Zanaflex (tizanidine) is a centrally acting, short-acting muscle relaxant prescribed to treat spasticity. Spasticity involves involuntary muscle stiffness and spasms that can limit mobility, interfere with sleep, and cause pain. It is commonly associated with neurological conditions such as multiple sclerosis (MS), spinal cord injury, traumatic brain injury, and certain neurodegenerative disorders. By reducing the heightened muscle tone that characterizes spasticity, Zanaflex can help improve movement and comfort in daily living.
Mechanistically, tizanidine is an alpha-2 adrenergic agonist. It works by decreasing excitatory signals in the central nervous system, dampening the excessive nerve activity that drives tight, rigid muscles. Unlike some longer-acting antispastic agents, Zanaflex’s effects peak relatively quickly and wear off within a few hours, making it useful for targeted symptom control (for example, around therapy sessions or during times when spasms are worst).
Patients and clinicians often use Zanaflex in a personalized manner—timed to activities, sleep, or rehabilitation goals—to maximize function while minimizing sedation. It can be used alone or alongside other modalities such as physical therapy, stretching, orthotics, and complementary antispastic medications when clinically appropriate.
It is important to distinguish spasticity from muscle spasms due to simple musculoskeletal strain. Zanaflex is not designed as a first-line treatment for routine back pain or acute muscle injuries. Its role is primarily in neurologically driven spasticity, where careful dosing and monitoring ensure effective, safe relief.
Brand-name Zanaflex and generic tizanidine are both available in the United States in tablets and capsules. Because food and formulation can change how much medication gets into your system, consistency in how you take it and avoiding formulation switches without guidance are key to stable symptom control.
Always use Zanaflex exactly as prescribed by your healthcare professional. Because response and tolerability vary widely, clinicians typically start with a low dose and adjust gradually based on symptom relief, daytime functioning, and side effects such as drowsiness or low blood pressure.
If you feel the current regimen is not adequately controlling spasticity—or if you are too sedated or dizzy—contact your healthcare provider. Never increase the dose or frequency on your own. Optimal dosing aims for the lowest effective amount at the right times of day to target symptoms while preserving alertness and safety.
Zanaflex can cause sedation and drops in blood pressure, especially during dose initiation and upward titration. Plan dosing to minimize risks such as falls or impaired performance at work, school, or while driving.
Your prescriber will review your full medication list to ensure there are no dangerous combinations. Inform your healthcare provider about any liver disease, severe kidney impairment, or a history of fainting or low blood pressure, as these conditions may affect suitability or dosing.
Most side effects are dose-related and may lessen as your body adjusts or if the dose is reduced. Common effects include:
Less common but more significant reactions can include:
Seek immediate medical attention if you experience signs of a severe allergic reaction, serious dizziness or fainting, severe abdominal pain, persistent nausea or vomiting, dark urine, yellowing of the skin or eyes, or new or worsening mental status changes. Report troublesome dry mouth, constipation, or excessive sleepiness; simple strategies or dose adjustments may help.
Tizanidine is metabolized primarily by the liver enzyme CYP1A2, so drugs that strongly affect this pathway can significantly raise or lower Zanaflex levels. To reduce risk, provide your clinician with a complete list of prescription drugs, over-the-counter medicines, vitamins, and herbal supplements.
Because interactions can be clinically significant, never start or stop a medication while taking Zanaflex without first consulting your healthcare provider. If you smoke, tell your clinician; a change in smoking status can alter tizanidine response.
If you miss multiple doses and are on a higher regimen, contact your prescriber before resuming to avoid abrupt changes in blood pressure or oversedation.
Symptoms of overdose can include extreme drowsiness, confusion, slurred speech, slow heartbeat, low blood pressure, fainting, shallow or slowed breathing, and coma in severe cases. If an overdose is suspected:
Medical teams provide supportive care; there is no specific antidote. Hospital monitoring may be required until vital signs stabilize.
This material is for educational purposes only and is not a substitute for individualized medical advice, diagnosis, or treatment. Always consult a licensed healthcare professional regarding your specific health situation and before starting, changing, or stopping any medication. While efforts have been made to ensure accuracy, no guarantee is provided, and we assume no responsibility for how this information is used.
