Dilantin (extended phenytoin sodium) adverse event reports that FDA received

Name: Reaction terms in FDA adverse event reports that name Dilantin
Creator: Reported Reactions
License: https://creativecommons.org/publicdomain/zero/1.0/

Name type: Brand name
Generic name: Extended phenytoin sodium
Class: Anti-epileptic agent
Also reported as: Dilantin Inj, Dilantin /00017401/, Dilantin Suspension

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 2 Oct 2026. The data have the reports that FDA received through 30 Jun 2026.

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 2 Oct 2026.

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 2 Oct 2026.

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 30 Jun 2026. Device reports have a separate cutoff, 30 Sep 2026. Why a report count is not a rate.

Reports on file

From January 2004 to June 2026, FDA received 8,011 adverse event reports that name Dilantin. In these reports the drug is a suspect or interacting product.

In the same period, 8,601 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 78 reports in the 12 months to June 2026 and 78 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, 78 (under 0.1%) name Dilantin. Reports from other health professionals were 13.7% of the reports that name Dilantin and 19.7% 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 11 Mar 2026. The site read the page on 2 Oct 2026.

Suspect product

FDA records each drug in a report as suspect, concomitant or interacting. This page counts the reports in which Dilantin 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 2 Oct 2026.

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 2 Oct 2026.

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 11 Mar 2026. The site read the page on 2 Oct 2026.

The latest update of the FDA data, recorded on 28 Oct 2026, changed no count of this page.

In April to June 2026, FDA received 4 reports that name Dilantin.
In January to March 2026, FDA received 18.
In April to June 2025, FDA received 15.

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 updates Feed 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 585 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 7,993 of the 8,011 reports (99.8%).

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.

Find a reaction term

The table shows the first 50 of 585 terms.

Reaction terms in the reports that name Dilantin, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 8,011 reports
Convulsion	1,312	16.4%
Drug hypersensitivityan allergic-type reaction (the term names a medicine)	770	9.6%
Seizurea fit or convulsion	719	9%
Drug ineffectivethe medicine did not work as expected	712	8.9%
Dizzinesslight-headedness or unsteadiness	434	5.4%
Stevens-Johnson syndromea severe skin and mucous-membrane reaction	429	5.4%
Drug interactionan interaction between medicines	398	5%
Falla fall	394	4.9%
Headachehead pain	334	4.2%
Anticonvulsant drug level decreased	316	3.9%
Rashskin rash	303	3.8%
Anticonvulsant drug level increased	291	3.6%
Fatiguetiredness	289	3.6%
Gait disturbancedifficulty walking	284	3.5%
Balance disorderproblems with balance	265	3.3%
Feeling abnormalfeeling odd or not right	259	3.2%
Toxicity to various agentspoisoning or toxic effect of one or more substances	259	3.2%
Tremorshaking	259	3.2%
Weight decreasedweight loss	234	2.9%
Nauseafeeling sick	233	2.9%
Somnolencedrowsiness	230	2.9%
Condition aggravatedthe condition being treated got worse	227	2.8%
Malaisegeneral feeling of being unwell	227	2.8%
Pharmaceutical product complaint	211	2.6%
Memory impairmentmemory problems	202	2.5%
Astheniaweakness or lack of energy	199	2.5%
Confusional stateconfusion	192	2.4%
Drug level decreaseda low blood level of the medicine	189	2.4%
Grand mal convulsion	180	2.2%
Painpain, site not specified	175	2.2%
Vomitingbeing sick	167	2.1%
Amnesiamemory loss	160	2%
Insomniadifficulty sleeping	158	2%
Pyrexiafever	154	1.9%
Cerebrovascular accidentstroke	153	1.9%
Depressionlow mood	153	1.9%
Pruritusitching	146	1.8%
Hypoaesthesianumbness	144	1.8%
Dysarthria	140	1.7%
Loss of consciousnesspassing out	138	1.7%
Drug level increaseda raised blood level of the medicine	130	1.6%
Off label useused for a purpose or in a way not on the label	127	1.6%
Ataxia	124	1.5%
Hypertensionhigh blood pressure	121	1.5%
Speech disordera speech problem	121	1.5%
Anxiety	120	1.5%
Weight increasedweight gain	120	1.5%
Anticonvulsant drug level below therapeutic	118	1.5%
Cerebellar atrophy	118	1.5%
Hypersensitivityan allergic-type reaction	118	1.5%

Download all 585 terms of Dilantin (CSV)

The counts add to more than 8,011 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 2 Oct 2026.

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 Dilantin, by the year of the openFDA file that holds the report

The table continues to the right.

