Tizanidine 4mg tablets
Requires a prescription from a doctor or prescriber
Tizanidine is a fast-acting drug used for the management of muscle spasm, which may result from the effects of multiple sclerosis, stroke, an acquired brain injury, or a spinal cord injury [T574].
Safety information for pregnancy and breastfeeding
Pregnancy
Oral LD50 (rat): 414 mg/kg; Subcutaneous LD50 (rat): 282 mg/kg; Oral LD50 (mouse): 235 mg/kg MSDS
Use in pregnancy
Animal studies have determined that this drug causes fetal harm [FDA label].
Breastfeeding
In studies of rat models, this tizanidine was found excreted in the breastmilk with a milk-to-blood ratio of 1.8:1 [FDA label].
Always consult your doctor or midwife before taking any medicine during pregnancy or while breastfeeding. Source: DrugBank (CC BY-NC 4.0).
Official documents, adverse reaction reporting, and safety monitoring
Report a side effect
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Official medicine documents
Safety monitoring data
Yellow Card reports
The MHRA Yellow Card scheme collects reports of suspected side effects from healthcare professionals and patients. View the Drug Analysis Profile (iDAP) for real-world adverse reaction data.
View Drug Analysis Profile
Suspected adverse reactions reported for Tizanidine
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Interactive Drug Analysis Profiles for all medicines
Report a side effect
Submit a Yellow Card report to the MHRA
Data from the MHRA Yellow Card scheme. A reported reaction does not necessarily mean the medicine caused it. Contains public sector information licensed under the Open Government Licence v3.0.
EudraVigilance
The European Medicines Agency (EMA) collects suspected adverse reaction reports from across the EU/EEA through the EudraVigilance system. Search for safety data on this medicine.
View EudraVigilance report
Suspected adverse reactions reported for Tizanidine
About EudraVigilance
Learn about EU pharmacovigilance and safety monitoring
EudraVigilance data is published by the European Medicines Agency (EMA). A suspected adverse reaction is not necessarily caused by the medicine.
23 branded products available
MHRA licensed products
View all licensed products for Tizanidine on the MHRA register
Tizagelan 4mg tablets
Tizanidine 4mg tablets
Tizanidine 4mg tablets
Tizanidine 4mg tablets
Tizanidine 4mg tablets
Tizanidine 4mg tablets
Tizanidine 4mg tablets
Tizanidine 4mg tablets
Tizanidine 4mg tablets
This is the NHS Drug Tariff indicative price used for reimbursement purposes. It may not reflect the price paid by patients or pharmacies.
View full Drug TariffSource: NHS Drug Tariff via NHSBSA. Derived from dm+d VMPP (Virtual Medicinal Product Pack) pricing data. Contains public sector information licensed under the Open Government Licence v3.0.
WHO defined daily dose (DDD)
12 mg
Not a recommended dose. The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a statistical measure used for research and comparison purposes only.
Source: WHO Collaborating Centre for Drug Statistics Methodology, distributed via NHS dm+d BNF mapping files. Contains public sector information licensed under the Open Government Licence v3.0.
Therapeutically similar medicines
Similarity based on WHO Anatomical Therapeutic Chemical (ATC) classification and NHS BNF section grouping. Source data: NHS dm+d via TRUD (OGL v3.0), WHO ATC/DDD Index.
NHS prescribing volume and spending trends
Clinical guidelines and formulary information
British National Formulary
Tizanidine
Source: British National Formulary, NICE. Joint Formulary Committee. Contains public sector information licensed under the Open Government Licence v3.0.
NICE clinical guidance(2)
Motor neurone disease: assessment and management (NG42)
Stroke rehabilitation in adults (NG236)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
Pharmacy stock checkers
Search for this medicine at major UK pharmacy chains. These links open the retailer's own website — results depend on their current online catalogue.
Supply & product information
Official product databases and supply status monitoring
Pharmacy links redirect to the retailer's own search and do not represent real-time stock levels. emc (electronic medicines compendium) is operated by Datapharm Ltd. Shortage information sourced from NHS Specialist Pharmacy Service (SPS), sps.nhs.uk.
Codes for healthcare professionals and prescribing systems
These codes are used by healthcare IT systems and prescribers to identify this medicine.
