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methadone Side Effects

Also known as: Dolophine

Analysis of 41,632 adverse event reports submitted to the FDA from 2003 to 2025.

Total Reports

41,632

Death-Related

13,420

32.2% of reports

Hospitalizations

11,019

26.5% of reports

Top Indication

Product Used For Unknown Indication

Most Reported Adverse Reactions

DRUG DEPENDENCE
5,614
TOXICITY TO VARIOUS AGENTS
5,213
DRUG ABUSE
4,797
OVERDOSE
3,840
PAIN
3,671
DEATH
3,519
EMOTIONAL DISTRESS
2,385
DRUG WITHDRAWAL SYNDROME
2,343
DRUG INEFFECTIVE
1,722
FOETAL EXPOSURE DURING PREGNANCY
1,659
NAUSEA
1,601
DRUG INTERACTION
1,592
ANXIETY
1,336
DRUG WITHDRAWAL SYNDROME NEONATAL
1,334
FATIGUE
1,300
OFF LABEL USE
1,270
VOMITING
1,253
SOMNOLENCE
1,227
COMPLETED SUICIDE
1,084
CARDIAC ARREST
1,035

Who Reports Side Effects

Gender Distribution

Female 16,431 (44%)
Male 20,593 (55%)
Unknown 174

Age Distribution

0-17 1,540 (6%)
18-44 11,902 (46%)
45-64 9,815 (38%)
65-74 2,086 (8%)
75+ 716 (3%)

Reporting Trend by Year

2003 2025

Reactions in Death Reports

Top reactions reported in 13,420 reports where death was an outcome. These are voluntarily reported and do not establish causation.

Reaction Reports
TOXICITY TO VARIOUS AGENTS 4,075
DEATH 3,515
DRUG ABUSE 3,155
OVERDOSE 1,357
COMPLETED SUICIDE 1,077
CARDIAC ARREST 852
RESPIRATORY ARREST 712
CARDIO-RESPIRATORY ARREST 697
DRUG DEPENDENCE 664
DRUG INTERACTION 439
POISONING 409
PULMONARY OEDEMA 386
RESPIRATORY DEPRESSION 372
ACCIDENTAL OVERDOSE 341
INTENTIONAL PRODUCT MISUSE 283
PNEUMONIA 276
ASPHYXIA 259
SOMNOLENCE 240
DEPRESSED LEVEL OF CONSCIOUSNESS 236
BRAIN OEDEMA 223

Reactions in Hospitalization Reports

Top reactions in 11,019 reports where hospitalization was an outcome.

Reaction Reports
TOXICITY TO VARIOUS AGENTS 1,131
DRUG ABUSE 1,044
OVERDOSE 746
DRUG DEPENDENCE 693
DRUG INTERACTION 671
PAIN 633
DRUG INEFFECTIVE 611
VOMITING 587
COMA 570
NAUSEA 569
OFF LABEL USE 551
PNEUMONIA 548
SOMNOLENCE 489
DRUG WITHDRAWAL SYNDROME 479
FATIGUE 463
DYSPNOEA 457
RESPIRATORY DEPRESSION 446
CONFUSIONAL STATE 392
DEPRESSED LEVEL OF CONSCIOUSNESS 390
FALL 386

Nearby — Related Medications

Compare methadone vs acamprosate →

What the FAERS Data Reveals About methadone Side Effects

The FDA Adverse Event Reporting System (FAERS) contains 41,632 voluntary reports linked to methadone and its brand equivalents (Dolophine), spanning 2003 through 2025. Of those, 13,420 (32.2%) listed death as an outcome and 11,019 (26.5%) 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, 44% were female and 55% male; age distribution skews toward 18-44, with 11,902 reports in that bracket. The single most reported reaction is drug dependence with 5,614 submissions, followed by toxicity to various agents and drug abuse.

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.