Reported Reactions

Adverse event reports that FDA received

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Electrocardiogram QRS complex prolonged 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 5,033 adverse event reports that record the MedDRA preferred term Electrocardiogram QRS complex prolonged. The person who codes a report selects the term that agrees best with the description of the reporter.

FDA received 483 reports in the 12 months to June 2026 and 332 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 1,004 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, 483 (under 0.1%) record this term. Reports for patients aged 18 to 44 were 32.6% of the reports that record this term and 12.3% 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 95 drug pages with 25 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 Electrocardiogram QRS complex prolonged name as a suspect product, in order of name
DrugClassReports with this term
Acetaminophen141
Alcohol75
AlprazolamBenzodiazepine105
Amiodarone65
Amitriptyline254
Amitriptyline hclTricyclic antidepressant38
Amitriptyline hydrochlorideTricyclic antidepressant35
AmlodipineCalcium channel blocker130
AripiprazoleAtypical antipsychotic84
AspirinNonsteroidal anti-inflammatory drug48
Atenololbeta-Adrenergic blocker39
Atorvastatin69
Baclofengamma-Aminobutyric acid-ergic agonist41
Benzonatate30
Bisoprololbeta-Adrenergic blocker30
Bromazepam33
BupropionAminoketone443
Bupropion hydrochlorideAminoketone225
Bupropion Hydrochloride XLAminoketone25
Buspirone30
Calcium26
CarbamazepineMood stabilizer51
Carvedilolalpha-Adrenergic blocker33
CitalopramSerotonin reuptake inhibitor133
Citalopram hydrobromideSerotonin reuptake inhibitor70
ClobazamBenzodiazepine34
ClonazepamBenzodiazepine111
ClonidineCentral alpha-2 adrenergic agonist28
CyclobenzaprineMuscle relaxant44
DiazepamBenzodiazepine73
DigoxinCardiac glycoside85
Diltiazem43
DiphenhydramineHistamine-1 receptor antagonist64
Diphenhydramine hydrochlorideHistamine-1 receptor antagonist37
DoxepinTricyclic antidepressant47
Enalapril maleateAngiotensin converting enzyme inhibitor26
EpinephrineCatecholamine46
EscitalopramSerotonin reuptake inhibitor170
Flecainide320
Flecainide acetateAntiarrhythmic110
FluoxetineSerotonin reuptake inhibitor151
Fluoxetine hydrochlorideSerotonin reuptake inhibitor39
FurosemideLoop diuretic62
GabapentinAnti-epileptic agent104
HydrochlorothiazideThiazide diuretic47
HydroxychloroquineAntimalarial110
Hydroxychloroquine sulfateAntimalarial28
HydroxyzineAntihistamine49
IbuprofenNonsteroidal anti-inflammatory drug120
Lacosamide177
LamotrigineAnti-epileptic agent296
Levetiracetam99
Levothyroxine33
LidocaineAmide local anesthetic55
LisinoprilAngiotensin converting enzyme inhibitor59
Loperamide126
Loperamide hydrochlorideOpioid agonist51
LorazepamBenzodiazepine129
Melatonin25
MetforminBiguanide86
Metoprololbeta-Adrenergic blocker64
MidazolamBenzodiazepine28
Mirtazapine55
NorepinephrineCatecholamine55
Nortriptyline63
OlanzapineAtypical antipsychotic101
OxcarbazepineAnti-epileptic agent46
OxycodoneOpioid agonist60
PantoprazoleProton pump inhibitor34
Paracetamol40
Phenobarbital34
Potassium chlorideOsmotic laxative29
PrednisoneCorticosteroid29
Pregabalin32
PropafenoneAntiarrhythmic112
Propafenone hydrochlorideAntiarrhythmic44
PropofolGeneral anesthetic60
Propranololbeta-Adrenergic blocker107
Propranolol hydrochloridebeta-Adrenergic blocker41
QuetiapineAtypical antipsychotic196
Quetiapine fumarateAtypical antipsychotic81
RamiprilAngiotensin converting enzyme inhibitor48
RisperidoneAtypical antipsychotic40
RosuvastatinHMG-CoA reductase inhibitor29
SertralineSerotonin reuptake inhibitor37
Sodium bicarbonateOsmotic laxative75
SpironolactoneAldosterone antagonist66
Tramadol29
Trazodone84
Vasopressin28
VenlafaxineSerotonin and norepinephrine reuptake inhibitor152
Venlafaxine hydrochlorideSerotonin and norepinephrine reuptake inhibitor62
Verapamil39
Zolpidemgamma-Aminobutyric acid A receptor positive modulator37
Zopiclone29

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 54 pharmacologic classes with 10 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 Electrocardiogram QRS complex prolonged name, in order of name
ClassReports with this term
Aldosterone antagonist82
alpha-Adrenergic blocker44
Amide local anesthetic63
Aminoketone720
Angiotensin 2 receptor blocker55
Angiotensin converting enzyme inhibitor160
Anti-epileptic agent530
Antiarrhythmic308
Anticholinergic14
Antihistamine49
Antimalarial148
Aromatic amino acid10
Atypical antipsychotic552
Benzodiazepine533
beta-Adrenergic blocker336
beta2-Adrenergic agonist10
Biguanide123
Bisphosphonate10
Calcium channel blocker159
Cardiac glycoside87
Catecholamine113
Central alpha-2 adrenergic agonist55
Central nervous system stimulant44
Corticosteroid46
Dihydrofolate reductase inhibitor antibacterial12
Dihydropyridine calcium channel blocker16
Factor Xa inhibitor14
Fluoroquinolone antibacterial14
Folate analog metabolic inhibitor11
gamma-Aminobutyric acid A receptor positive modulator41
gamma-Aminobutyric acid-ergic agonist41
General anesthetic69
Histamine-1 receptor antagonist125
Histamine-2 receptor antagonist18
HMG-CoA reductase inhibitor58
Insulin analog16
l-Thyroxine23
Loop diuretic80
Mood stabilizer79
Muscle relaxant69
Nitrate vasodilator23
Nondepolarizing neuromuscular blocker13
Nonsteroidal anti-inflammatory drug228
Opioid agonist245
Osmotic laxative109
Proton pump inhibitor67
Serotonin and norepinephrine reuptake inhibitor245
Serotonin reuptake inhibitor665
Serotonin-1b and Serotonin-1d receptor agonist11
Serotonin-3 receptor antagonist21
Sigma-1 agonist14
Sphingosine 1-phosphate receptor modulator19
Thiazide diuretic47
Tricyclic antidepressant156

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

Reports by month

Reports that record Electrocardiogram QRS complex prolonged, by month, five years to June 2026
05010020222023202420252026

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 Electrocardiogram QRS complex prolonged
AgeReportsShareShare as a bar
Under 2851.7%
2 to 11671.3%
12 to 174038%
18 to 441,64032.6%
45 to 641,13222.5%
65 to 744308.5%
75 and over4589.1%
Age not given81816.3%
Sex of the patient in the reports that record Electrocardiogram QRS complex prolonged
SexReportsShareShare as a bar
Female2,35646.8%
Male1,90237.8%
Unknown or not given77515.4%

Age and sex are as the report gives them. 59.9% 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

Reported Reactions. Electrocardiogram QRS complex prolonged: adverse event reports that record this term. https://reportedreactions.com/reaction/electrocardiogram-qrs-complex-prolonged/ 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 Electrocardiogram QRS complex prolonged 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 .