NHS UK identifiers
Browse tools
SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0. BNF codes from NHS Business Services Authority (NHSBSA). ATC codes from the WHO Collaborating Centre for Drug Statistics Methodology (whocc.no).
Active and completed clinical studies from ClinicalTrials.gov
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
38 found
Half-life
2.5 hours
Mechanism
Tizanidine reduces spasticity by causing presynaptic inhibition of motor neurons…
Food interactions
2 warnings
Human targets
3 targets
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
40%
Half-life
2.5 hours
Protein binding
30%
Volume of distribution
2.4 L/kg
Metabolism
95%
Elimination
Clearance
50%
Tizanidine clearance is found to be decreased by more than 50% in elderly patients with renal insufficiency (creatinine…
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
Initially approved by the FDA in 1996, tizanidine is an Alpha-2 adrenergic receptor agonist reducing spasticity by the presynaptic inhibition of excitatory neurotransmitters that cause firing of neurons promoting muscle spasm [FDA label].
Known interactions with other medications. Always consult a healthcare professional.
Showing 50 of 1599 interactions
Oral LD50 (rat): 414 mg/kg; Subcutaneous LD50 (rat): 282 mg/kg; Oral LD50 (mouse): 235 mg/kg MSDS
Use in pregnancy
Animal studies have determined that this drug causes fetal harm [FDA label]. Studies have not been performed in humans, and it is advisable to ensure that tizanidine use in pregnant women should be reserved for cases in which possible benefit clearly outweighs the possible risk to mother and unborn child F4471.
Use in breastfeeding
In studies of rat models, this tizanidine was found excreted in the breastmilk with a milk-to-blood ratio of 1.8:1 [FDA label]. In young nursing rats, abnormal results were obtained in tests indicative of central nervous system function.
Various developmental changes that may have been attributable to the drug were observed. It is unknown whether tizanidine is excreted in human milk. It is a lipid-soluble drug, however, and likely to be excreted into breast milk F4471.
Carcinogenesis and mutagenesis
No signs of carcinogenicity were observed in two dietary studies performed in rodent models. Tizanidine was given to mice for 78 weeks at doses reaching a maximum 16 mg/kg (equivalent to twice the maximum recommended human dose).
In addition, the drug was given to rats for 104 weeks at doses reaching 9 mg/kg (equivalent to 2.5 times the maximum recommended human dose). There was a lack of a statistically significant increase in the occurrence of tumors in either study group F4471.
Tizanidine was not found to be mutagenic or clastogenic in several laboratory essays, including the bacterial Ames test, the mammalian gene mutation test, in addition to the chromosomal aberration test in Chinese hamster cells and several other assays F4471.
This drug is centrally acting and leads to a reduction in the release of excitatory amino acids like glutamate and aspartate, which cause neuronal firing that leads to muscle spasm. The above reduction and excitatory neurotransmitter release results in presynaptic inhibition of motor neurons. The strongest effect of tizanidine has been shown to occur on spinal polysynaptic pathways. The anti-nociceptive and anticonvulsant activities of tizanidine may also be attributed to agonist action on Alpha-2 receptors. Tizanidine also binds with weaker affinity to the Alpha-1 receptors, explaining its slight and temporary effect on the cardiovascular system T574.
Spasticity is an increase in muscle accompanied by uncontrolled, repetitive contractions of skeletal muscles which are involuntary.
The patient suffering from muscle spasticity may have reduced mobility and high levels of pain, contributing to poor quality of life and problems performing activities of personal hygiene and care [A177640].
General effects
Tizanidine is a rapidly acting drug used for the relief of muscle spasticity when it is required for performing specific activities. It acts as an agonist at Alpha-2 adrenergic receptor sites and relieves symptoms of muscle spasticity, allowing the continuation of normal daily activities. In animal models, tizanidine has not been shown to exert direct effects on skeletal muscle fibers or the neuromuscular junction, and has shown no significant effect on monosynaptic spinal reflexes (consisting of the communication between only 1 sensory neuron and 1 motor neuron) [L6064]. The frequency of muscle spasm and clonus are shown to be decreased by tizanidine T574. Tizanidine shows a stronger action on polysynaptic reflexes, which involve several interneurons (relay neurons) communicating with motor neurons stimulating muscle movement [L6064].
Effects on blood pressure and heart rate
This drug decreases heart rate and blood pressure in humans [A177559][A177589]. Despite this, rebound hypertension and tachycardia along with increased spasticity can occur when tizanidine is abruptly discontinued [A177643].
