78/100 · Elevated
Manufactured by Apotex Corp.
Tizanidine Adverse Events Show High Incidence of Serious Reactions
50,594 FDA adverse event reports analyzed
Last updated: 2026-05-12
TIZANIDINE is a medication tracked in the FDA Adverse Event Reporting System (FAERS), manufactured by Apotex Corp.. Based on analysis of 50,594 FDA adverse event reports, TIZANIDINE has a safety score of 78 out of 100. This score indicates a relatively favorable safety profile, with fewer or less severe adverse events compared to many other tracked medications. The most commonly reported adverse reactions for TIZANIDINE include FATIGUE, PAIN, DRUG INEFFECTIVE, NAUSEA, FALL. This page provides a comprehensive breakdown of reported side effects, safety signals, patient demographics, and AI-powered safety analysis for TIZANIDINE.
Tizanidine has a safety concern score of 78 out of 100, placing it in the high concern category based on analysis of FDA adverse event data. The FDA has received approximately 50,594 adverse event reports for this medication, which is primarily manufactured by Apotex Corp..
The most commonly reported adverse events include Fatigue, Pain, Drug Ineffective. Of classified reports, 61.4% were designated as serious by the FDA, meaning they involved hospitalization, disability, or other significant medical outcomes. Tizanidine reports include a high number of serious adverse events, particularly falls and kidney issues.
The most common reactions are fatigue, pain, and drug ineffectiveness, indicating potential efficacy concerns. Multiple sclerosis relapse and pneumonia are notable among chronic conditions affected by the drug. Overdose and death are reported, highlighting the need for strict dosing and monitoring.
Patients taking Tizanidine should monitor for the commonly reported side effects and contact their healthcare provider if they experience any unusual symptoms. Tizanidine can cause falls and kidney issues, and there are warnings about drug interactions, particularly with other sedatives and antihypertensives. This analysis is based on voluntary FDA adverse event reports and should not replace professional medical advice.
Tizanidine received a safety concern score of 78/100 (high concern). This is based on a 61.4% serious event ratio across 22,745 classified reports. The score accounts for 50,594 total adverse event reports and 100 distinct reaction types. This high score reflects a significant proportion of serious adverse events in the reporting data.
Adverse event reports by sex: Female: 15,795, Male: 5,288, Unknown: 34. The most frequently reported age groups are age 64 (534 reports), age 56 (441 reports), age 58 (437 reports). These demographics reflect reporting patterns and may not represent the full patient population.
Out of 22,745 classified reports for TIZANIDINE:
The FDA classifies an adverse event as “serious” if it results in death, hospitalization, disability, congenital anomaly, or requires intervention to prevent permanent damage.
Demographics reflect voluntary FDA adverse event reporting patterns and may not represent the full patient population.
Tizanidine can cause falls and kidney issues, and there are warnings about drug interactions, particularly with other sedatives and antihypertensives.
If you are taking Tizanidine, here are important things to know. The most commonly reported side effects include fatigue, pain, drug ineffective, nausea, fall. While many of these may be mild and temporary, you should contact your healthcare provider if any symptoms are severe or persistent. Patients should avoid driving or operating heavy machinery due to the risk of falls and dizziness. Regular monitoring of kidney function is advised, especially in patients with pre-existing kidney conditions. If you experience a serious adverse reaction, seek emergency medical attention immediately or call 911. You can report side effects to the FDA's MedWatch program at 1-800-FDA-1088.
Regulators have issued warnings about the serious risks associated with tizanidine, including falls and kidney injury, and recommend close monitoring of patients.
The FDA has received approximately 50,594 adverse event reports associated with Tizanidine. These reports come from healthcare professionals, consumers, and manufacturers through the FDA Adverse Event Reporting System (FAERS). Note that the number of reports does not directly indicate the frequency of side effects, as adverse events are voluntarily reported and may be underrepresented.
The most frequently reported adverse events for Tizanidine include Fatigue, Pain, Drug Ineffective, Nausea, Fall. By volume, the top reported reactions are: Fatigue (1,693 reports), Pain (1,615 reports), Drug Ineffective (1,572 reports). These figures reflect FDA adverse event reports and may not represent the true incidence rate of these side effects in all patients taking Tizanidine.
Out of 22,745 classified reports, 13,962 (61.4%) were classified as serious and 8,783 as non-serious. The FDA classifies an event as "serious" if it results in death, hospitalization, disability, or other medically significant outcomes. A higher serious-event ratio warrants closer attention but does not necessarily mean the drug is unsafe.
Adverse event reports for Tizanidine break down by patient sex as follows: Female: 15,795, Male: 5,288, Unknown: 34. This distribution reflects reporting patterns rather than actual risk differences between groups. Reporting rates can be influenced by prescribing patterns, disease demographics, and reporting behavior.
The most frequently reported age groups for Tizanidine adverse events are: age 64: 534 reports, age 56: 441 reports, age 58: 437 reports, age 57: 435 reports, age 59: 435 reports. Age-related reporting patterns can reflect both the demographics of the patient population and potential age-related susceptibility to certain side effects.
The primary manufacturer associated with Tizanidine adverse event reports is Apotex Corp.. Multiple manufacturers may produce generic versions of this drug. The manufacturer listed reflects the most frequently reported brand in FDA adverse event data.
Beyond the most common reactions, other reported adverse events for Tizanidine include: Headache, Chronic Kidney Disease, Diarrhoea, Dizziness, Off Label Use. Less common side effects can still be clinically significant. Patients should report any unusual symptoms to their healthcare provider.
You can report adverse events from Tizanidine to the FDA through their MedWatch program at www.fda.gov/medwatch, by calling 1-800-FDA-1088, or by completing Form FDA 3500. Healthcare professionals, consumers, and manufacturers can all submit reports. Reporting helps the FDA monitor drug safety after approval.
Tizanidine has a safety concern score of 78 out of 100 (high concern). This score is calculated from the ratio of serious to non-serious adverse events, the diversity of reported reactions, and the overall volume of reports relative to usage. Tizanidine reports include a high number of serious adverse events, particularly falls and kidney issues.
Key safety signals identified in Tizanidine's adverse event data include: Falls and acute kidney injury are key safety signals, indicating potential risks for falls and kidney damage.. Multiple sclerosis relapse and pneumonia suggest the drug may exacerbate these conditions.. Overdose and death reports are critical safety signals, emphasizing the need for careful dosing and patient monitoring.. These signals are derived from patterns in FDA reports and should be discussed with a healthcare provider for personalized assessment.
Tizanidine can cause falls and kidney issues, and there are warnings about drug interactions, particularly with other sedatives and antihypertensives. Always inform your healthcare provider about all medications, supplements, and over-the-counter drugs you are taking before starting Tizanidine.
Patients should avoid driving or operating heavy machinery due to the risk of falls and dizziness. Regular monitoring of kidney function is advised, especially in patients with pre-existing kidney conditions.
Tizanidine has 50,594 adverse event reports on file with the FDA. The most common reactions are fatigue, pain, and drug ineffectiveness, indicating potential efficacy concerns. The volume of reports for Tizanidine reflects both the drug's usage level and the vigilance of the reporting community.
Regulators have issued warnings about the serious risks associated with tizanidine, including falls and kidney injury, and recommend close monitoring of patients. For the most current regulatory information, check the FDA's drug labeling database or consult your pharmacist.
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