Reported Reactions

Adverse event reports that FDA received

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Methadone hydrochloride adverse event reports that FDA received

Name type
Generic name
Class
Opioid agonist
Also reported as
Methadone Hydrochloride Tablets Usp, Methadone Hydrochloride Tablet Usp 10mg

What a report is

A report is not proof that the drug was the cause of the event.

FDA says:

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.

Source: openFDA, Drug Adverse Event Overview, section "Responsible use of the data". The site read the page on . The data have the reports that FDA received through .

FDA also says:

There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event. The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Source: openFDA, Response of the drug event API (meta.disclaimer). The site read the page on .

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

Drug reports received through . Device reports have a separate cutoff, 30 Sep 2026. Why a report count is not a rate.

Reports on file

From January 2004 to June 2026, FDA received 5,129 adverse event reports that name Methadone hydrochloride. In these reports the drug is a suspect or interacting product.

In the same period, 1,923 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 318 reports in the 12 months to June 2026 and 455 in the 12 months before. FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

Of the 1,332,454 drug reports that FDA received in the 12 months to June 2026, 318 (under 0.1%) name Methadone hydrochloride. Reports from other health professionals were 44.4% of the reports that name Methadone hydrochloride and 19.7% of all drug reports.

The number of people who use the product is not in the data. A count is not a rate. A count of reports is not a count of events or of patients, because one event can have more than one report.

There are many instances of duplicative reports and some reports do not contain all the necessary information.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

Suspect product

FDA records each drug in a report as suspect, concomitant or interacting. This page counts the reports in which Methadone hydrochloride is suspect or interacting. FDA says:

Any number of the drugs may be marked as suspect if thought to be responsible for one or more of the reactions, but that information is not validated.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

Data version

openFDA FAERS release of 29 Oct 2026. Reports received through 30 Jun 2026.

Since the last update

FDA says:

Many factors can influence whether or not an event will be reported, such as the time a product has been marketed and publicity about an event.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

The information in these reports cannot be used to estimate the incidence (occurrence rates) of the events reported.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

The latest update of the FDA data, recorded on , changed no count of this page.

  • In April to June 2026, FDA received 76 reports that name Methadone hydrochloride.
  • In January to March 2026, FDA received 92.
  • In April to June 2025, FDA received 109.

April to June 2026 is the latest closed quarter in the data. A closed quarter is a quarter for which the FDA files have most of the reports.

All updatesFeed of updates (RSS)

Reaction lookup

These are the reaction terms that the reports record, with the number of reports for each term. Type a term or a plain word to find its count.

What this list leaves out

The table lists the 317 reaction terms that 5 or more reports record. A term with fewer than 5 reports is not in the table.

The site keeps reaction terms for 5,088 of the 5,129 reports (99.2%).

The reports of the other years are not in the counts.

So a count in the table can be lower than the count of FDA.

The table shows the first 50 of 317 terms.

