Prescription medication · Typical Antipsychotic (Phenothiazine)

perphenazine

Also sold as Trilafon. Perphenazine is used to treat schizophrenia in adults.

Data updated 2026-05-15

2,013
FDA reportsRarely reported
5
InteractionsFew interactions
$0.40
Generic price (NADAC)

What the data shows

perphenazine (Trilafon) is a prescription Typical Antipsychotic (Phenothiazine), among the least-reported drugs the FDA tracks (2,013 FDA reports), with 5 documented drug interactions.

Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.

perphenazine (Trilafon) is a prescription Typical Antipsychotic (Phenothiazine). Perphenazine is used to treat schizophrenia in adults.

Perphenazine is a medicine used to treat schizophrenia and control severe nausea and vomiting. It belongs to a class of drugs called typical antipsychotics.

Verify with FDA → · CMS NADAC pricing →

Drug Pricing (NADAC)

Generic Price

$0.40/unit

Generic Available

Yes (9 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

View Alternatives → Compare with Another Drug → Full Side Effects Report →

What it does

Perphenazine is used to treat schizophrenia in adults.

Common side effects

Muscle stiffness or spasms, Restlessness, Slow movements

Key warnings

This medicine may increase the risk of death in elderly patients with dementia-related psychosis.

The sections below are summarized in plain English from perphenazine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Perphenazine works by changing the levels of certain natural chemicals in the brain. These chemicals, called neurotransmitters, help to regulate mood and behavior. By affecting these chemicals, perphenazine can help reduce symptoms of schizophrenia and control nausea.

Side Effects (from patient reports)

Based on 2,013 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for perphenazine, by number of reports

reports

What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.

Source FDA Adverse Event Reporting System (FAERS) As of 2025

Reports over time

Adverse-event reports filed for perphenazine each year to the FDA Adverse Event Reporting System (FAERS).

050100150200 20042007201020132016201920222025 137

Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.

Where perphenazine sits

perphenazine has more FDA adverse-event reports than 13% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.

fewest reports most reports

Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is perphenazine; the line is the median (50th percentile).

FDA Adverse Event Report Analysis

Detailed analysis of 2,013 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.

Total Reports

2,013

Reports Mentioning Death

221

11.0% of reports — not proof of cause

Hospitalization Reports

971

Top Indication

Product Used For Unknown Indication

Gender Distribution

Female 1,027 (56%)
Male 810 (44%)

Age Distribution

0–17 58
18–44 528
45–64 486
65–74 145
75+ 151

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
2 TOXICITY TO VARIOUS AGENTS 274
3 WEIGHT INCREASED 222
4 AKATHISIA 184
5 SUICIDE ATTEMPT 180
7 OBSESSIVE-COMPULSIVE DISORDER 163
8 INCREASED APPETITE 155
9 EUPHORIC MOOD 153
11 ANTIPSYCHOTIC DRUG LEVEL BELOW THERAPEUTIC 149
12 DISINHIBITION 148
13 THERAPEUTIC PRODUCT EFFECT INCOMPLETE 142
14 THERAPEUTIC PRODUCT EFFECT VARIABLE 140
15 LEUKOPENIA 139
16 DRUG INTERACTION 125
17 HYPERTENSION 117
18 FATIGUE 106

Reactions in Death Reports

COMPLETED SUICIDE 87
TOXICITY TO VARIOUS AGENTS 53
DEATH 39
CARDIAC ARREST 29
BRADYCARDIA 17
ATRIOVENTRICULAR BLOCK 14
SEIZURE 14
HYPOTENSION 13
SOMNOLENCE 13
DYSPNOEA 10

Reactions in Hospitalization Reports

TOXICITY TO VARIOUS AGENTS 230
WEIGHT INCREASED 179
SUICIDE ATTEMPT 175
AKATHISIA 166
OBSESSIVE-COMPULSIVE DISORDER 152
INCREASED APPETITE 151
EUPHORIC MOOD 150
ANTIPSYCHOTIC DRUG LEVEL BELOW THERAPEUTIC 148
DISINHIBITION 148
THERAPEUTIC PRODUCT EFFECT INCOMPLETE 140

Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

This medicine may increase the risk of death in elderly patients with dementia-related psychosis. Perphenazine is not approved to treat dementia-related psychosis. Talk to your doctor about the risks if you are an older adult with dementia.

Known Drug Interactions

minor sertraline

Among these are tricyclic antidepressants and selective serotonin reuptake inhibitors, e.g., fluoxetine, sertraline and paroxetine.

Mechanism: Sertraline can slow down how your body breaks down perphenazine, which could lead to higher levels of the drug in your system.

minor fluoxetine

Among these are tricyclic antidepressants and selective serotonin reuptake inhibitors, e.g., fluoxetine, sertraline and paroxetine.

Mechanism: Fluoxetine can interfere with the way your body processes perphenazine, potentially causing the medication to build up in your body.

minor darunavir

perphenazine, risperidone, thioridazine ↑ antipsychotics A decrease in the dose of antipsychotics that are metabolized by CYP3A or CYP2D6 may be needed when co-administered with darunavir/ritonavir.