In the United States, Zanaflex (tizanidine) is an FDA-approved, prescription-only medication. By law, pharmacies must dispense it only pursuant to a valid prescription from a licensed prescriber following an appropriate clinical evaluation. This applies equally to in-person and online pharmacies.
If you are considering purchasing Zanaflex online, prioritize your safety: confirm that the service requires a valid prescription, verify licensure and accreditation, and consult your healthcare provider about the appropriateness of tizanidine for your condition and potential interactions with your current medications.
Zanaflex is the brand name for tizanidine, a short-acting central alpha-2 adrenergic agonist muscle relaxant. It reduces spasticity by decreasing excitatory signals to motor neurons in the spinal cord, which helps relax tight muscles.
Zanaflex is used to manage muscle spasticity due to conditions like multiple sclerosis, spinal cord injury, and certain neurological disorders. It is sometimes used off-label for painful acute muscle spasms when other options are not suitable.
Effects typically begin within 1 to 2 hours of a dose, peak around 2 to 3 hours, and wear off by about 6 to 8 hours. Its short duration makes it useful for targeted times of day when spasticity is worst.
Take it exactly as prescribed, usually up to three times daily with 6–8 hours between doses. Be consistent with food—take it the same way each time (always with food or always without) because food changes absorption. Do not switch between capsules and tablets or different brands without medical guidance.
Dosing is individualized. Many adults start at 2 mg and increase in small steps as needed and tolerated. The maximum total is 36 mg per day, with no more than three doses in 24 hours.
Drowsiness, dizziness, dry mouth, fatigue, and weakness are common. Low blood pressure, especially on standing, can occur and may cause lightheadedness or fainting.
Call your clinician if you notice yellowing of skin or eyes, dark urine, severe fatigue, unexplained nausea or abdominal pain (possible liver injury), very slow heartbeat, severe low blood pressure, hallucinations, or allergic reactions like swelling or rash.
Yes. Tizanidine can elevate liver enzymes and rarely cause serious liver injury. Your clinician may check liver function at baseline and after dose increases or if symptoms suggest liver problems.
Avoid fluvoxamine and ciprofloxacin; they can dangerously raise tizanidine levels and blood pressure-lowering effects. Use caution with other CYP1A2 inhibitors (e.g., certain oral contraceptives, cimetidine, zileuton), other blood pressure medicines, and sedatives like benzodiazepines, opioids, or alcohol.
Use caution. Zanaflex can cause sedation, dizziness, and slowed reaction times. Avoid driving or hazardous tasks until you know how it affects you.
If you take it regularly and miss a dose, take it when you remember unless it is close to your next dose. Do not double up. If you use it as needed, take it when symptoms occur, respecting the minimum 6–8 hour spacing.
If you use higher or frequent doses, do not stop abruptly. Sudden discontinuation can cause rebound high blood pressure, fast heart rate, and increased spasticity. Taper with your clinician’s guidance.
Zanaflex is not a controlled substance and is not considered addictive. However, dependence-like withdrawal symptoms can occur after high-dose or long-term use, so tapering is recommended.
No. Tablets and capsules have different absorption characteristics, especially with food. Stay on the same formulation and take it consistently with regard to meals unless your prescriber directs a switch.
Avoid if you are taking fluvoxamine or ciprofloxacin, or if you have known hypersensitivity to tizanidine. Use extreme caution or avoid in significant liver disease. People with severe kidney impairment need careful dose adjustments and monitoring.
Avoid combining Zanaflex with alcohol. Alcohol increases sedation, impairs coordination, and can worsen low blood pressure. If you have consumed alcohol, skip the tizanidine dose and speak to your clinician about safe timing.
Human data are limited. Zanaflex should be used in pregnancy only if the potential benefits outweigh potential risks. Discuss alternatives and timing with your obstetric provider.
It is unknown if tizanidine passes into human breast milk. Because of possible sedation or feeding issues in the infant, use caution and consult your pediatrician and prescriber about risks and monitoring.