Reaction terms in the reports that name Methadone hydrochloride, most reports first
Reaction term (MedDRA) and plain meaningReportsShare of the 5,129 reports
Toxicity to various agentspoisoning or toxic effect of one or more substances1,00719.6%
Overdosea dose above the recommended amount67913.2%
Drug abusemisuse of a medicine56411%
Dependence52210.2%
Drug dependencedependence on a medicine5059.8%
Foetal exposure during pregnancythe unborn baby was exposed to the medicine3967.7%
Exposure during pregnancythe medicine was taken during pregnancy3506.8%
Deaththe patient died; cause not stated by this term3476.8%
Drug withdrawal syndrome neonatal3276.4%
Drug interactionan interaction between medicines2454.8%
Painpain, site not specified2274.4%
Developmental delayslower development in a child2134.2%
Learning disability2064%
Somnolencedrowsiness2034%
Emotional distress1943.8%
Anxiety1883.7%
Electrocardiogram QT prolongeda QT prolongation on the ECG1863.6%
Coma1653.2%
Drug withdrawal syndromesymptoms on stopping a medicine1452.8%
Maternal exposure during pregnancythe mother took the medicine during pregnancy1402.7%
Accidental overdosean accidental overdose1392.7%
Respiratory depressionslow or shallow breathing1302.5%
Intentional product misusedeliberate use not as intended1222.4%
Drug diversion1152.2%
Miosis1102.1%
Cardiac arrestthe heart stopped1042%
Poisoning951.9%
Drug use disorder881.7%
Drug ineffectivethe medicine did not work as expected861.7%
Vomitingbeing sick841.6%
Pneumonialung infection811.6%
Depressed level of consciousness801.6%
Completed suicidedeath by suicide781.5%
Confusional stateconfusion781.5%
Drug level increaseda raised blood level of the medicine751.5%
Substance use disorder741.4%
Withdrawal syndrome741.4%
Respiratory arrestbreathing stopped731.4%
Nauseafeeling sick721.4%
Torsade de pointesa serious irregular heart rhythm721.4%
Pulmonary oedemafluid in the lungs711.4%
Bradypnoea671.3%
Constipation671.3%
Loss of consciousnesspassing out651.3%
Rhabdomyolysismuscle breakdown651.3%
Agitationrestlessness621.2%
Pneumonia aspirationlung infection from breathing in material591.2%
Vision abnormal neonatal591.2%
Unresponsive to stimuli581.1%
Depressionlow mood551.1%

Download all 317 terms of Methadone hydrochloride (CSV)

The counts add to more than 5,129 reports, because one report can record more than one term. FDA says:

No individual drug is connected to any individual reaction. When a report lists multiple drugs and multiple reactions, there is no way to conclude from the data therein that a given drug is responsible for a given reaction.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

The CSV file has the same rows and the same limits. Its last row is a note that says so.

MedDRA term

The person who codes a report selects the preferred term that agrees best with the description of the reporter. The words under a term are the plain meaning that this site gives.

Not the label

The FDA-approved label of a product lists its adverse reactions. See the official pages at the end of this page.

Same ingredient, other names

Reporters write a brand name or a generic name. Each name has its own page and its own count.

Names of Methadone with a page, in the order generic names, brand names, names as reported
NameName typeReports
MethadoneGeneric name24,293
Methadone hydrochloride (this page)Generic name5,129
MethadoseBrand name3,672

Sum of the separately reported names: 33,094. A report that names two of these names is in the sum two times. The sum is not the number of reports for the ingredient.

FDA says:

Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

Outcomes by year

The table gives the outcomes that the reporters gave, in the terms of FDA.

Outcomes in the reports that name Methadone hydrochloride, by the year of the openFDA file that holds the report

The table continues to the right.

Year of the openFDA fileReportsSeriousDeathLife-threateningHospitalization (initial or prolonged)Disability or Permanent DamageCongenital Anomaly/Birth DefectOther Serious (Important Medical Events)Not serious
2004661050020
200510105140030
2006686864060000
200713125051141
2008888010000
200944411462210213
201033331541310110
201188825112600286
2012868313423224313
201343421441701121
2014212013140161
20153532180600123
201648431871700185
201714613772569011029
20183693632661850013046
201939726597116121225132
2020464349215328127172115
20216725091103810011127410163
20225063961252814541262110
2023736660192449471354076
20246686351972712910744833
2025485450117521586231635
20261831574427582111526

An outcome in a report is not proof that the drug was the cause. The reporter gives the outcome, and FDA does not verify it. FDA says:

The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

The six headings with the names of FDA are the outcome terms of FDA. A report can have more than one outcome. The columns Serious and Not serious are the two values of the openFDA field serious. For the value serious, openFDA gives this description:

The adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition

Source: openFDA, Drug adverse event fields (YAML reference). The site read the page on .

The year is the year of the openFDA file that holds the latest version of the report. It is not always the year in which FDA first received the report. The chart of the next section uses the year of first receipt. The latest year is not complete.

Reports by year and month

Reports that name Methadone hydrochloride, by the year in which FDA received them
05001,000200420082012201620202024

The column of 2026 has an outline, because the year is not complete. It has the reports that FDA received through June 2026 only.