Mechanism: Darunavir stops the body from breaking down perphenazine normally, which can cause the drug to build up to higher levels.

minor desvenlafaxine

Examples desipramine, atomoxetine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine 7.2 Drugs Having No Clinically Important Interactions with PRISTIQ Based on pharmacokinetic studies, no dosage adjustment is required for drugs that are mainly metabolized by CYP3A4 (e.g., midazolam), or for drugs that are metabolized by both CYP2D6 and CYP3A4 (e.g., tamoxifen, aripiprazole), when administered concomitantly with PRISTIQ [see Clinical Pharmacology (12.3) ].

Mechanism: This combination can affect how your liver clears perphenazine from your body, which might slightly increase the risk of side effects.

minor paroxetine

Examples propafenone, flecainide, atomoxetine, desipramine, dextromethorphan, metoprolol, nebivolol, perphenazine, tolterodine, venlafaxine, risperidone.

Mechanism: Paroxetine slows down the process that clears perphenazine from your system. This leads to higher amounts of the medication in your body than intended.

This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.

Common Questions

Can I drink alcohol while taking perphenazine?
You should avoid alcohol while taking perphenazine, as it can increase drowsiness and other side effects.
How long does it take for perphenazine to start working?
It may take several weeks for you to feel the full effects of perphenazine. Talk to your doctor if you don't notice any improvement in your symptoms.
Can I stop taking perphenazine suddenly?
Do not stop taking perphenazine without talking to your doctor. Stopping suddenly can cause withdrawal symptoms.
Will perphenazine interact with other medications I'm taking?
Perphenazine can interact with other medications. Tell your doctor about all the medicines you take, including prescription and over-the-counter drugs, vitamins, and herbal supplements.
Can perphenazine cause weight gain?
Yes, weight gain is a common side effect of perphenazine.
What should I do if I experience muscle stiffness or spasms?
Tell your doctor if you experience muscle stiffness or spasms. They may prescribe another medicine to help.
Can perphenazine cause drowsiness?
Yes, perphenazine can cause drowsiness. Be careful when driving or operating machinery.
Is it safe to take perphenazine if I have liver problems?
You should not take perphenazine if you have liver damage.
What are the symptoms of tardive dyskinesia?
Tardive dyskinesia causes movements you can't control, like sticking out your tongue, puffing your cheeks, or chewing.
Can perphenazine cause changes in my heart rhythm?
Yes, perphenazine can cause changes in your heart rhythm. Your doctor may want to monitor your heart while you are taking this medicine.
What are the common side effects of perphenazine?
The registry lists Muscle stiffness or spasms, Restlessness, Slow movements, Shaking, Weight gain among the most-reported FAERS reaction terms for perphenazine. The compiled record contains 2,013 FDA adverse-event reports. These counts are not an individual symptom assessment.
Does perphenazine interact with other medications?
The registry has 5 documented interaction rows for perphenazine. Notable source-record pairings include sertraline, fluoxetine, darunavir. These rows are not a complete medication review.
What drug class is perphenazine?
perphenazine belongs to the Typical Antipsychotic (Phenothiazine) drug class. It requires a prescription (Rx). Perphenazine is used to treat schizophrenia in adults.
What pregnancy or breastfeeding source fields are listed for perphenazine?
The FDA label for perphenazine contains product-specific pregnancy or breastfeeding language. PlainMeds does not apply that source text to an individual.

Related Medications in Typical Antipsychotic (Phenothiazine)

Other drugs grouped near perphenazine - same-class peers and common alternatives.

acamprosate

Campral

Acamprosate is a medicine that can help you stay away from alcohol if you are alcohol-dependent and have already stopped drinking.

Compare with perphenazine →

alprazolam

Xanax

Alprazolam (Xanax) is a medication that can help you with anxiety and panic disorders.

Compare with perphenazine →

amitriptyline

Elavil

Amitriptyline is a medicine used to treat depression.

Compare with perphenazine →

amphetamine/dextroamphetamine

Adderall, Adderall XR

Adderall XR is a stimulant medicine.

Compare with perphenazine →

aripiprazole

Abilify

Aripiprazole (Abilify) is a medicine used to treat certain mental disorders and mood problems.

Compare with perphenazine →

Compare perphenazine vs acamprosate side-by-side →

Compare beyond drug class

Nationwide peers by FAERS volume & death-report share

Two PlainMeds-derived comparison paths for perphenazine: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.

Similar FAERS report volume

Nearest drugs by total FAERS reports. This record: 2,013.

4 peers

Similar death-report share

Nearest drugs by FAERS death-report share. This record: 10.98%.

4 peers

Medication Guides

Understanding Drug Interactions

How CYP450 enzymes, inhibitors, and inducers affect your medications

Generic vs Brand Name Drugs

FDA requirements, cost savings, and when the difference matters

Narrow Therapeutic Index Drugs

FDA bioequivalence and label-record context for narrow therapeutic index medicines

Common Drug Interactions

Dangerous medication combinations and how to protect yourself

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What the FDA Data Shows for perphenazine

The FDA label for perphenazine (sold under brand names such as Trilafon) classifies it as a prescription-only medication in the Typical Antipsychotic (Phenothiazine) class. Perphenazine is used to treat schizophrenia in adults. Official labeling lists 8 commonly reported side effects, including Muscle stiffness or spasms, Restlessness, Slow movements.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 2,013 voluntary reports. The database also lists 5 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.40.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.

Last updated: November 14, 2024

PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.

Read our methodology - how this data is sourced, computed, and verified.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.

All federal data sources used on this page