Reported Reactions

Adverse event reports that FDA received

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Cefaclor adverse event reports that FDA received

Name type
Generic name
Class
Cephalosporin antibacterial
Also reported as
Cefaclor Extended-Release Tablets

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 February 2004 to June 2026, FDA received 729 adverse event reports that name Cefaclor. In these reports the drug is a suspect or interacting product.

In the same period, 829 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 38 reports in the 12 months to June 2026 and 39 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, 38 (under 0.1%) name Cefaclor. Reports from consumers or other non-health professionals were 16.5% of the reports that name Cefaclor and 45.8% 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 Cefaclor 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 9 reports that name Cefaclor.
  • In January to March 2026, FDA received 13.
  • In April to June 2025, FDA received 9.

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 130 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 709 of the 729 reports (97.3%).

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 130 terms.

Reaction terms in the reports that name Cefaclor, most reports first
Reaction term (MedDRA) and plain meaningReportsShare of the 729 reports
Drug hypersensitivityan allergic-type reaction (the term names a medicine)24433.5%
Vomitingbeing sick11615.9%
Nauseafeeling sick10915%
Fatiguetiredness9312.8%
Drug intolerancethe medicine was not tolerated9212.6%
Infectionan infection, type not specified8912.2%
International normalised ratio fluctuation8812.1%
Therapeutic product effect incomplete8411.5%
Bloody discharge689.3%
Drug ineffectivethe medicine did not work as expected689.3%
Dizzinesslight-headedness or unsteadiness679.2%
Lyme disease679.2%
Urticariahives567.7%
Diarrhoealoose or frequent stools547.4%
Abdominal painstomach or belly pain527.1%
Dyspnoeashortness of breath517%
Rashskin rash517%
Hypersensitivityan allergic-type reaction496.7%
Malaisegeneral feeling of being unwell486.6%
Pruritusitching476.4%
Staphylococcal infection446%
Hypoaesthesianumbness415.6%
Iron deficiency415.6%
Platelet count increased415.6%
Rash erythematousa red rash405.5%
Pain in extremitypain in an arm or leg395.3%
Red blood cell sedimentation rate increased385.2%
Secretion discharge385.2%
Clostridium difficile infection354.8%
Angioedemadeep swelling of skin or mucous membranes344.7%
Headachehead pain344.7%
Dysphagiadifficulty swallowing334.5%
Toxic epidermal necrolysisa severe skin reaction with peeling314.3%
Pyrexiafever304.1%
Speech disordera speech problem304.1%
Dysphemia294%
Abdominal discomfortstomach discomfort263.6%
Anaphylactic reactiona severe, sudden allergic reaction263.6%
Dysphoniaa hoarse voice263.6%
Hypotensionlow blood pressure263.6%
Rash pruritican itchy rash253.4%
Cough243.3%
Inappropriate schedule of product administrationthe product was taken at the wrong times243.3%
Blood pressure increaseda raised blood pressure reading233.2%
Chest discomfort233.2%
Liver injury233.2%
Muscular weaknessmuscle weakness233.2%
Product dose omission issuea dose was missed233.2%
Dry eye223%
Eye inflammation223%

Download all 130 terms of Cefaclor (CSV)

The counts add to more than 729 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.

Outcomes by year

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

Outcomes in the reports that name Cefaclor, 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
20044039342312111
20053131051820110
200614132360031
200713131182050
20081090041061
200910100341060
2010131300100040
20112524011000171
20122926101411143
20133733452602124
20143633031920153
2015241500900119
201638191011101219
201716401300212
20182918005001411
20195817215101241
20203924808401415
20214138111660313
20226254011670508
20233830011540278
20243427001430247
202552494834210433
2026403681421130344

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 Cefaclor, by the year in which FDA received them
050100200420082012201620202024

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 Cefaclor, by the year in which FDA received them
YearReports
200434
200534
200615
200715
20089
200910
201012
201128
201232
201338
201436
201526
201647
201718
201856
201967
202035
202150
202247
202328
202434
202536
202622
Reports that name Cefaclor, by month, five years to June 2026
051020222023202420252026

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 Cefaclor
AgeReportsShareShare as a bar
Under 2375.1%
2 to 11527.1%
12 to 17141.9%
18 to 4411315.5%
45 to 6418425.2%
65 to 74557.5%
75 and over446%
Age not given23031.6%
Sex of the patient in the reports that name Cefaclor
SexReportsShareShare as a bar
Female41657.1%
Male18225%
Unknown or not given13118%
Type of reporter in the reports that name Cefaclor
ReporterReportsShareShare as a bar
Physician22330.6%
Pharmacist233.2%
Other health professional32144%
Lawyer00%
Consumer or non-health professional12016.5%
Not given425.8%

Age and sex are as the report gives them. The reporter is the primary source in the report. 25.2% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Cefaclor record
Indication as recorded (MedDRA)ReportsShare
Upper respiratory tract infection152.1%
Cystitis141.9%
Rheumatoid arthritis121.6%
Urinary tract infection111.5%
Infection prophylaxis101.4%
Oral candidiasis71%

The reporter fills in the indication, and the field is often empty. Each share is of all 729 reports.

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

Reported Reactions. Cefaclor: adverse event reports that FDA received. https://reportedreactions.com/drug/cefaclor/ 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 Cefaclor as a suspect or interacting product. The 829 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 Cefaclor 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 Cefaclor?

No. It is a count of what people reported to FDA: 729 reports from February 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%), physician (30.6%) and consumer or non-health professional (16.5%). 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.