PDR Health


What is Trilafon?

Trilafon (perphenazine) is a phenothiazine antipsychotic medication. It works by changing the actions of chemicals in your brain.

Perphenazine is used to treat schizophrenia and severe problems with nausea and vomiting.


Health Benefits

Trilafon may be prescribed to treat schizophrenia, a mental disorder that affects a person’s ability to think, feel, and behave clearly. This drug can help by reducing hallucinations, delusions, and disorganized thinking.

Trilafon is also sometimes used to treat severe nausea and vomiting. This medication can help by blocking dopamine, a chemical messenger in the brain that plays a role in these symptoms.

Side Effects

The most common side effects of Trilafon include:


dry mouth

blurred vision


weight gain

If these side effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include the following:

drowsiness that is so severe you can’t be active or wake up

uncontrollable twitching or muscle spasms

seizures (convulsions)

slow heart rate

low blood pressure



agitation or restlessness

trouble breathing

jaundice (yellowing of the skin or eyes)

enlarged breasts in men

inability to have an erection

missed menstrual periods

Dosage and Forms Available

Trilafon is available as an oral tablet and an oral solution. The usual starting dose for adults with schizophrenia is 8 mg per day. Your doctor may gradually increase your dose until you reach the best dosage for you.

For children ages 5-16, the usual starting dose is 0.5 mg per day. The doctor will gradually increase the child’s dose until they reach the best dosage for them.

Trilafon oral solution is a clear, colorless liquid that contains 8 mg of perphenazine in each mL.


Some drugs can interact with Trilafon and cause a serious condition called neuroleptic malignant syndrome (NMS). Be sure your doctor knows if you also take medicine for depression, Parkinson’s disease, migraine headaches, serious infections, or prevention of nausea and vomiting. Tell your doctor about all other medications you use.

You should not take Trilafon if you are allergic to perphenazine or any other phenothiazines.

To make sure this medicine is safe for you, tell your doctor if you have ever had:

liver disease

kidney disease

a blood disorder or low white blood cell counts

heart disease or slow heartbeats

a history of seizures (convulsions)

trouble urinating


It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

You should not breast-feed while using this medicine.

Older adults may be more sensitive to the side effects of this drug, especially drowsiness, constipation, trouble urinating, and seizures. These side effects can increase the risk of falling.

Mechanism of Action

The exact mechanism of action of Trilafon is unknown. It is thought to work by blocking dopamine receptors in the brain. Dopamine is a neurotransmitter, or chemical messenger, that plays a role in some of the symptoms of schizophrenia.


Trilafon is well absorbed from the gastrointestinal tract and has an onset of action within 30-60 minutes. The peak effect occurs in 2-4 hours. Trilafon is widely distributed throughout the body and crosses the blood-brain barrier. Trilafon is metabolized in the liver and excreted in the urine. The half-life of Trilafon is 12 hours.

Pregnancy and Lactation

Trilafon should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. The effects of Trilafon on labor and delivery are unknown. Trilafon is present in human milk in low concentrations. Because of the potential for serious adverse reactions in nursing infants from Trilafon, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Alternatives to Trilafon

Some alternatives to Trilafon include other antipsychotics such as:

Thorazine (chlorpromazine)

Haldol (haloperidol)

Prolixin (fluphenazine)

Mellaril (thioridazine)

Navane (thiothixene)

Orap (pimozide)

Loxitane (loxapine)

Serentil (mesoridazine)

Discuss any concerns or questions about these alternative medications with your doctor.