Tizanidine
Pronunciation: (zan-uh-flex) (tye-ZAN-i-deen).
- Generic name
- Tizanidine
- Brand names
- Tizalud, Zanaflex, Sirdalud, Tizan
- Drug class
- Musculoskeletal & Connective Tissue
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What Tizanidine is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Tizanidine works
Tizanidine is a centrally acting alpha-2 adrenergic agonist. It works by inhibiting presynaptic motor neurons in the spinal cord, reducing the release of excitatory amino acids and thus decreasing spasticity and muscle tone. This action results in reduced muscle spasms and improved mobility in patients with spasticity. (1)
What Tizanidine is used for
Muscle spasticity
Muscle spasticity (1)
Multiple sclerosis-related spasticity
Multiple sclerosis-related spasticity (1)
Spinal cord injury-related spasticity
Spinal cord injury-related spasticity (1)
Stroke-related spasticity
Stroke-related spasticity (1)
Before taking Tizanidine
Do not take / not appropriate for
- Contraindicated in patients with hypersensitivity to tizanidine, and those taking potent CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin) due to risk of severe hypotension and increased adverse effects. (Contraindication) (1)
Tell your clinician about
(1)How to take Tizanidine
- General Instructions: Take Zanaflex exactly as prescribed by your healthcare provider. Do not take more than the recommended dose or use it more frequently than directed.. Adult Dosing: Initial dose: 2 mg orally up to three times daily as needed. Dose may be increased by 2-4 mg per dose at intervals of 1-4 days, up to a maximum of 36 mg per day, divided into three or four doses.. Pediatric Dosing: Safety and efficacy in children under 18 years have not been established. Use in pediatric patients is not routinely recommended.. Administration: Take with or without food, but be consistent in how you take it (with food or always without food). Swallow tablets or capsules whole with water.. When To Seek Review: Do not stop taking Zanaflex suddenly. If discontinuation is needed, your doctor will gradually reduce your dose to prevent withdrawal symptoms such as high blood pressure or rapid heart rate.. Storage: Store at room temperature (20°C to 25°C/68°F to 77°F), away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and resume your regular schedule. Do not take an extra dose to catch up.
Overdose
Symptoms of overdose may include severe drowsiness, confusion, slow or irregular heartbeat, difficulty breathing, or loss of consciousness. Seek emergency medical attention or call your local poison control center immediately. (1)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Drowsiness
Incidence: Reported in the clinician-authored database; frequency not established
Dry mouth
Incidence: Reported in the clinician-authored database; frequency not established
Dizziness
Incidence: Reported in the clinician-authored database; frequency not established
Weakness
Incidence: Reported in the clinician-authored database; frequency not established
Low blood pressure
Incidence: Reported in the clinician-authored database; frequency not established
Liver damage
Incidence: Reported in the clinician-authored database; frequency not established
Hallucinations
Incidence: Reported in the clinician-authored database; frequency not established
Bradycardia
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
May cause drowsiness and dizziness — serious
Symptoms: May cause drowsiness and dizziness; use caution with activities requiring alertness. Risk of severe hypotension, especially when combined with certain medications. Liver injury has been reported; monitor liver function during therapy. Abrupt discontinuation can cause withdrawal symptoms (hypertension, tachycardia). Significant drug interactions with CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin).
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindicated in patients with hypersensitivity to tizanidine, and those taking potent CYP1A2 inhibitors (e.g., fluvoxamine, ciprofloxacin) due to risk of severe hypotension and increased adverse effects. CORRECTED (FDA label): hepatic impairment is not merely a caution — Zanaflex is NOT RECOMMENDED in patients with hepatic impairment, since it is extensively metabolized by the liver. Use with caution and reduced doses in renal impairment (creatinine clearance under 25 mL/min, where clearance falls by more than half), in hypotension, or with a history of heart disease. Monitor for signs of liver dysfunction and CNS depression.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Zanaflex interacts with several medications, especially CYP1A2 inhibitors such as fluvoxamine and ciprofloxacin, which can significantly increase tizanidine levels and risk of side effects. Use caution with antihypertensives, other CNS depressants, and oral contraceptives. Always inform your healthcare provider about all medications and supplements you are taking. | (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
There are no adequate data on developmental risk from Zanaflex use in pregnant women. In animal studies, tizanidine given during pregnancy caused developmental toxicity (embryo-fetal and postnatal offspring death and growth deficits) at doses lower than those used clinically in humans. Discuss use during pregnancy with the clinician managing your care, weighing the benefit of spasticity control against this animal-data signal. (1)
Breastfeeding
There are no data on whether tizanidine passes into human breast milk or its effects on a breastfed infant or on milk production, though animal studies found tizanidine present in the milk of lactating animals. Your healthcare provider will weigh the benefits of breastfeeding against the potential risks from maternal Zanaflex use — discuss your individual situation with them. (1)
Children
Frequency: Not applicable.. Weight Based: Not recommended for pediatric use.. Max Daily Dose: Not applicable.. Max Single Dose: Not applicable.. Age Restrictions: Safety not established in children. (1)
Renal_impairment
The FDA label advises caution and reduced individual doses in people with significant kidney impairment (creatinine clearance under 25 mL/min), because clearance of the medicine falls by more than half — if a higher dose is needed, the individual dose is increased rather than how often it's taken. Liver impairment is treated more strictly: because tizanidine is broken down mainly by the liver, and the effect of liver impairment on the drug has not been formally studied, Zanaflex is not recommended at all in people with liver impairment. Tell the prescribing clinician about any kidney or liver disease before starting. (1)
Hepatic_impairment
The FDA label advises caution and reduced individual doses in people with significant kidney impairment (creatinine clearance under 25 mL/min), because clearance of the medicine falls by more than half — if a higher dose is needed, the individual dose is increased rather than how often it's taken. Liver impairment is treated more strictly: because tizanidine is broken down mainly by the liver, and the effect of liver impairment on the drug has not been formally studied, Zanaflex is not recommended at all in people with liver impairment. Tell the prescribing clinician about any kidney or liver disease before starting. (1)
Monitoring
(1)Storage
Store at 25°C (77°F); excursions permitted between 15°C and 30°C (59-86°F). Dispense in a container with a child-resistant closure. This applies to both the tablet and capsule forms of Zanaflex.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Muscle spasticity
Dose summary: Initial dose of 2 mg taken orally, with titration based on response and tolerability.
