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Drug side effects

perphenazine Side Effects

The reactions most often reported to the FDA for perphenazine (also sold as Trilafon), with demographics, serious outcomes, and reporting trends.

Data updated 2026-05-15

2,013
FAERS reports

Data from the FDA Adverse Event Reporting System (FAERS), 2004 to 2025. A FAERS report records a temporal association, not proof of cause. See our methodology for how figures are compiled and de-duplicated.

The most commonly reported side effects of perphenazine come from 2,013 reports to the FDA, broken down here by frequency, patient demographics, and serious outcomes.

This page analyzes 2,013 reports to the FDA Adverse Event Reporting System (FAERS) for perphenazine (Trilafon): the reactions reported most often, who reported them, serious outcomes such as hospitalization, and year-over-year trends. A FAERS report does not prove the drug caused the effect, and report volume tracks how widely a drug is used, not how likely an effect is for any one person. Educational information, not medical advice.

Total Reports

2,013

Reports Mentioning Death

221

11.0% of reports — not proof the medicine caused the death

Hospitalizations

971

48.2% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

TOXICITY TO VARIOUS AGENTS
274
WEIGHT INCREASED
222
AKATHISIA
184
SUICIDE ATTEMPT
180
OBSESSIVE-COMPULSIVE DISORDER
163
INCREASED APPETITE
155
EUPHORIC MOOD
153
ANTIPSYCHOTIC DRUG LEVEL BELOW THERAPEUTIC
149
DISINHIBITION
148
THERAPEUTIC PRODUCT EFFECT INCOMPLETE
142
THERAPEUTIC PRODUCT EFFECT VARIABLE
140
LEUKOPENIA
139
DRUG INTERACTION
125
HYPERTENSION
117
FATIGUE
106
NAUSEA
97
TARDIVE DYSKINESIA
97

Who Reports Side Effects

Gender Distribution

Female 1,027 (56%)
Male 810 (44%)
Unknown 11

Age Distribution

0-17 58 (4%)
18-44 528 (39%)
45-64 486 (36%)
65-74 145 (11%)
75+ 151 (11%)

Reporting Trend by Year

2004 2025

Reactions in Death Reports

Top reactions reported in 221 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction 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
INTENTIONAL OVERDOSE 10
BRAIN OEDEMA 9
OVERDOSE 9
CONFUSIONAL STATE 7
FALL 7
HYPERAMMONAEMIC ENCEPHALOPATHY 7
BRAIN HERNIATION 6
CARDIO-RESPIRATORY ARREST 6
HEPATOMEGALY 6

Reactions in Hospitalization Reports

Top reactions in 971 reports where hospitalization was an outcome.

Reaction 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
THERAPEUTIC PRODUCT EFFECT VARIABLE 139
LEUKOPENIA 129
DRUG INTERACTION 93
HYPERTENSION 90
LEUKAEMIA 82
FALL 80
OBESITY 75

Compare perphenazine vs acamprosate →

What the FAERS Data Reveals About perphenazine Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 2,013 voluntary reports linked to perphenazine and its brand equivalents (Trilafon), spanning 2004 through 2025. Of those, 221 (11.0%) listed death as an outcome and 971 (48.2%) involved hospitalization. The most common indication reported alongside adverse events was Product Used For Unknown Indication.

Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 56% were female and 44% male; age distribution skews toward 18-44, with 528 reports in that bracket. The single most reported reaction is toxicity to various agents with 274 submissions, followed by weight increased and akathisia.

How to read these numbers

FAERS is a signal-detection tool, not a scorecard. Reports are voluntary, and a single case may list multiple suspect drugs, so numbers above should not be read as incidence rates or per-patient risk. Widely prescribed drugs naturally accumulate more reports than niche therapies even when individual risk is low. These aggregates are useful for spotting patterns that merit further pharmacovigilance, not for choosing between medications. This page is for educational reference only and is not medical advice, speak with a licensed clinician about any side-effect concerns.