Tizanidine hydrochloride adverse event reports that FDA received

Name: Reaction terms in FDA adverse event reports that name Tizanidine hydrochloride
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 Hydrochloride Tablets, Tizanidine Hcl 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 1,051 adverse event reports that name Tizanidine hydrochloride. In these reports the drug is a suspect or interacting product.

In the same period, 5,818 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 104 reports in the 12 months to June 2026 and 60 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, 104 (under 0.1%) name Tizanidine hydrochloride. Reports from consumers or other non-health professionals were 23.6% of the reports that name Tizanidine hydrochloride 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 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 hydrochloride 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 10 reports that name Tizanidine hydrochloride.
In January to March 2026, FDA received 32.
In April to June 2025, FDA received 14.

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 103 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 1,000 of the 1,051 reports (95.1%).

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 103 terms.

Reaction terms in the reports that name Tizanidine hydrochloride, most reports first
Reaction term (MedDRA) and plain meaning	Reports	Share of the 1,051 reports
Somnolencedrowsiness	228	21.7%
Gastrooesophageal reflux diseaseacid reflux	190	18.1%
Coma	189	18%
Pneumonia aspirationlung infection from breathing in material	185	17.6%
Completed suicidedeath by suicide	157	14.9%
Toxicity to various agentspoisoning or toxic effect of one or more substances	96	9.1%
Hypotensionlow blood pressure	70	6.7%
Drug ineffectivethe medicine did not work as expected	67	6.4%
Drug interactionan interaction between medicines	54	5.1%
Underdoseless than the intended dose	46	4.4%
Off label useused for a purpose or in a way not on the label	38	3.6%
Dizzinesslight-headedness or unsteadiness	35	3.3%
Bradycardiaslow heart rate	33	3.1%
Intentional overdosea deliberate overdose	33	3.1%
Product quality issuea problem with the product itself	29	2.8%
Cardio-respiratory arrestthe heart and breathing stopped	25	2.4%
Depressed level of consciousness	23	2.2%
Overdosea dose above the recommended amount	23	2.2%
Tachycardiafast heart rate	21	2%
Confusional stateconfusion	19	1.8%
Fatiguetiredness	19	1.8%
Hypertensionhigh blood pressure	19	1.8%
Muscular weaknessmuscle weakness	18	1.7%
Vomitingbeing sick	18	1.7%
Acute kidney injurysudden loss of kidney function	17	1.6%
Sinus bradycardia	17	1.6%
Dry mouth	16	1.5%
Loss of consciousnesspassing out	16	1.5%
Malaisegeneral feeling of being unwell	16	1.5%
Mental status changes	16	1.5%
Nauseafeeling sick	16	1.5%
Incorrect route of product administrationthe product was given by the wrong route	15	1.4%
Insomniadifficulty sleeping	15	1.4%
Muscle spasmsmuscle cramps	15	1.4%
Product use in unapproved indicationused for a purpose not on the label	15	1.4%
Anxiety	14	1.3%
Drug withdrawal syndromesymptoms on stopping a medicine	14	1.3%
Hyperhidrosisexcessive sweating	14	1.3%
Intentional product misusedeliberate use not as intended	14	1.3%
Painpain, site not specified	14	1.3%
Dysarthria	13	1.2%
Electrocardiogram QT prolongeda QT prolongation on the ECG	13	1.2%
Hallucinationseeing or hearing things that are not there	13	1.2%
Condition aggravatedthe condition being treated got worse	12	1.1%
Headachehead pain	12	1.1%
Serotonin syndrometoo much serotonin activity, with agitation, fever and tremor	12	1.1%
Withdrawal syndrome	12	1.1%
Drug hypersensitivityan allergic-type reaction (the term names a medicine)	11	1%
Pain in extremitypain in an arm or leg	11	1%
Sedationdrowsiness	11	1%

Download all 103 terms of Tizanidine hydrochloride (CSV)