Tell your surgical and anesthesia teams you take tizanidine. Because it can cause sedation and low blood pressure, your team may advise holding or adjusting the dose before surgery while avoiding abrupt withdrawal if you use higher or frequent doses.
Older adults may be more sensitive to drowsiness and low blood pressure. Lower starting doses, slower titration, fall-risk precautions, and blood pressure monitoring are recommended.
Tizanidine clearance is reduced in significant kidney impairment, increasing side effects. Lower doses and careful monitoring are needed; discuss with your nephrologist or prescriber.
Caution is essential. Combining tizanidine with other sedatives increases risk of dangerous drowsiness, slowed breathing, confusion, and falls. If co-use is necessary, use the lowest effective doses with close monitoring.
Some combined oral contraceptives can moderately inhibit CYP1A2 and raise tizanidine levels. This may increase sedation and low blood pressure risk. Your clinician may adjust your Zanaflex dose and monitor for side effects.
Both help spasticity. Zanaflex tends to be more sedating and shorter-acting, making it useful for targeted times (e.g., at night). Baclofen may cause more muscle weakness and is renally cleared, which matters in kidney disease. Choice depends on side effects, comorbidities, and treatment goals.
Cyclobenzaprine is for short-term acute musculoskeletal spasm and is more anticholinergic (dry mouth, constipation) with a long half-life causing next-day grogginess. Zanaflex targets spasticity and has a shorter duration but more blood pressure lowering. Choose based on condition (spasticity vs acute spasm) and side-effect profile.
Methocarbamol is often used for acute back/neck strain and may cause less hypotension but can still sedate. Zanaflex is more established for neurologic spasticity. Methocarbamol is usually dosed multiple times daily; Zanaflex is titrated to effect with careful spacing.
Metaxalone can be less sedating for some, but it also carries liver warnings and can be costly. Zanaflex offers targeted spasticity relief but more frequent dizziness/low blood pressure. Liver monitoring and individual response guide choice.
Dantrolene acts peripherally on muscle and is effective for severe spasticity but carries a higher risk of serious liver toxicity and is often reserved for refractory cases. Zanaflex acts centrally with a shorter duration and is commonly tried first. Liver function monitoring is important for both.
Diazepam can reduce spasticity but has significant risks of dependence, cognitive impairment, and falls, especially in older adults. Zanaflex lacks benzodiazepine dependence risk but still sedates and lowers blood pressure. Many guidelines prefer tizanidine or baclofen over long-term diazepam.
Carisoprodol has high abuse and dependence potential and is generally discouraged. Zanaflex is typically preferred for spasticity due to a safer long-term profile when monitored appropriately.
Zanaflex’s short onset and duration can be helpful for nighttime spasms or activities that provoke spasticity. Baclofen may provide steadier baseline control but can cause daytime weakness. Some patients use low-dose Zanaflex at night alongside daytime baclofen under supervision.
Orphenadrine is an anticholinergic muscle relaxant for acute musculoskeletal pain, with side effects like dry mouth, blurry vision, and confusion in older adults. Zanaflex is not anticholinergic but can lower blood pressure and sedate; it is favored for neurologic spasticity.
Chlorzoxazone is used for acute muscle spasm and can rarely cause liver toxicity and discoloration of urine. Zanaflex also affects the liver but is better studied for spasticity. Monitoring and patient-specific risks drive the choice.
Metaxalone is often perceived as less sedating in some patients, making it a consideration for daytime use in acute spasm. Zanaflex commonly causes drowsiness and low blood pressure; if daytime function is critical, metaxalone may be preferred for acute issues, while Zanaflex is targeted for spasticity.
The active ingredient is the same, but excipients and the impact of food on absorption can vary by product and by tablet vs capsule. Stay consistent with the same formulation and discuss any switches with your prescriber if you notice changes in effect.
Cyclobenzaprine is commonly used short-term for jaw muscle spasm due to its TCA-like profile, but next-day sedation can be problematic. Zanaflex may help targeted episodes with a shorter window of effect. The choice depends on timing needs and tolerability, guided by a dentist or clinician experienced in TMJ care.
