Reported Reactions

Adverse event reports that FDA received

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Lethargy adverse event reports that record this term

Kind of term
MedDRA preferred term
Plain meaning
sluggishness

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.

Reports on file

From January 2004 to June 2026, FDA received 56,473 adverse event reports that record the MedDRA preferred term Lethargy. In plain words, the term means: sluggishness. The person who codes a report selects the term that agrees best with the description of the reporter.

FDA received 2,696 reports in the 12 months to June 2026 and 2,768 in the 12 months before. FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

By reports in the 12 months to June 2026, this term was number 277 of 1,436 reaction terms with a page. Of the 1,332,454 drug reports that FDA received in the 12 months to June 2026, 2,696 (0.2%) record this term. Reports for male patients were 38.9% of the reports that record this term and 34.6% of all drug reports.

The number of people who use the product is not in the data. A count is not a rate.

MedDRA

The Medical Dictionary for Regulatory Activities. The person who codes a report selects the preferred term that agrees best with the description of the reporter. FDA does not publish the description.

Plain meaning

Sluggishness. The words are from the fixed dictionary of this site. They add nothing to a report.

Data version

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

Drugs in these reports

The table has the 47 drug pages with 250 or more reports that record this term. The rows are in order of name. A drug page with fewer reports for this term is not in the table. The counts are the counts that the site keeps for each reaction term, and a count can be lower than the count of FDA.

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 .

Drugs that the reports with the term Lethargy name as a suspect product, in order of name
DrugClassReports with this term
AbilifyAtypical antipsychotic261
Acetaminophen318
AmlodipineCalcium channel blocker452
AvonexInterferon beta252
Baclofengamma-Aminobutyric acid-ergic agonist314
ChantixPartial cholinergic nicotinic agonist383
ClonazepamBenzodiazepine319
ClozapineAtypical antipsychotic284
ClozarilAtypical antipsychotic255
CosentyxInterleukin-17A antagonist331
CyclophosphamideAlkylating drug285
Cymbalta1,736
DexamethasoneCorticosteroid343
DupixentInterleukin-4 receptor alpha antagonist407
EnbrelTumor necrosis factor blocker660
EntrestoAngiotensin 2 receptor blocker369
Epidiolex251
FentanylOpioid agonist260
ForteoParathyroid hormone analog360
GabapentinAnti-epileptic agent550
GilenyaSphingosine 1-phosphate receptor modulator263
Humira1,046
IbuprofenNonsteroidal anti-inflammatory drug367
LamotrigineAnti-epileptic agent283
LorazepamBenzodiazepine284
Lyrica416
MetforminBiguanide270
MethotrexateFolate analog metabolic inhibitor567
MorphineOpioid agonist311
Morphine sulfateOpioid agonist325
NuplazidAtypical antipsychotic397
OlanzapineAtypical antipsychotic296
OmeprazoleProton pump inhibitor383
Oxycodone hydrochlorideOpioid agonist263
OxyContinOpioid agonist381
PaxilSerotonin reuptake inhibitor403
PrednisoneCorticosteroid381
RepathaPCSK9 inhibitor286
RevlimidThalidomide analog578
RibavirinNucleoside analog antiviral423
RisperidoneAtypical antipsychotic308
RituximabCD20-directed cytolytic antibody287
SeroquelAtypical antipsychotic359
SertralineSerotonin reuptake inhibitor288
TysabriIntegrin receptor antagonist398
XtandiAndrogen receptor inhibitor252
XyremCentral nervous system depressant354

The page of each drug has the count of each reaction term in its reaction lookup.

Drug classes in these reports

The table has the 55 pharmacologic classes with 250 or more reports that record this term. The rows are in order of name.

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 .

Pharmacologic classes of the drugs that the reports with the term Lethargy name, in order of name
ClassReports with this term
Alkylating drug440
Aminoketone450
Androgen receptor inhibitor323
Angiotensin 2 receptor blocker664
Angiotensin converting enzyme inhibitor459
Anti-epileptic agent1,972
Atypical antipsychotic3,569
Benzodiazepine1,648
beta-Adrenergic blocker851
Biguanide469
Bisphosphonate280
Calcium channel blocker503
CD20-directed cytolytic antibody786
Central alpha-2 adrenergic agonist293
Central nervous system depressant409
Central nervous system stimulant480
Corticosteroid1,332
Endothelin receptor antagonist552
Factor Xa inhibitor424
Folate analog metabolic inhibitor689
gamma-Aminobutyric acid-ergic agonist531
GLP-1 receptor agonist1,221
HER2/neu receptor antagonist343
Histamine-1 receptor antagonist453
HMG-CoA reductase inhibitor645
Human immunoglobulin G271
Insulin analog341
Integrin receptor antagonist607
Interferon beta400
Interleukin-17A antagonist361
Interleukin-4 receptor alpha antagonist434
Janus kinase inhibitor408
Kinase inhibitor2,065
l-Thyroxine375
Loop diuretic295
Microtubule inhibitor378
Mood stabilizer502
Nonsteroidal anti-inflammatory drug1,019
Nucleoside analog antiviral459
Nucleoside metabolic inhibitor822
Opioid agonist2,742
Parathyroid hormone analog362
Partial cholinergic nicotinic agonist393
PCSK9 inhibitor361
Platinum-based drug530
Programmed death Receptor-1 blocking antibody307
Prostacycline vasodilator584
Proton pump inhibitor763
Serotonin and norepinephrine reuptake inhibitor653
Serotonin reuptake inhibitor2,228
Sphingosine 1-phosphate receptor modulator312
Thalidomide analog955
Tumor necrosis factor blocker1,437
Vascular endothelial growth factor inhibitor266
Vesicular monoamine transporter 2 inhibitor291

A class with many reports in all has many reports for almost every term.

Reports by month

Reports that record Lethargy, 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.

Patients in these reports

Age of the patient in the reports that record Lethargy
AgeReportsShareShare as a bar
Under 29561.7%
2 to 111,7433.1%
12 to 171,2762.3%
18 to 448,29514.7%
45 to 6412,62522.4%
65 to 746,70611.9%
75 and over6,27111.1%
Age not given18,60132.9%
Sex of the patient in the reports that record Lethargy
SexReportsShareShare as a bar
Female29,35752%
Male21,95838.9%
Unknown or not given5,1589.1%

Age and sex are as the report gives them. 69.2% of these reports give the United States as the country.

Terms near this one

Official pages

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Reported Reactions. Lethargy: adverse event reports that record this term. https://reportedreactions.com/reaction/lethargy/ 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.

The count has the reports with each spelling of one MedDRA preferred term. 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

What does Lethargy mean in an adverse event report?

In plain words: sluggishness. It is a MedDRA preferred term. FDA codes the description of a reporter with the MedDRA dictionary. The openFDA files do not have the description itself, and this site does not show it.

Does a drug in the table mean that the drug was responsible for this reaction?

No. FDA says:

No individual drug is connected to any individual reaction.

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

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 .

What does this page tell a person who has this symptom?

This page gives counts of reports. It cannot assess a person. A pharmacist or a clinician can assess a person.

If this is a medical emergency, please call 911.

Source: FDA, MedWatch Online Voluntary Reporting Form. The site read the page on .