The counts add to more than 1,051 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	Generic name	4,259
Tizanidine hydrochloride (this page)	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 hydrochloride, 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	7	7	3	0	5	0	0	2	0
2005	1	1	0	0	1	0	0	0	0
2006	2	1	1	0	1	0	0	0	1
2007	3	3	2	0	1	0	0	0	0
2008	8	7	1	0	0	0	0	6	1
2009	22	22	1	3	8	1	1	18	0
2010	11	10	3	0	2	1	0	7	1
2011	36	28	3	2	15	0	0	13	8
2012	28	26	7	1	7	1	0	15	2
2013	22	15	2	1	12	2	0	10	7
2014	13	8	2	0	5	0	0	3	5
2015	43	33	11	6	11	0	0	14	10
2016	33	19	0	1	8	1	0	11	14
2017	35	19	12	0	12	1	0	8	16
2018	47	32	3	1	16	4	0	22	15
2019	117	94	18	1	70	1	1	63	23
2020	105	96	31	0	57	1	0	62	9
2021	95	88	27	6	50	0	0	57	7
2022	107	89	16	5	54	3	0	57	18
2023	81	54	8	2	36	1	1	38	27
2024	82	65	13	5	38	2	0	41	17
2025	111	94	51	26	47	0	0	58	17
2026	42	33	16	2	12	1	3	6	9

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 hydrochloride, 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 hydrochloride, by the year in which FDA received them
Year	Reports
2004	5
2005	2
2006	3
2007	2
2008	8
2009	22
2010	9
2011	33
2012	36
2013	20
2014	20
2015	52
2016	39
2017	36
2018	57
2019	122
2020	104
2021	110
2022	80
2023	72
2024	75
2025	102
2026	42

Reports that name Tizanidine hydrochloride, 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 hydrochloride
Age	Reports	Share
Under 2	4	0.4%
2 to 11	11	1%
12 to 17	8	0.8%
18 to 44	174	16.6%
45 to 64	389	37%
65 to 74	101	9.6%
75 and over	55	5.2%
Age not given	309	29.4%

Sex of the patient in the reports that name Tizanidine hydrochloride
Sex	Reports	Share
Female	657	62.5%
Male	234	22.3%
Unknown or not given	160	15.2%

Type of reporter in the reports that name Tizanidine hydrochloride
Reporter	Reports	Share
Physician	228	21.7%
Pharmacist	103	9.8%
Other health professional	441	42%
Lawyer	6	0.6%
Consumer or non-health professional	248	23.6%
Not given	25	2.4%

Age and sex are as the report gives them. The reporter is the primary source in the report. 66.6% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Tizanidine hydrochloride record
Indication as recorded (MedDRA)	Reports	Share
Muscle spasms	61	5.8%
Back pain	29	2.8%
Pain	28	2.7%
Muscle spasticity	11	1%
Muscle relaxant therapy	6	0.6%
Neck pain	6	0.6%

The reporter fills in the indication, and the field is often empty. Each share is of all 1,051 reports.

Drugs in the same reports

Other drugs that the reports of Tizanidine hydrochloride name, in any role, in order of name
Drug	Reports that name the two
Ativan	177
Baclofen	221
Docusate sodium	181
Ergocalciferol	182
Furosemide	174
Lyrica	190
Potassium chloride	183
Prednisone	206
Zantac	178
Zopiclone	177

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 same ingredient
Zanaflex same ingredient
Tizanidine hcl same class
Precedex same class
TNKase next in the A to Z list
Tobi next in the A to Z list
Tivicay next in the A to Z list
TOBI Podhaler next in the A to Z list
Tivdak next in the A to Z list
TobraDex next in the A to Z list
Tisseel next in the A to Z list
Tobramycin 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 Tizanidine hydrochlorideThe 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 hydrochloride: adverse event reports that FDA received. https://reportedreactions.com/drug/tizanidine-hydrochloride/ 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 hydrochloride as a suspect or interacting product. The 5,818 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 hydrochloride 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 hydrochloride?

No. It is a count of what people reported to FDA: 1,051 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?

Other health professional (42%), consumer or non-health professional (23.6%) and physician (21.7%). 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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