Reported Reactions

Adverse event reports that FDA received

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Therapeutic response decreased adverse event reports that record this term

Kind of term
MedDRA preferred term
Plain meaning
the medicine worked less well

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 59,386 adverse event reports that record the MedDRA preferred term Therapeutic response decreased. In plain words, the term means: the medicine worked less well. The person who codes a report selects the term that agrees best with the description of the reporter.

FDA received 3,778 reports in the 12 months to June 2026 and 4,159 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 207 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, 3,778 (0.3%) record this term. Reports for patients 75 and over were 5.5% of the reports that record this term and 9.5% 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

The medicine worked less well. 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 80 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 Therapeutic response decreased name as a suspect product, in order of name
DrugClassReports with this term
Acetaminophen361
ActemraInterleukin-6 receptor antagonist1,548
AdalimumabTumor necrosis factor blocker723
Albuterol sulfatebeta2-Adrenergic agonist251
Alendronate sodiumBisphosphonate296
Alendronic Acid326
Allegra460
Allegra AllergyHistamine-1 receptor antagonist327
AranespErythropoiesis-stimulating agent467
AravaAntirheumatic agent1,046
AzathioprinePurine antimetabolite561
Baclofengamma-Aminobutyric acid-ergic agonist352
BotoxAcetylcholine release inhibitor692
BOTOX CosmeticAcetylcholine release inhibitor3,684
BuprenorphinePartial opioid agonist326
CarboplatinPlatinum-based drug265
CelebrexNonsteroidal anti-inflammatory drug387
Certolizumab pegolTumor necrosis factor blocker356
Cetirizine hydrochlorideHistamine-1 receptor antagonist345
Cetirizine hydrochloride, pseudoephedrine hydrochlorideHistamine-1 receptor antagonist256
CialisPhosphodiesterase 5 inhibitor731
CimziaTumor necrosis factor blocker779
Codeine256
Cortisone acetateCorticosteroid282
CosentyxInterleukin-17A antagonist888
CyclophosphamideAlkylating drug476
CyclosporineCalcineurin inhibitor immunosuppressant426
DesoximetasoneCorticosteroid295
DexamethasoneCorticosteroid498
Diclofenac sodiumNonsteroidal anti-inflammatory drug387
DupilumabInterleukin-4 receptor alpha antagonist319
DupixentInterleukin-4 receptor alpha antagonist8,968
Duragesic-100271
EnbrelTumor necrosis factor blocker6,917
EpogenErythropoiesis-stimulating agent401
Erelzi477
EtanerceptTumor necrosis factor blocker258
Folic acid417
FosamaxBisphosphonate484
GolimumabTumor necrosis factor blocker303
Humira1,296
HydroxychloroquineAntimalarial846
Hydroxychloroquine sulfateAntimalarial773
ImatinibKinase inhibitor276
InfliximabTumor necrosis factor blocker739
Invega SustennaAtypical antipsychotic452
Invega TrinzaAtypical antipsychotic278
KevzaraInterleukin-6 receptor antagonist437
Krystexxa278
LeflunomideAntirheumatic agent1,043
Lioresal (baclofen)gamma-Aminobutyric acid-ergic agonist564
Lyrica267
MethotrexateFolate analog metabolic inhibitor2,452
Methotrexate sodiumFolate analog metabolic inhibitor441
MethylprednisoloneCorticosteroid262
Mycophenolate mofetilAntimetabolite immunosuppressant479
Myochrysine250
NaproxenNonsteroidal anti-inflammatory drug371
NplateThrombopoietin receptor agonist913
OrenciaSelective T cell costimulation modulator1,382
OtezlaPhosphodiesterase 4 inhibitor1,123
Phthalylsulfathiazole267
PlaquenilAntimalarial570
PrednisoloneCorticosteroid357
PrednisoneCorticosteroid1,425
ProcritErythropoiesis-stimulating agent273
RemicadeTumor necrosis factor blocker1,932
RevlimidThalidomide analog345
RituxanCD20-directed cytolytic antibody488
RituximabCD20-directed cytolytic antibody1,522
SimponiTumor necrosis factor blocker1,083
StelaraInterleukin-12 antagonist1,263
SulfasalazineAminosalicylate1,111
Tiotropium bromideAnticholinergic255
TocilizumabInterleukin-6 receptor antagonist543
XeljanzJanus kinase inhibitor639
XeominAcetylcholine release inhibitor728
XolairAnti-IgE295
XyremCentral nervous system depressant529
Xyzal Allergy 24HRHistamine-1 receptor antagonist252

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 57 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 Therapeutic response decreased name, in order of name
ClassReports with this term
Acetylcholine release inhibitor5,215
Alkylating drug727
alpha-Adrenergic agonist278
Aminosalicylate1,148
Anthracycline topoisomerase inhibitor277
Anti-epileptic agent694
Anti-IgE546
Anticholinergic434
Antimalarial2,196
Antimetabolite immunosuppressant597
Antirheumatic agent2,089
Atypical antipsychotic2,357
Benzodiazepine460
beta2-Adrenergic agonist421
Bisphosphonate872
Blood coagulation factor428
Calcineurin inhibitor immunosuppressant880
CD20-directed cytolytic antibody2,263
Central nervous system depressant544
Central nervous system stimulant420
Corticosteroid5,114
Erythropoiesis-stimulating agent1,167
Folate analog metabolic inhibitor2,934
gamma-Aminobutyric acid-ergic agonist939
Histamine-1 receptor antagonist1,866
Insulin analog552
Integrin receptor antagonist352
Interleukin-12 antagonist1,398
Interleukin-17A antagonist1,106
Interleukin-23 antagonist268
Interleukin-4 receptor alpha antagonist9,287
Interleukin-6 receptor antagonist2,578
Janus kinase inhibitor1,114
Kinase inhibitor1,386
Leukotriene receptor antagonist315
Microtubule inhibitor307
Nonsteroidal anti-inflammatory drug2,545
Nucleoside metabolic inhibitor652
Opioid agonist1,147
Partial opioid agonist480
Phosphodiesterase 4 inhibitor1,306
Phosphodiesterase 5 inhibitor784
Platinum-based drug580
Prostaglandin analog288
Proteasome inhibitor360
Proton pump inhibitor453
Purine antimetabolite668
Selective T cell costimulation modulator1,491
Serotonin reuptake inhibitor476
Serotonin-1b and Serotonin-1d receptor agonist280
Standardized chemical allergen394
Tetracycline-class drug294
Thalidomide analog521
Thrombopoietin receptor agonist1,032
Topoisomerase inhibitor262
Tumor necrosis factor blocker13,377
Vascular endothelial growth factor inhibitor327

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

Reports by month

Reports that record Therapeutic response decreased, by month, five years to June 2026
05001,00020222023202420252026

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 Therapeutic response decreased
AgeReportsShareShare as a bar
Under 22010.3%
2 to 111,2082%
12 to 171,1872%
18 to 448,55714.4%
45 to 6412,94721.8%
65 to 745,0508.5%
75 and over3,2445.5%
Age not given26,99245.5%
Sex of the patient in the reports that record Therapeutic response decreased
SexReportsShareShare as a bar
Female31,33752.8%
Male20,11533.9%
Unknown or not given7,93413.4%

Age and sex are as the report gives them. 74.4% of these reports give the United States as the country.

Terms near this one

Official pages

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Reported Reactions. Therapeutic response decreased: adverse event reports that record this term. https://reportedreactions.com/reaction/therapeutic-response-decreased/ 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 Therapeutic response decreased mean in an adverse event report?

In plain words: the medicine worked less well. 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 .