Tizanidine adverse event reports that FDA received

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

Name type: Generic name
Class: Central alpha-2 adrenergic agonist
Also reported as: Tizanidine Tablets Usp, Tizanidine /00740702/, Tizanidine 4mg

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 September 2004 to June 2026, FDA received 4,259 adverse event reports that name Tizanidine. In these reports the drug is a suspect or interacting product.

In the same period, 20,656 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 376 reports in the 12 months to June 2026 and 192 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, 376 (under 0.1%) name Tizanidine. Reports for patients aged 45 to 64 were 36.7% of the reports that name Tizanidine and 20% 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 Tizanidine 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 80 reports that name Tizanidine.
In January to March 2026, FDA received 200.
In April to June 2025, FDA received 45.

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 404 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 4,224 of the 4,259 reports (99.2%).

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 404 terms.

Reaction terms in the reports that name Tizanidine, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 4,259 reports
Completed suicidedeath by suicide	621	14.6%
Toxicity to various agentspoisoning or toxic effect of one or more substances	407	9.6%
Drug ineffectivethe medicine did not work as expected	363	8.5%
Somnolencedrowsiness	362	8.5%
Hypotensionlow blood pressure	245	5.8%
Drug interactionan interaction between medicines	244	5.7%
Falla fall	239	5.6%
Fatiguetiredness	232	5.4%
Dizzinesslight-headedness or unsteadiness	216	5.1%
Coma	178	4.2%
Gait disturbancedifficulty walking	176	4.1%
Nauseafeeling sick	173	4.1%
Pneumonia aspirationlung infection from breathing in material	164	3.9%
Gastrooesophageal reflux diseaseacid reflux	162	3.8%
Drug hypersensitivityan allergic-type reaction (the term names a medicine)	150	3.5%
Painpain, site not specified	149	3.5%
Suspected suicide	138	3.2%
Headachehead pain	136	3.2%
Astheniaweakness or lack of energy	135	3.2%
Muscle spasmsmuscle cramps	134	3.1%
Cardio-respiratory arrestthe heart and breathing stopped	127	3%
Therapy cessation	123	2.9%
Condition aggravatedthe condition being treated got worse	121	2.8%
Deaththe patient died; cause not stated by this term	118	2.8%
Off label useused for a purpose or in a way not on the label	118	2.8%
Urinary tract infectionbladder or urinary infection	117	2.7%
Multiple sclerosis relapsea flare of multiple sclerosis	115	2.7%
Vomitingbeing sick	114	2.7%
Insomniadifficulty sleeping	109	2.6%
Overdosea dose above the recommended amount	106	2.5%
Balance disorderproblems with balance	100	2.3%
Cardiac arrestthe heart stopped	99	2.3%
Hypertensionhigh blood pressure	99	2.3%
Diarrhoealoose or frequent stools	98	2.3%
Memory impairmentmemory problems	98	2.3%
Confusional stateconfusion	97	2.3%
Muscular weaknessmuscle weakness	96	2.3%
Bradycardiaslow heart rate	95	2.2%
Depressionlow mood	94	2.2%
Malaisegeneral feeling of being unwell	91	2.1%
Tremorshaking	88	2.1%
Respiratory arrestbreathing stopped	87	2%
Back pain	85	2%
Pain in extremitypain in an arm or leg	84	2%
Dyspnoeashortness of breath	80	1.9%
Loss of consciousnesspassing out	75	1.8%
Drug withdrawal syndromesymptoms on stopping a medicine	72	1.7%
Feeling abnormalfeeling odd or not right	67	1.6%
Intentional overdosea deliberate overdose	66	1.5%
Seizurea fit or convulsion	64	1.5%

Download all 404 terms of Tizanidine (CSV)

The counts add to more than 4,259 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.

Same ingredient, other names

Reporters write a brand name or a generic name. Each name has its own page and its own count.

Names of Tizanidine with a page, in the order generic names, brand names, names as reported
Name	Name type	Reports
Tizanidine (this page)	Generic name	4,259
Tizanidine hydrochloride	Generic name	1,051
Zanaflex	Brand name	1,166

Sum of the separately reported names: 6,476. A report that names two of these names is in the sum two times. The sum is not the number of reports for the ingredient.

