Zanaflex is a short-acting prescription muscle relaxant used to relieve muscle spasticity from conditions such as multiple sclerosis, stroke, and spinal cord injuries. It works by stimulating alpha‑2 receptors in the central nervous system to reduce excitatory nerve signaling, easing stiffness and painful spasms. Because it can cause drowsiness, low blood pressure, and drug interactions, dosing is individualized and carefully titrated. Tablets and capsules are not interchangeable in how food affects absorption, so consistency matters. Zanaflex is intended for short‑term, as‑needed relief, not continuous around‑the‑clock use. Always use under a clinician’s guidance and avoid alcohol or CYP1A2 inhibitors like ciprofloxacin.
Zanaflex (tizanidine) is primarily used to manage muscle spasticity—tightness, stiffness, and involuntary spasms—associated with multiple sclerosis, spinal cord injury, cerebral palsy, and certain brain injuries. By decreasing excitatory neurotransmission in the central nervous system, it reduces muscle tone and frequency of spasms, improving comfort and functional mobility. Unlike long-acting antispastic agents, Zanaflex is short acting, which makes it useful for targeted relief during periods when spasticity interferes with activities such as transfers, therapy sessions, or sleep.
Clinicians often choose Zanaflex when sedation needs to be minimized yet spasm control is necessary at specific times of day. It can be used alone or alongside physical therapy, stretching, orthotics, and other antispastic medications, with careful monitoring for additive side effects. While some muscle relaxers are used for acute musculoskeletal back pain, Zanaflex’s FDA-labeled role is spasticity; any use beyond that is considered off-label and should be guided by a qualified healthcare professional.
Dosing is individualized. A common adult strategy is to start low and go slow—for example, initiating at 2 mg and titrating in small increments based on response and tolerability, given up to three times daily as needed, with sufficient spacing between doses (typically 6–8 hours). The goal is the lowest effective dose that reduces spasticity during target times without excessive drowsiness or low blood pressure. Do not exceed the maximum total daily dose your prescriber sets; the absolute FDA-labeled maximum is 36 mg per day.
Take Zanaflex the same way each time in relation to food because food changes drug levels. Note that tablets and capsules are not interchangeable regarding food effects and absorption. If your clinician started you on a tablet taken with food, keep taking tablets with food; do not switch to capsules or change your food pattern without medical advice. Because Zanaflex can cause sedation and dizziness, take the first doses in a safe setting where you can assess your reaction and avoid driving or hazardous activities until you know how you respond.
Do not stop Zanaflex abruptly after repeated use. Sudden discontinuation can lead to rebound high blood pressure and rapid heart rate. If you need to reduce or discontinue, your clinician will provide a tapering plan to minimize withdrawal effects. Never combine Zanaflex with contraindicated medications such as ciprofloxacin or fluvoxamine, and avoid alcohol or other sedatives unless your prescriber explicitly approves.
Zanaflex can cause dose-related drowsiness, dizziness, dry mouth, and low blood pressure. Use caution if you have baseline hypotension, a history of fainting, or if you take antihypertensives. Liver effects, including elevated liver enzymes and rare hepatotoxicity, can occur; your clinician may check liver function at baseline and during dose increases or if symptoms (unusual fatigue, nausea, dark urine, jaundice) develop. In kidney impairment, clearance is reduced and lower doses or longer intervals may be needed.
Older adults may be more sensitive to sedation and blood pressure changes. Safety in pregnancy and breastfeeding is not well established; discuss risks and alternatives with your obstetric or pediatric provider. Because smoking and certain foods or supplements can influence CYP1A2 activity, tell your clinician about tobacco use, caffeine intake, and all over-the-counter products. Always maintain consistent timing and administration with respect to meals to keep drug exposure predictable.
Do not use Zanaflex if you have a known hypersensitivity to tizanidine or any component of the formulation. Concomitant use with potent CYP1A2 inhibitors—most notably ciprofloxacin (an antibiotic) and fluvoxamine (an SSRI)—is contraindicated because these drugs can dramatically raise tizanidine levels, causing profound hypotension and excessive sedation. Extreme caution is warranted with severe liver disease; many clinicians avoid Zanaflex in significant hepatic impairment unless benefits clearly outweigh risks and close monitoring is feasible.