Year of the openFDA file	Reports	Serious	Death	Life-threatening	Hospitalization (initial or prolonged)	Disability or Permanent Damage	Congenital Anomaly/Birth Defect	Other Serious (Important Medical Events)	Not serious
2004	335	314	18	17	125	14	2	229	21
2005	462	382	10	20	125	16	2	290	80
2006	300	289	14	12	113	22	5	221	11
2007	441	399	24	18	100	14	9	342	42
2008	563	479	26	27	132	11	6	408	84
2009	269	219	22	15	88	12	1	169	50
2010	311	266	18	12	115	12	1	200	45
2011	369	303	9	15	119	10	4	255	66
2012	434	342	18	6	137	22	0	285	92
2013	523	394	23	7	165	12	3	353	129
2014	402	253	19	8	99	7	3	198	149
2015	564	339	24	8	123	8	6	273	225
2016	454	237	26	5	95	5	1	176	217
2017	303	161	11	1	61	2	3	124	142
2018	348	146	15	5	52	6	0	110	202
2019	530	287	17	19	111	23	0	225	243
2020	566	365	20	7	112	11	0	310	201
2021	330	233	10	7	65	8	1	203	97
2022	172	90	7	3	26	6	0	79	82
2023	105	63	5	3	20	5	0	56	42
2024	78	58	1	1	30	0	0	40	20
2025	105	87	4	6	33	6	0	63	18
2026	47	36	2	4	15	5	0	31	11

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 2 Oct 2026.

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 2 Oct 2026.

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 Dilantin, by the year in which FDA received them

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 Dilantin, by the year in which FDA received them
Year	Reports
2004	316
2005	449
2006	320
2007	383
2008	495
2009	221
2010	405
2011	529
2012	558
2013	433
2014	437
2015	592
2016	465
2017	334
2018	400
2019	522
2020	481
2021	237
2022	141
2023	97
2024	70
2025	104
2026	22

Reports that name Dilantin, by month, five years to June 2026

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 Dilantin
Age	Reports	Share
Under 2	35	0.4%
2 to 11	118	1.5%
12 to 17	89	1.1%
18 to 44	1,068	13.3%
45 to 64	1,796	22.4%
65 to 74	749	9.3%
75 and over	446	5.6%
Age not given	3,710	46.3%

Sex of the patient in the reports that name Dilantin
Sex	Reports	Share
Female	4,120	51.4%
Male	3,206	40%
Unknown or not given	685	8.6%

Type of reporter in the reports that name Dilantin
Reporter	Reports	Share
Physician	1,676	20.9%
Pharmacist	700	8.7%
Other health professional	1,097	13.7%
Lawyer	424	5.3%
Consumer or non-health professional	3,548	44.3%
Not given	566	7.1%

Age and sex are as the report gives them. The reporter is the primary source in the report. 81.6% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Dilantin record
Indication as recorded (MedDRA)	Reports	Share
Convulsion	1,802	22.5%
Seizure	914	11.4%
Epilepsy	848	10.6%
Grand mal convulsion	150	1.9%
Ill-defined disorder	129	1.6%
Generalised tonic-clonic seizure	101	1.3%

The reporter fills in the indication, and the field is often empty. Each share is of all 8,011 reports.

Drugs in the same reports

Other drugs that the reports of Dilantin name, in any role, in order of name
Drug	Reports that name the two
Aspirin	221
Depakote	328
Keppra	659
Lamictal	304
Lisinopril	183
Neurontin	297
Phenobarbital	375
Phenytoin	303
Tegretol	337
Topamax	208

The table has the 10 drug names that these reports name most. Two names in one report says only that the report recorded the two. It says nothing about the part of a product in the event.

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 2 Oct 2026.

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 11 Mar 2026. The site read the page on 2 Oct 2026.

Pages near this one

Depakote same class
Dilantin-125 same class
Divalproex sodium same class
Divalproex sodium er same class
Dihydroergotamine mesylate next in the A to Z list
Dilantin Kapseal next in the A to Z list
Dihydroergotamine next in the A to Z list
Dihydrocodeine bitartrate next in the A to Z list
Dilatrend next in the A to Z list
Dihydrocodeine next in the A to Z list
Dilaudid next in the A to Z list
Digoxin next in the A to Z list

These links are for navigation. No count selected them. The class page lists each drug of the class.

Official pages

DailyMed labels for DilantinThe labels (prescribing information) that have this name, at the National Library of Medicine.
MedWatch Online Voluntary Reporting FormThe online form of FDA for a voluntary report.
MedWatch: The FDA Safety Information and Adverse Event Reporting ProgramThe page of the FDA program that receives reports about drugs and devices.
FDA Adverse Event Monitoring System (AEMS) Public DashboardThe public dashboard of FDA for adverse event reports on drugs and biologics.

The site checked these addresses on 2 Oct 2026. The links open in a new tab.

Cite this page

Reported Reactions. Dilantin: adverse event reports that FDA received. https://reportedreactions.com/drug/dilantin/ Source: U.S. Food and Drug Administration, openFDA Drug Adverse Event (FAERS) files, release of 29 Oct 2026. Reports received through 30 Jun 2026.

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 Dilantin as a suspect or interacting product. The 8,601 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 Dilantin 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 11 Mar 2026. The site read the page on 2 Oct 2026.

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 Dilantin?

No. It is a count of what people reported to FDA: 8,011 reports from January 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?

Consumer or non-health professional (44.3%), physician (20.9%) and other health professional (13.7%). 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 2 Oct 2026.

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.

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