Reported Reactions

Adverse event reports that FDA received

  • Search
  • Watch list

Drug resistance adverse event reports that record this term

Kind of term
MedDRA preferred term

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 25,326 adverse event reports that record the MedDRA preferred term Drug resistance. The person who codes a report selects the term that agrees best with the description of the reporter.

FDA received 1,462 reports in the 12 months to June 2026 and 2,078 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 463 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, 1,462 (0.1%) record this term. Reports for female patients were 37.5% of the reports that record this term and 52.7% 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.

Data version

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

Drugs in these reports

The table has the 67 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 Drug resistance name as a suspect product, in order of name
DrugClassReports with this term
AbacavirHuman immunodeficiency virus nucleoside analog reverse transcriptase inhibitor254
AcyclovirHerpes simplex virus nucleoside analog DNA polymerase inhibitor300
AmikacinAminoglycoside antibacterial369
AzithromycinMacrolide antimicrobial315
CarbamazepineMood stabilizer386
CarboplatinPlatinum-based drug493
CiprofloxacinFluoroquinolone antibacterial503
CisplatinPlatinum-based drug409
ClarithromycinMacrolide antimicrobial296
ClobazamBenzodiazepine334
ClopidogrelP2Y12 platelet inhibitor269
CyclophosphamideAlkylating drug713
CyclosporineCalcineurin inhibitor immunosuppressant418
CytarabineNucleoside metabolic inhibitor287
DarunavirProtease inhibitor254
DasatinibKinase inhibitor506
DexamethasoneCorticosteroid460
DoxorubicinAnthracycline topoisomerase inhibitor337
EfavirenzHuman immunodeficiency virus 1 Non-Nucleoside analog reverse transcriptase inhibitor713
EmtricitabineHuman immunodeficiency virus nucleoside analog reverse transcriptase inhibitor350
EnbrelTumor necrosis factor blocker294
EntecavirHepatitis B virus nucleoside analog reverse transcriptase inhibitor313
ErlotinibKinase inhibitor439
Ethambutol417
EtoposideTopoisomerase inhibitor383
FluconazoleAzole antifungal368
GanciclovirCytomegalovirus nucleoside analog DNA polymerase inhibitor590
GefitinibKinase inhibitor477
Glivec285
Humira502
ImatinibKinase inhibitor944
IressaKinase inhibitor760
IsoniazidAntimycobacterial382
LamivudineHepatitis B virus nucleoside analog reverse transcriptase inhibitor1,766
LamotrigineAnti-epileptic agent378
Levetiracetam800
LevofloxacinFluoroquinolone antibacterial396
LinezolidOxazolidinone antibacterial616
MeropenemPenem antibacterial565
MethotrexateFolate analog metabolic inhibitor726
MethylprednisoloneCorticosteroid464
MoxifloxacinFluoroquinolone antibacterial346
Mycophenolate mofetilAntimetabolite immunosuppressant653
NevirapineHuman immunodeficiency virus 1 Non-Nucleoside analog reverse transcriptase inhibitor1,025
NilotinibKinase inhibitor325
OlanzapineAtypical antipsychotic337
OsimertinibKinase inhibitor775
PaclitaxelMicrotubule inhibitor276
PhenytoinAnti-epileptic agent274
PrednisoloneCorticosteroid631
PrednisoneCorticosteroid873
PyrazinamideAntimycobacterial268
RifampinRifamycin antibacterial393
RitonavirCytochrome P450 3A inhibitor494
RituximabCD20-directed cytolytic antibody670
Stavudine435
TacrolimusCalcineurin inhibitor immunosuppressant634
TagrissoKinase inhibitor263
Tenofovir357
Tenofovir disoproxil fumarateHepatitis B virus nucleoside analog reverse transcriptase inhibitor445
Topiramate411
ValganciclovirCytomegalovirus nucleoside analog DNA polymerase inhibitor480
Valproic acidAnti-epileptic agent421
VancomycinGlycopeptide antibacterial442
Vincristine380
VoriconazoleAzole antifungal495
ZidovudineHuman immunodeficiency virus nucleoside analog reverse transcriptase inhibitor637

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 46 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 Drug resistance name, in order of name
ClassReports with this term
Alkylating drug1,206
Aminoglycoside antibacterial877
Anthracycline topoisomerase inhibitor475
Anti-epileptic agent1,816
Antimalarial293
Antimetabolite immunosuppressant740
Antimycobacterial896
Atypical antipsychotic1,267
Azole antifungal1,202
Benzodiazepine905
Calcineurin inhibitor immunosuppressant1,117
CD20-directed cytolytic antibody834
Cephalosporin antibacterial631
Corticosteroid2,756
Cytochrome P450 3A inhibitor759
Cytomegalovirus nucleoside analog DNA polymerase inhibitor1,207
Dihydrofolate reductase inhibitor antibacterial280
Fluoroquinolone antibacterial1,320
Folate analog metabolic inhibitor951
Glycopeptide antibacterial512
Hepatitis B virus nucleoside analog reverse transcriptase inhibitor3,279
Herpes simplex virus nucleoside analog DNA polymerase inhibitor404
Human immunodeficiency virus 1 Non-Nucleoside analog reverse transcriptase inhibitor2,115
Human immunodeficiency virus integrase strand transfer inhibitor341
Human immunodeficiency virus nucleoside analog reverse transcriptase inhibitor1,656
Kinase inhibitor6,259
Lipid-based polyene antifungal250
Macrolide antimicrobial616
Microtubule inhibitor428
Mood stabilizer510
Nonsteroidal anti-inflammatory drug347
Nucleoside metabolic inhibitor1,175
Oxazolidinone antibacterial635
P2Y12 platelet inhibitor451
Penem antibacterial671
Penicillin-class antibacterial384
Platinum-based drug1,064
Protease inhibitor536
Proteasome inhibitor267
Pyrophosphate analog DNA polymerase inhibitor341
Rifamycin antibacterial403
Serotonin reuptake inhibitor259
Tetracycline-class drug294
Topoisomerase inhibitor506
Tumor necrosis factor blocker1,118
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 Drug resistance, 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 Drug resistance
AgeReportsShareShare as a bar
Under 23761.5%
2 to 118243.3%
12 to 175372.1%
18 to 444,37417.3%
45 to 645,87023.2%
65 to 742,53510%
75 and over1,3285.2%
Age not given9,48237.4%
Sex of the patient in the reports that record Drug resistance
SexReportsShareShare as a bar
Female9,49537.5%
Male10,26240.5%
Unknown or not given5,56922%

Age and sex are as the report gives them. 29.3% of these reports give the United States as the country.

Terms near this one

Official pages

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

Cite this page

Embed this card on your site

Copy this code into your page. The card shows the figures above with their source. A line under the card links to this page.

How embedding works. It is free. Keep the link in the card and the link line under it.

Reported Reactions. Drug resistance: adverse event reports that record this term. https://reportedreactions.com/reaction/drug-resistance/ 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 Drug resistance mean in an adverse event report?

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 .