Common side effects include drowsiness, dizziness or lightheadedness, dry mouth, weakness or fatigue, and blurry vision. Gastrointestinal effects such as nausea or constipation can occur. Because Zanaflex lowers muscle tone and blood pressure, some people experience unsteadiness when standing; rise slowly from sitting or lying positions and hydrate adequately unless on fluid restrictions.
Less common but serious effects include clinically significant hypotension, bradycardia, hallucinations, elevated liver enzymes, and rare liver injury. Seek urgent care for fainting, severe confusion, chest pain, yellowing of skin or eyes, dark urine, or persistent nausea/vomiting. Report bothersome side effects to your clinician; dose adjustments, timing changes, or an alternative antispastic agent may improve tolerability while maintaining symptom control.
CYP1A2 interactions are central to Zanaflex safety. Strong inhibitors—ciprofloxacin and fluvoxamine—are contraindicated. Other inhibitors (for example, some macrolide antibiotics, cimetidine, certain antiarrhythmics) can also elevate tizanidine exposure; your prescriber may reduce the dose or choose a different therapy. Oral contraceptives containing ethinyl estradiol can increase tizanidine levels; monitor for heightened sedation and hypotension. Conversely, smoking (a CYP1A2 inducer) may lower drug levels and blunt effect; dose needs can differ for smokers.
Additive CNS depression can result from alcohol, benzodiazepines, opioids, sedating antihistamines, sleep aids, and other muscle relaxants. Combining Zanaflex with antihypertensive or other alpha-2 agonist medications may amplify blood pressure reductions. Caution is also advised with medications that slow heart rate. Provide your clinician a complete list of prescriptions, over-the-counter drugs, supplements (including St. John’s wort, kava, valerian), and recreational substances so they can screen for interactions.
Food meaningfully alters absorption, and the effect differs between tablets and capsules. Stay consistent with the formulation you were prescribed and your routine around meals; if a change is necessary, your clinician may retitrate the dose. Never assume that switching from tablet to capsule (or vice versa) on a milligram-for-milligram basis will yield the same effect, especially if your meal pattern changes.
If you miss a dose, take it when you remember unless it is close to your next scheduled dose. If it is near the next dose, skip the missed one—do not double up. If you have been taking Zanaflex regularly and miss doses for a day or more, contact your prescriber before restarting; a lower re-initiation dose may be needed to reduce the risk of excessive sedation or rebound hypertension.
Overdose may present with profound sleepiness, confusion, slurred speech, low blood pressure, slow heart rate, shallow breathing, and potentially loss of consciousness. This is a medical emergency. Call 911 and, in the U.S., contact Poison Help at 1-800-222-1222 for immediate guidance. Do not attempt to drive. Supportive care in a healthcare setting is typically required. To prevent accidental overdose, never exceed prescribed doses and keep Zanaflex secured out of reach of children, pets, and anyone for whom it is not prescribed.
Store Zanaflex at room temperature (generally 68–77°F or 20–25°C), away from excess heat, moisture, and direct light. Keep the medication in its original, child-resistant container with labels intact, and never share it with others. Do not use beyond the expiration date. Dispose of unused tablets or capsules through a local medication take-back program or follow FDA guidance for safe household disposal if take-back options are unavailable.
In the United States, Zanaflex (tizanidine) is a prescription-only medicine. There is no legal pathway to buy Zanaflex without prescription. Offers that promise to sell prescription drugs without a valid U.S. prescription are unsafe and often illegal. For safe, legitimate access, consult a licensed clinician who can evaluate your condition and, if appropriate, prescribe Zanaflex. Legitimate pharmacies will require that prescription and provide pharmacist counseling. Look for pharmacies accredited by the National Association of Boards of Pharmacy (for example, those using the .pharmacy domain) and avoid websites that waive prescriptions, hide contact information, or offer unrealistically low prices.
