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naltrexone Side Effects

Also known as: Vivitrol, ReVia

Analysis of 29,813 adverse event reports submitted to the FDA from 2004 to 2025.

Total Reports

29,813

Death-Related

1,301

4.4% of reports

Hospitalizations

3,715

12.5% of reports

Top Indication

Alcoholism

Most Reported Adverse Reactions

INJECTION SITE REACTION
4,407
INJECTION SITE PAIN
3,111
NAUSEA
2,094
ALCOHOLISM
1,942
INJECTION SITE MASS
1,895
FATIGUE
1,781
PAIN
1,626
DRUG INEFFECTIVE
1,498
HEADACHE
1,479
FEELING ABNORMAL
1,385
OFF LABEL USE
1,383
DRUG DEPENDENCE
1,369
MALAISE
1,239
INSOMNIA
1,141
ANXIETY
1,083
DIZZINESS
1,003
VOMITING
987
DEPRESSION
935
INJECTION SITE INDURATION
897
DECREASED APPETITE
811

Who Reports Side Effects

Gender Distribution

Female 11,958 (47%)
Male 13,161 (52%)
Unknown 65

Age Distribution

0-17 343 (2%)
18-44 9,536 (56%)
45-64 6,269 (37%)
65-74 705 (4%)
75+ 139 (1%)

Reporting Trend by Year

2004 2025

Reactions in Death Reports

Top reactions reported in 1,301 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
DEATH 556
OVERDOSE 321
COMPLETED SUICIDE 155
DRUG DEPENDENCE 74
TOXICITY TO VARIOUS AGENTS 63
DRUG ABUSE 44
OFF LABEL USE 32
DRUG DOSE OMISSION 31
TREATMENT NONCOMPLIANCE 24
PRODUCT DOSE OMISSION 20
ALCOHOLISM 19
ROAD TRAFFIC ACCIDENT 18
SUSPECTED SUICIDE 18
FALL 17
PNEUMONIA 17
CARDIO-RESPIRATORY ARREST 15
PRODUCT DOSE OMISSION ISSUE 15
ACCIDENTAL OVERDOSE 14
CARDIAC ARREST 13
INTENTIONAL OVERDOSE 13

Reactions in Hospitalization Reports

Top reactions in 3,715 reports where hospitalization was an outcome.

Reaction Reports
HOSPITALISATION 437
ALCOHOLISM 261
NAUSEA 231
INJECTION SITE REACTION 226
PAIN 225
VOMITING 191
INJECTION SITE PAIN 181
DRUG INEFFECTIVE 168
DRUG DEPENDENCE 156
ANXIETY 144
DYSPNOEA 140
MALAISE 140
OVERDOSE 139
PNEUMONIA 139
SUICIDAL IDEATION 134
DRUG WITHDRAWAL SYNDROME 127
FALL 127
FATIGUE 127
HEADACHE 127
DEPRESSION 124

Nearby — Related Medications

Compare naltrexone vs acamprosate →

What the FAERS Data Reveals About naltrexone Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 29,813 voluntary reports linked to naltrexone and its brand equivalents (Vivitrol, ReVia), spanning 2004 through 2025. Of those, 1,301 (4.4%) listed death as an outcome and 3,715 (12.5%) involved hospitalization. The most common indication reported alongside adverse events was Alcoholism.

Demographic breakdowns help contextualize who is being exposed to the drug. Of reports with known sex, 47% were female and 52% male; age distribution skews toward 18-44, with 9,536 reports in that bracket. The single most reported reaction is injection site reaction with 4,407 submissions, followed by injection site pain and nausea.

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.