Renal context: The FDA label advises caution in patients with renal insufficiency (creatinine clearance under 25 mL/min), where clearance is reduced by more than 50%; during titration, individual doses should be reduced, and if higher doses are needed, the individual dose should be increased rather than the dosing frequency. Hepatic impairment is treated more strictly: the effect of hepatic impairment on tizanidine's pharmacokinetics has not been formally evaluated, but because tizanidine is extensively metabolized in the liver, hepatic impairment would be expected to have significant effects, and the label states Zanaflex is NOT recommended in patients with hepatic impairment. (1)
Frequently asked questions
What is Zanaflex (Tizanidine) used for?
Zanaflex is used to treat muscle spasticity associated with conditions like multiple sclerosis, spinal cord injury, or certain neurological disorders. It helps reduce muscle stiffness and spasms.
How quickly does Zanaflex start working?
Zanaflex usually begins to work within 1 to 2 hours after taking a dose, with peak effects seen around 2 to 3 hours.
Can I take Zanaflex with food?
Yes, but you should take it consistently either always with food or always without food, as food can affect how much medicine is absorbed.
Is Zanaflex habit-forming?
Zanaflex is not considered habit-forming, but stopping it suddenly can cause withdrawal symptoms. Always follow your doctor's instructions for discontinuation.
What should I do if I experience severe side effects?
Seek immediate medical attention if you experience symptoms like severe drowsiness, confusion, irregular heartbeat, difficulty breathing, or signs of liver problems.
Can I drink alcohol while taking Zanaflex?
No, you should avoid alcohol as it can increase the risk of drowsiness, dizziness, and other side effects.
Are there any medications I should avoid while taking Zanaflex?
Yes, avoid taking Zanaflex with strong CYP1A2 inhibitors (such as fluvoxamine or ciprofloxacin) and inform your doctor about all other medications you are taking.
What happens if I take too much Zanaflex (Tizanidine)?
Taking too much Zanaflex can lead to severe drowsiness, dizziness, blurred vision, low blood pressure, and a slow heart rate. In extreme cases, it may cause respiratory depression or coma. If you suspect an overdose, seek immediate emergency medical attention or call poison control. Do not attempt to self-treat the overdose.
Can I drink alcohol while taking Zanaflex (Tizanidine)?
It is strongly advised to avoid alcohol consumption while taking Zanaflex. Both Zanaflex and alcohol are central nervous system depressants. Combining them can significantly increase side effects such as drowsiness, dizziness, impaired coordination, and sedation, potentially leading to dangerous situations like falls or accidents. This interaction can also exacerbate the hypotensive effects of Zanaflex.
Is Zanaflex (Tizanidine) safe during pregnancy?
Zanaflex is generally not recommended during pregnancy, and its pregnancy category is not definitively established for human risk. Animal studies have shown adverse effects on the fetus. Therefore, it is crucial to consult your healthcare provider if you are pregnant, planning to become pregnant, or breastfeeding. They can assess the potential risks and benefits and recommend the safest course of action for your specific situation.
What is the mechanism of action of Tizanidine?
Tizanidine is a centrally acting alpha-2 adrenergic agonist. It works by inhibiting presynaptic motor neurons in the spinal cord, reducing the release of excitatory amino acids and thus decreasing spasticity and muscle tone. This action results in reduced muscle spasms and improved mobility in patients with spasticity. (1)
What is the generic name of Tizanidine?
The generic name is Tizanidine. It is sold under brand names including Tizalud, Zanaflex, Sirdalud, Tizan.
What class of drug is Tizanidine?
Tizanidine is classed as: Musculoskeletal & Connective Tissue.
References
- Zanaflex — Prescribing InformationDailyMed (U.S. National Library of Medicine) · United States · accessed 2026-08-07 · source 1
- TIZANIDINE TABLET [APHENA PHARMA SOLUTIONS - TENNESSEE, LLC ] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 2
- tizanidine — FDA approval record (Drugs@FDA ANDA076533)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 3
- Tizanidine — RxNorm normalized drug concept (RXCUI 236460)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 4
Brand names by country
Single-ingredient Tizanidine names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Tizanidne hydrochloride4 mg, 6 mg, 2 mg · bryant ranch prepack
- Zanaflex6 mg, 4 mg, 2 mg, 8 mg · legacy pharma usa, inc.
- Ontralfy2 mg/5mL · rosemont pharmaceuticals, llc
- TIZANDINE2 mg · direct_rx
Canada
- PAL-TIZANIDINE