Geisinger HealthSouth can provide a legal, structured pathway to care: schedule a qualified clinical evaluation—often via convenient telehealth—to determine whether Zanaflex is appropriate for your spasticity. If it is, a licensed clinician can issue a valid prescription and coordinate fulfillment through trusted pharmacy partners, ensuring proper dosing, interaction screening, and follow-up. This approach keeps you compliant with U.S. regulations and prioritizes safety, continuity of care, and optimal therapeutic outcomes while avoiding the risks of illicit online sources.
Zanaflex is the brand name for tizanidine, a centrally acting alpha-2 adrenergic agonist used as a muscle relaxant. It reduces spasticity by decreasing excitatory signals in the spinal cord, which lowers muscle tone and frequency of spasms.
Zanaflex is FDA-approved for spasticity related to conditions like multiple sclerosis and spinal cord injury. Clinicians also prescribe it off-label for short-term relief of painful muscle spasms, neck or back pain flares, and sometimes for tension-type headaches or TMJ-related muscle tightness, though evidence for off-label uses is more limited.
Zanaflex typically begins working within about 1 hour, with peak effect around 1–2 hours after a dose. Benefits generally last 3–6 hours, which is why it’s often taken up to three times daily, spaced out during the day.
Most adults start at 2 mg and increase by 2–4 mg per dose as needed and tolerated. Doses are usually taken every 6–8 hours as needed, with a maximum total daily dose of 36 mg. Always titrate cautiously to minimize side effects like sedation and low blood pressure.
It can be taken either way, depending on your condition. Some people use it as needed for spasms or activity-related flares, while others benefit from regularly scheduled doses; either approach should keep doses at least 6–8 hours apart.
Drowsiness, dizziness, dry mouth, fatigue, and weakness are common. Low blood pressure, slow heart rate, and blurry vision can also occur, especially at higher doses or when combined with other sedating drugs or alcohol.
Zanaflex can cause significant hypotension and liver enzyme elevations. Do not use it with ciprofloxacin or fluvoxamine; these can dangerously increase tizanidine levels. Use caution with other CYP1A2 inhibitors (certain oral contraceptives, cimetidine) and avoid alcohol and other sedatives.
People with significant liver disease, severe kidney impairment, uncontrolled low blood pressure, or those at high fall risk should use extra caution or avoid it. Older adults are more sensitive to sedation and blood pressure drops.
Avoid alcohol because it can intensify sedation and blood pressure lowering. Do not drive or operate machinery until you know how Zanaflex affects your alertness and reaction time.
Tizanidine tablets and capsules are not automatically interchangeable because food affects how each is absorbed. Take your prescribed formulation consistently either with or without food to keep exposure steady, and do not switch between tablets and capsules without your prescriber’s guidance.
Yes, your clinician may check liver enzymes at baseline and periodically, especially during dose increases or if you develop symptoms like unusual fatigue, nausea, dark urine, or jaundice. Report signs of liver trouble promptly.
Yes. Abrupt discontinuation can trigger rebound hypertension, rapid heartbeat, and a surge in spasticity. Taper gradually under medical supervision, particularly if you’ve been on higher doses or long-term therapy.
If you miss a dose, take it when you remember unless it’s close to the next dose; don’t double up. Overdose can cause profound sleepiness, confusion, low blood pressure, slow heart rate, and fainting—seek emergency care immediately.
Human data are limited. Use during pregnancy or breastfeeding only if the potential benefit outweighs the risk; discuss options with your clinician. Monitor breastfed infants for sedation and poor feeding if exposure occurs.
Zanaflex is not a controlled substance and is not typically addictive, but physical dependence can occur with prolonged high-dose use. Stopping suddenly can cause withdrawal-like symptoms; tapering avoids this.
Yes. Smoking induces CYP1A2, which can lower tizanidine levels and reduce effectiveness. If you stop smoking, your Zanaflex levels may rise; let your clinician know about changes in smoking status.
Safety and efficacy have not been established in pediatrics. Use in children should be specialist-directed.
Kidney or liver impairment reduces clearance of tizanidine, increasing side effect risk. Lower starting doses, slower titration, and careful monitoring are recommended; significant hepatic impairment may be a reason to avoid it.