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.

Outcomes by year

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

Outcomes in the reports that name Tizanidine, 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	8	8	4	3	3	0	0	3	0
2005	4	4	1	0	2	0	0	3	0
2006	2	2	0	1	1	1	0	0	0
2007	2	2	0	1	0	0	0	1	0
2009	1	1	0	0	1	0	0	0	0
2010	19	19	12	0	2	3	0	6	0
2011	35	35	28	1	4	0	0	5	0
2012	21	15	1	2	6	0	0	7	6
2013	118	104	56	4	26	3	0	35	14
2014	181	130	12	5	54	9	0	87	51
2015	338	217	96	13	69	8	0	92	121
2016	409	202	49	2	89	11	0	116	207
2017	362	189	76	3	80	9	0	100	173
2018	460	190	42	10	103	13	0	88	270
2019	352	215	75	10	127	6	0	106	137
2020	303	253	100	13	129	4	7	128	50
2021	350	294	134	7	138	6	1	156	56
2022	281	256	98	16	121	5	2	169	25
2023	269	203	55	12	93	2	0	145	66
2024	206	169	59	10	86	3	0	119	37
2025	250	207	67	26	102	2	1	143	43
2026	288	258	152	14	105	1	3	175	30

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 Tizanidine, 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 Tizanidine, by the year in which FDA received them
Year	Reports
2004	8
2005	4
2006	2
2007	2
2009	1
2010	14
2011	43
2012	25
2013	121
2014	225
2015	371
2016	423
2017	398
2018	448
2019	312
2020	315
2021	345
2022	250
2023	244
2024	197
2025	231
2026	280

Reports that name Tizanidine, 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 Tizanidine
Age	Reports	Share
Under 2	13	0.3%
2 to 11	21	0.5%
12 to 17	36	0.8%
18 to 44	853	20%
45 to 64	1,563	36.7%
65 to 74	440	10.3%
75 and over	173	4.1%
Age not given	1,160	27.2%

Sex of the patient in the reports that name Tizanidine
Sex	Reports	Share
Female	2,821	66.2%
Male	1,098	25.8%
Unknown or not given	340	8%

Type of reporter in the reports that name Tizanidine
Reporter	Reports	Share
Physician	1,194	28%
Pharmacist	303	7.1%
Other health professional	1,073	25.2%
Lawyer	6	0.1%
Consumer or non-health professional	1,562	36.7%
Not given	121	2.8%

Age and sex are as the report gives them. The reporter is the primary source in the report. 83.7% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Tizanidine record
Indication as recorded (MedDRA)	Reports	Share
Muscle spasms	229	5.4%
Back pain	97	2.3%
Muscle spasticity	83	1.9%
Pain	73	1.7%
Suicide attempt	64	1.5%
Muscle relaxant therapy	63	1.5%

The reporter fills in the indication, and the field is often empty. Each share is of all 4,259 reports.

Drugs in the same reports

Other drugs that the reports of Tizanidine name, in any role, in order of name
Drug	Reports that name the two
Alprazolam	235
Ampyra	874
Baclofen	815
Clonazepam	372
Cymbalta	256
Duloxetine	262
Ergocalciferol	302
Gabapentin	827
Lyrica	326
Tramadol	257

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

Tizanidine hydrochloride same ingredient
Zanaflex same ingredient
Precedex same class
Tizanidine hcl same class
Methyldopa same class
Intuniv same class
Tivicay next in the A to Z list
Tivdak next in the A to Z list
Tisseel next in the A to Z list
TNKase next in the A to Z list
Tislelizumab next in the A to Z list
Tobi 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 TizanidineThe 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. Tizanidine: adverse event reports that FDA received. https://reportedreactions.com/drug/tizanidine/ 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 Tizanidine as a suspect or interacting product. The 20,656 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 Tizanidine 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 Tizanidine?

No. It is a count of what people reported to FDA: 4,259 reports from September 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 (36.7%), physician (28%) and other health professional (25.2%). 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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