Show the figures of the chart as a table
Reports that name Methadone hydrochloride, by the year in which FDA received them
YearReports
20046
20059
200666
200710
200815
200943
201031
201191
201293
201339
201421
201539
201648
2017155
2018393
2019399
2020503
2021694
2022496
2023743
2024650
2025417
2026168
Reports that name Methadone hydrochloride, by month, five years to June 2026
025050020222023202420252026

FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

Why a count moves

A count moves for many reasons. The guide gives FDA's words about them.

Patients and reporters

Age of the patient in the reports that name Methadone hydrochloride
AgeReportsShareShare as a bar
Under 2931.8%
2 to 111302.5%
12 to 17400.8%
18 to 441,42127.7%
45 to 6478015.2%
65 to 741142.2%
75 and over611.2%
Age not given2,49048.5%
Sex of the patient in the reports that name Methadone hydrochloride
SexReportsShareShare as a bar
Female1,86036.3%
Male2,43947.6%
Unknown or not given83016.2%
Type of reporter in the reports that name Methadone hydrochloride
ReporterReportsShareShare as a bar
Physician1,10621.6%
Pharmacist3346.5%
Other health professional2,27644.4%
Lawyer2474.8%
Consumer or non-health professional1,09521.3%
Not given711.4%

Age and sex are as the report gives them. The reporter is the primary source in the report. 42.9% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Methadone hydrochloride record
Indication as recorded (MedDRA)ReportsShare
Drug withdrawal maintenance therapy2685.2%
Drug dependence1933.8%
Pain1633.2%
Drug use disorder1492.9%
Cancer pain561.1%
Foetal exposure during pregnancy270.5%

The reporter fills in the indication, and the field is often empty. Each share is of all 5,129 reports.

Drugs in the same reports

Other drugs that the reports of Methadone hydrochloride name, in any role, in order of name
DrugReports that name the two
Acetaminophen Oxycodone Hydrochloride632
Cocaine484
Diazepam630
Endocet348
Morphine sulfate635
Oxycodone hydrochloride478
OxyContin344
Percocet553
Pregabalin369
Tramadol hydrochloride477

The table has the 10 drug names that these reports name most. Two names in one report says only that the report recorded the two. It says nothing about the part of a product in the event.

FDA says:

Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

Pages near this one

These links are for navigation. No count selected them. The class page lists each drug of the class.

Official pages

The site checked these addresses on . The links open in a new tab.

Cite this page

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Reported Reactions. Methadone hydrochloride: adverse event reports that FDA received. https://reportedreactions.com/drug/methadone-hydrochloride/ Source: U.S. Food and Drug Administration, openFDA Drug Adverse Event (FAERS) files, release of . Reports received through .

Where the data come from

The counts come from the openFDA Drug Adverse Event (FAERS) bulk files, release of 29 Oct 2026. The files have the reports that FDA received through 30 Jun 2026. A drug name is the name on the report. The site matches it to a brand name or a generic name of the National Drug Code Directory of 2 Nov 2026. A class is the pharmacologic class (EPC) of the FDA label.

A report is in the count when it names Methadone hydrochloride as a suspect or interacting product. The 1,923 reports that name it only as a concomitant medicine are not in the count. The site does not publish a report narrative, a lot number, a detail of a patient or the identity of a reporter. The record of FDA is the authority. See how the site counts reports, the data sources and the corrections page.

Questions

Do these reports show that Methadone hydrochloride was responsible for the reactions?

No. FDA says:

For any given report, there is no certainty that a suspected drug caused the event.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

A reaction can relate to the condition that the drug treats, to other medicines, or to something else.

Is this the list of reactions on the label of Methadone hydrochloride?

No. It is a count of what people reported to FDA: 5,129 reports from January 2004 to June 2026. The FDA-approved label of a product lists its adverse reactions. The official pages at the end of this page link to the labels.

Who sent these reports?

Other health professional (44.4%), physician (21.6%) and consumer or non-health professional (21.3%). These are the types of reporter for the reports that name this drug.

If a manufacturer receives an adverse event report, it is normally required to send the report to FDA.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

How does a person report an adverse event?

FDA runs MedWatch, a program that takes voluntary reports from health professionals, patients and consumers. The guide on how to report has the links.