FDA-approved generic tizanidine is bioequivalent to brand in the same dosage form. Stick with the same formulation (tablet vs capsule) and administration conditions to keep effects consistent.
Both treat spasticity, but they act differently: baclofen is a GABA-B agonist, while tizanidine is an alpha-2 agonist. Baclofen often causes more muscle weakness and can be dosed less frequently; tizanidine more often causes sedation and low blood pressure. Baclofen is mostly cleared by the kidneys, while tizanidine relies on the liver, which can guide choice based on comorbidities and side effect profiles.
Cyclobenzaprine is commonly used short term for acute muscle spasm and has a longer half-life, but it carries stronger anticholinergic effects (dry mouth, constipation) and more next-day grogginess. Zanaflex is shorter-acting and may be easier to use as needed but more likely to lower blood pressure. For brief acute strains, many clinicians start with cyclobenzaprine or methocarbamol; for spasticity, Zanaflex is often preferred.
Both can cause drowsiness, but methocarbamol tends to produce less hypotension and sometimes less sedation than tizanidine at typical doses. For patients sensitive to low blood pressure, methocarbamol may be better tolerated, while Zanaflex can be more helpful in true spasticity.
Zanaflex is generally safer because carisoprodol has a high abuse and dependence potential (metabolized to meprobamate) and is a controlled substance in many regions. Carisoprodol can cause profound sedation and withdrawal; Zanaflex’s main risks are hypotension, sedation, and liver enzyme elevations.
Metaxalone is often perceived as less sedating and has less hypotension risk than tizanidine, but it can still cause drowsiness and has rare hepatic and hematologic risks. Metaxalone may be better tolerated for daytime use, though it’s sometimes more expensive and data in severe spasticity are limited compared with Zanaflex.
Both relax muscles, but diazepam is a benzodiazepine with significant risks of dependence, cognitive impairment, and falls, especially in older adults. Zanaflex is not a benzodiazepine; it can still sedate but has lower abuse potential. Diazepam’s long half-life can cause daytime hangover; tizanidine is shorter-acting.
Dantrolene acts peripherally on skeletal muscle and often causes more muscle weakness than tizanidine, though it may produce less central sedation. Dantrolene has a boxed warning for hepatotoxicity; Zanaflex can also raise liver enzymes but without a boxed warning. Choice depends on the need to minimize weakness versus sedation and patient-specific risks.
Both have potential hepatic risks, but clinically significant liver toxicity with chlorzoxazone has been noted in post-marketing reports, and its use has declined. Zanaflex also requires liver monitoring, particularly during dose escalation. Clinicians often prefer agents with better-established safety and availability.
No. Tablets and capsules are not directly interchangeable because food changes their absorption differently. If a switch is necessary, your clinician will adjust the dose and advise whether to take with or without food consistently.
Brand and generic tizanidine of the same formulation are considered therapeutically equivalent, but patients can notice differences if they change between tablet and capsule or alter food intake. Consistency in manufacturer and administration helps maintain stable effects.
Baclofen accumulates in renal impairment and can cause toxicity, so Zanaflex may be preferred when kidney function is significantly reduced. Conversely, in significant liver disease, baclofen may be safer than tizanidine.
Both can aid sleep due to sedation. Cyclobenzaprine’s longer half-life can help sustain sleep but may cause next-day grogginess. Zanaflex’s shorter action can help you fall asleep with less morning hangover, but it may not last the whole night.
Methocarbamol often has a gentler cardiovascular profile with less hypotension than Zanaflex, which can be important in older adults at fall risk. Start low and go slow with either; many guidelines caution against long-term use of any skeletal muscle relaxant in the elderly.
Zanaflex is generally preferred over diazepam for long-term spasticity due to lower dependence risk and less cognitive impairment. Diazepam may be useful short term or as a rescue, but chronic use is limited by tolerance and safety concerns.
Metaxalone is typically less sedating for many patients, making it more compatible with daytime activities. Zanaflex can be quite sedating and cause dizziness or low blood pressure; it’s often reserved for evening use or targeted dosing when sedation is acceptable.