiety or seizures.

Perphenazine is a drug that can be affected by a variety of drugs. This includes over-the-counter and prescription medications, vitamins, and herbal supplements. The interactions between these products are not mentioned here. Discuss with your physician your current medications as well as any new medications you are about to start or stop taking.




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