How the body processes this drug — absorption, distribution, metabolism, and elimination
Effect of food on absorption
Food has been shown to increase absorption for both the tablets and capsules.
The increase in absorption with the tablet (about 30%) was noticeably higher than the capsule (~10%). When the capsule and tablet were administered with food, the amount absorbed from the capsule was about 80% of the amount absorbed from the tablet [FDA label]. It is therefore advisable to take this drug with food for increased absorption, especially in tablet form.
Tizanidine clearance is found to be decreased by more than 50% in elderly patients with renal insufficiency (creatinine clearance < 25 mL/min)
compared to healthy elderly subjects; this would be expected to lead to a longer duration of clinical effect. This drug should be used with caution in patients with renal impairment [FDA label].
Proteins and enzymes this drug interacts with in the body
Blocking its activation with efaroxan abolished rilmenidine-induced mitogen-activated protein kinase phosphorylation in RVLM neurons (By similarity). Acts as a modulator of Rac-regulated signal transduction pathways (By similarity). Suppresses Rac1-stimulated cell migration by interacting with PAK1 and inhibiting its kinase activity (By similarity).
Also blocks Pak-independent Rac signaling by interacting with RAC1 and inhibiting Rac1-stimulated NF-kB response element and cyclin D1 promoter activation (By similarity). Also inhibits LIMK1 kinase activity by reducing LIMK1 'Tyr-508' phosphorylation (By similarity). Inhibits Rac-induced cell migration and invasion in breast and colon epithelial cells (By similarity).
Inhibits lamellipodia formation, when overexpressed (By similarity). Plays a role in protection against apoptosis. Involved in association with IRS4 in the enhancement of insulin activation of MAPK1 and MAPK3.
When overexpressed, induces a redistribution of cell surface ITGA5 integrin to intracellular endosomal structures
Enzymes involved in drug metabolism — important for understanding drug interactions
ATC M03BX02
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Show
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Tizanidine
Additional database identifiers
Drugs Product Database (DPD)
11821
ChemSpider
5287
BindingDB
50240671
ZINC
ZINC000019702309
HUGO Gene Nomenclature Committee (HGNC)
HGNC:277
GenAtlas
ADRA1A
GeneCards
ADRA1A
GenBank Gene Database
D25235
GenBank Protein Database
433201
Guide to Pharmacology
22
UniProt Accession
ADA1A_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:278
GenAtlas
ADRA1B
GeneCards
ADRA1B
GenBank Gene Database
M99589
Guide to Pharmacology
23
UniProt Accession
ADA1B_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:280
GenAtlas
ADRA1D
GeneCards
ADRA1D
GenBank Gene Database
M76446
GenBank Protein Database
177807
Guide to Pharmacology
24
UniProt Accession
ADA1D_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:281
GenAtlas
ADRA2A
GeneCards
ADRA2A
GenBank Gene Database
M23533
GenBank Protein Database
178196
Guide to Pharmacology
25
UniProt Accession
ADA2A_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:282
GenAtlas
ADRA2B
GeneCards
ADRA2B
GenBank Gene Database
M34041
GenBank Protein Database
178198
Guide to Pharmacology
26
UniProt Accession
ADA2B_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:283
GenAtlas
ADRA2C
GeneCards
ADRA2C
GenBank Gene Database
J03853
GenBank Protein Database
178194
Guide to Pharmacology
27
UniProt Accession
ADA2C_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:18006
GeneCards
NISCH
GenBank Gene Database
AF082516
GenBank Protein Database
3462807
UniProt Accession
NISCH_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:2596
GenAtlas
CYP1A2
GeneCards
CYP1A2
GenBank Gene Database
Z00036
Guide to Pharmacology
1319
UniProt Accession
CP1A2_HUMAN
International reference pricing
Reference pricing from DrugBank. Prices are indicative and may not reflect current UK costs.
Source: DrugBank. Used under CC BY-NC 4.0 academic licence for non-commercial purposes.
Patent information
2 active patents, 1 expired
Source: DrugBank · CC BY-NC 4.0. Patent data sourced from national patent offices. Expiry dates may not reflect extensions, regulatory exclusivity periods, or legal challenges.
DrugBank citations
If you use DrugBank data in your research, please cite the following publications: