TIZANIDINE HYDROCHLORIDE 4 mg Tablet, 20-count
🆔 Identity & classification
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🏷️ RxNorm drug class
This medicine belongs to the Central alpha-2 Adrenergic Agonist class.
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🏭 Manufacturer & labeler
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🩺 Clinical
Tizanidine is used to relieve muscle spasms, cramping, and tightness caused by certain conditions including multiple sclerosis (MS, a disease in which the nerves do not function properly and patients may experience weakness, numbness, loss of muscle coordination and problems with vision, speech, and bladder control) and spinal injury. Tizanidine is in a class of medications called skeletal muscle relaxants. It works by slowing action in the brain and nervous system to allow the muscles to relax.
Read the full MedlinePlus article ↗- Tizanidine is a muscle relaxant prescribed to manage spasticity — that's the uncomfortable muscle stiffness, tightness, or spasms that can come with conditions like multiple sclero...
- Yes, it actually matters a lot — and it's different depending on whether you're taking a tablet or a capsule. Food increases how much drug your body absorbs from the tablet, but it...
- Does it matter if I take tizanidine with food or without?
- Very likely, yes — drowsiness is one of the most common side effects and can be significant, especially when you first start or when the dose is being adjusted. It can interfere wi...
Patient education
Supplement & herbal interactions
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💊 What it looks like
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🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
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UNII 3SY5LH9PMK
Anhydrous lactose is a milk sugar with no water content. It acts as a filler and binder in tablets and capsules, adding bulk and helping ingredients stick together.
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UNII OP1R32D61U
Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
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Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
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UNII 4ELV7Z65AP
Stearic acid is a fatty acid derived from plant or animal sources. It acts as a binder and lubricant in tablets and capsules, helping them hold together and flow smoothly during manufacturing.
4 inactive ingredients listed in the exact product block matched to this NDC.
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ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
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💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per each | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $0.1130 | $2.26 / 20 tablets |
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🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| tizanidine 4 mg 00904-6418-61 | Major | 100 tablets | $0.032 | AB | Availability likely | — |
| Tizanidine 4 mg 16714-0172-01 | NorthStar | 150 tablets | $0.032 | AB | Availability likely | — |
| Tizanidine 4 mg 29300-0169-03 | Unichem | 300 tablets | $0.032 | AB | Availability likely | — |
| Tizanidine 4 mg 50268-0760-15 | AvPAK | 50 tablets | $0.032 | AB | Availability likely | — |
| Tizanidine 4 mg 57664-0503-18 | Sun | 1000 tablets | $0.032 | AB | Availability likely | — |
| Tizanidine 4 mg 68084-0645-01 | American | 100 tablets | $0.032 | AB | Availability likely | — |
| tizanidine 4 mg 00615-8469-39 | NCS | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 43063-0455-15 | PD-Rx | 15 tablets | — | AB | FDA listed | — |
| Tizanidine Hydrochloride 4 mg 49999-0347-01 | Quality | 120 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 50090-0840-00 | A-S | 120 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 50090-5767-00 | A-S | 120 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 50090-6756-00 | A-S | 120 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 50090-6757-00 | A-S | 90 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 50090-7889-00 | A-S | 90 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 51655-0603-20 | Northwind | 20 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 51655-0740-26 | Northwind | 90 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 55111-0180-03 | Dr. | 300 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 55154-7287-00 | Cardinal | 10 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 60505-0252-01 | Apotex | 100 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 60760-0505-04 | St. | 4 tablets | — | AB | FDA listed | — |
| Tizanidine Hydrochloride 4 mgthis 61919-0196-20 | TIZANIDINE | 20 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 63187-0009-30 | Proficient | 30 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 63187-0145-30 | Proficient | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 63187-0493-15 | Proficient | 15 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 63187-0673-14 | Proficient | 14 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 63629-1673-00 | Bryant | 112 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 63629-2371-01 | Bryant | 1000 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 64980-0659-03 | Rising | 30 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 67046-1444-03 | Coupler | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 67296-2263-02 | Redpharm | 15 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 67877-0614-05 | Ascend | 500 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 68071-3719-03 | NuCare | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 68071-4463-03 | NuCare | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 68071-5268-03 | NuCare | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 68788-7781-01 | Preferred | 100 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 68788-8741-01 | Preferred | 100 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 68788-8802-01 | Preferred | 100 tablets | — | AB | FDA listed | — |
| Zanaflex 4 mg 70515-0594-15 | Covis | 150 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 70518-0133-00 | REMEDYREPACK | 60 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 70518-1598-01 | REMEDYREPACK | 60 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 70518-3658-00 | REMEDYREPACK | 30 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 70518-4181-00 | REMEDYREPACK | 90 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 70771-1336-00 | Zydus | 1000 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 71335-0914-00 | Bryant | 112 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 71335-1016-00 | Bryant | 112 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 71335-2325-00 | Bryant | 112 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 71335-3016-01 | Bryant | 90 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 71610-0228-30 | Aphena | 30 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 71610-0776-16 | Aphena | 6000 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 71610-0864-16 | Aphena | 6000 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 72162-1642-00 | Bryant | 1000 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 72189-0602-30 | Direct_rx | 30 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 72578-0097-06 | Viona | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 72789-0325-30 | PD-Rx | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 72789-0327-20 | PD-Rx | 20 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 76420-0229-30 | Asclemed | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 76420-0339-00 | Asclemed | 1000 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 76420-0866-00 | Asclemed | 1000 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 76420-0886-00 | Asclemed | 1000 tablets | — | AB | FDA listed | — |
| Tizanidine HCL 4 mg 80425-0022-01 | Advanced | 60 tablets | — | AB | FDA listed | — |
| Tizanidine HCl 4 mg 80425-0023-01 | Advanced | 60 tablets | — | AB | FDA listed | — |
| Tizanidine HCL 4 mg 80425-0024-01 | Advanced | 60 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 80425-0453-01 | Advanced | 30 tablets | — | AB | FDA listed | — |
| tizanidine 4 mg 80425-0454-01 | Advanced | 30 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 82461-0721-60 | Medcore | 60 tablets | — | AB | FDA listed | — |
| Zanaflex 4 mg 83107-0004-15 | Legacy | 150 tablets | — | AB | FDA listed | — |
| Tizanidine 4 mg 85509-1180-01 | PHOENIX | 120 tablets | — | AB | FDA listed | — |
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⏳ Availability & generic status
This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
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🔬 Reported adverse events (FAERS)
Top reported reactions
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📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 61919-0196-30 | 30 TABLET in 1 BOTTLE (61919-196-30) | 2015-01-01 | Active |
| 61919-0196-40 | 40 TABLET in 1 BOTTLE (61919-196-40) | 2014-01-01 | Active |
| 61919-0196-60 | 60 TABLET in 1 BOTTLE (61919-196-60) | 2015-01-01 | Active |
| 61919-0196-72 | 72 TABLET in 1 BOTTLE (61919-196-72) | 2015-01-01 | Active |
| 61919-0196-90 | 90 TABLET in 1 BOTTLE (61919-196-90) | 2015-01-01 | Active |
| 61919-0196-20 You're viewing this | 20 TABLET in 1 BOTTLE (61919-196-20) | 2014-01-01 | Active |
You're viewing the smallest of 6 pack sizes for this product.
Pack size FAQ
What quantity is in NDC 61919-0196-20?
What is the difference between NDC 61919-0196-20 and NDC 61919-0196-30?
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🧭 About this NDC listing & data coverage
What data is (and isn’t) available for this NDC — tap to expand
| NDC identity (package / product / labeler codes) | ✓ Available |
| Labeler | ✓ Available |
| Product & package description | ✓ Available |
| Marketing category & status | ✓ Available |
| Active ingredient / dosage form / route | ✓ Available |
| FDA label (SPL via DailyMed) | ✓ Available |
| Package photos | ✓ Available |
| Inactive ingredients (structured) | ✓ Available |
| NADAC pharmacy acquisition price (CMS) | — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey. |
| Orange Book / therapeutic-equivalence data | ✓ Available |
| HCPCS J-code billing crosswalk | — Not published for this NDC Most self-administered / retail products have no J-code — that is normal. |
| Medicaid utilization (CMS SDUD) | — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold. |
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📄 Full prescribing information FDA SPL
🎯 Indications and Usage ▾
INDICATIONS & USAGE SECTION Tizanidine tablet is a short-acting drug for the management of spasticity. Because of the short duration of effect, treatment with tizanidine should be reserved for those daily activities and times when relief of spasticity is most important (see DOSAGE AND ADMINISTRATION).
⏱️ Dosage and Administration ▾
DOSAGE & ADMINISTRATION SECTION A single dose of 8 mg of tizanidine reduces muscle tone in patients with spasticity for a period of several hours. The effect peaks at approximately 1 to 2 hours and dissipates between 3 to 6 hours. Effects are dose-related.
Although single doses of less than 8 mg have not been demonstrated to be effective in controlled clinical studies, the dose-related nature of tizanidine's common adverse events make it prudent to begin treatment with single oral doses of 4 mg. Increase the dose gradually (2 to 4 mg steps) to optimum effect (satisfactory reduction of muscle tone at a tolerated dose). The dose can be repeated at 6 to 8 hour intervals, as needed, to a maximum of three doses in 24 hours.
The total daily dose should not exceed 36 mg. Experience with single doses exceeding 8 mg and daily doses exceeding 24 mg is limited. There is essentially no experience with repeated, single, daytime doses greater than 12 mg or total daily doses greater than 36 mg (see WARNINGS).
Food has complex effects on tizanidine pharmacokinetics, which differ with the different formulations. These pharmacokinetic differences may result in clinically significant differences when [1] switching administration of the tablet between the fed or fasted state, [2] switching administration of the capsule between the fed or fasted state, [3] switching between the tablet and capsule in the fed state, or [4] switching between the intact capsule and sprinkling the contents of the capsule on applesauce. These changes may result in increased adverse events or delayed/more rapid onset of activity, depending upon the nature of the switch.
For this reason, the prescriber should be thoroughly familiar with the changes in kinetics associated with these different conditions (see CLINICAL PHARMACOLOGY: Pharmacokinetics).
⛔ Contraindications ▾
CONTRAINDICATIONS SECTION Concomitant use of tizanidine with fluvoxamine or with ciprofloxacin, potent inhibitors of CYP1A2, is contraindicated. Significant alterations of pharmacokinetic parameters of tizanidine including increased AUC, t1/2, Cmax, increased oral bioavailability and decreased plasma clearance have been observed with concomitant administration of either fluvoxamine or ciprofloxacin. This pharmacokinetic interaction can result in potentially serious adverse events (See WARNINGS and CLINICAL PHARMACOLOGY: Drug Interactions).
Tizanidine tablets is contraindicated in patients with known hypersensitivity to Tizanidine tablets or its ingredients.
⚠️ Warnings ▾
WARNINGS SECTION LIMITED DATA BASE FOR CHRONIC USE OF SINGLE DOSES ABOVE 8 MG AND MULTIPLE DOSES ABOVE 24 MG PER DAY Clinical experience with long-term use of tizanidine at doses of 8 to 16 mg single doses or total daily doses of 24 to 36 mg (see Dosage and Administration) is limited. In safety studies, approximately 75 patients have been exposed to individual doses of 12 mg or more for at least one year or more and approximately 80 patients have been exposed to total daily doses of 30 to 36 mg/day for at least one year or more.
There is essentially no long-term experience with single, daytime doses of 16 mg. Because long-term clinical study experience at high doses is limited, only those adverse events with a relatively high incidence are likely to have been identified (see WARNINGS, PRECAUTIONS and ADVERSE REACTIONS). HYPOTENSION Tizanidine is a α2-adrenergic agonist (like clonidine) and can produce hypotension.
In a single dose study where blood pressure was monitored closely after dosing, two-thirds of patients treated with 8 mg of tizanidine had a 20% reduction in either the diastolic or systolic BP. The reduction was seen within 1 hour after dosing, peaked 2 to 3 hours after dosing and was associated, at times, with bradycardia, orthostatic hypotension, lightheadedness/dizziness and rarely syncope. The hypotensive effect is dose related and has been measured following single doses of ≥ 2 mg.
The chance of significant hypotension may possibly be minimized by titration of the dose and by focusing attention on signs and symptoms of hypotension prior to dose advancement. In addition, patients moving from a supine to a fixed upright position may be at increased risk for hypotension and orthostatic effects. Caution is advised when tizanidine is to be used in patients receiving concurrent antihypertensive therapy and should not be used with other α2-adrenergic agonists.
Clinically significant hypotension (decreases in both systolic and diastolic pressure) has been reported with concomitant administration of either fluvoxamine or ciprofloxacin and single doses of 4 mg of tizanidine. Therefore, concomitant use of tizanidine with fluvoxamine or with ciprofloxacin, potent inhibitors of CYP1A2, is contraindicated (see CONTRAINDICATIONS and CLINICAL PHARMACOLOGY: Drug Interactions). RISK OF LIVER INJURY Tizanidine occasionally causes liver injury, most often hepatocellular in type.
In controlled clinical studies, approximately 5% of patients treated with tizanidine had elevations of liver function tests (ALT/SGPT, AST/SGOT) to greater than 3 times the upper limit of normal (or 2 times if baseline levels were elevated) compared to 0.4% in the control patients. Most cases resolved rapidly upon drug withdrawal with no reported residual problems. In occasional symptomatic cases, nausea, vomiting, anorexia and jaundice have been reported.
Based upon postmarketing experience, death associated with liver failure has been a rare occurrence reported in patients treated with tizanidine. Monitoring of aminotransferase levels is recommended during the first 6 months of treatment (e.g., baseline, 1, 3 and 6 months) and periodically thereafter, based on clinical status. Because of the potential toxic hepatic effect of tizanidine, the drug should ordinarily be avoided or used with extreme caution in patients with impaired hepatic function.
SEDATION In the multiple doses, controlled clinical studies, 48% of patients receiving any dose of tizanidine reported sedation as an adverse event. In 10% of these cases, the sedation was rated as severe compared to < 1% in the placebo treated patients. Sedation may interfere with everyday activity.
The effect appears to be dose related. In a single dose study, 92% of the patients receiving 16 mg, when asked, reported that they were drowsy during the 6 hour study. This compares to 76% of the patients on 8 mg and 35% of the patients on placebo.
Patients began noting this effect 30 minutes following dosing. The ef…
🤒 Adverse Reactions ▾
ADVERSE REACTIONS SECTION In multiple doses, placebo-controlled clinical studies, 264 patients were treated with tizanidine and 261 with placebo. Adverse events, including severe adverse events, were more frequently reported with tizanidine than with placebo. COMMON ADVERSE EVENTS LEADING TO DISCONTINUATION Forty-five of 264 (17%) patients receiving tizanidine and 13 of 261 (5%) of patients receiving placebo in three multiple dose, placebo-controlled clinical studies, discontinued treatment for adverse events.
When patients withdrew from the study, they frequently had more than one reason for discontinuing. The adverse events most frequently leading to withdrawal of tizanidine treated patients in the controlled clinical studies were asthenia (weakness, fatigue and/or tiredness) (3%), somnolence (3%), dry mouth (3%), increased spasm or tone (2%), and dizziness (2%). MOST FREQUENT ADVERSE CLINICAL EVENTS SEEN IN ASSOCIATION WITH THE USE OF TIZANIDINE In multiple dose, placebo-controlled clinical studies involving 264 patients with spasticity, the most frequent adverse effects were dry mouth, somnolence/sedation, asthenia (weakness, fatigue and/or tiredness) and dizziness.
Three-quarters of the patients rated the events as mild to moderate and one-quarter of the patients rated the events as being severe. These events appeared to be dose related. ADVERSE EVENTS REPORTED IN CONTROLLED STUDIES The events cited reflect experience gained under closely monitored conditions of clinical studies in a highly selected patient population.
In actual clinical practice or in other clinical studies, these frequency estimates may not apply, as the conditions of use, reporting behavior, and the kinds of patients treated may differ. Table 1 lists treatment emergent signs and symptoms that were reported in greater than 2% of patients in three multiple dose, placebo-controlled studies who received tizanidine where the frequency in the tizanidine group was at least as common as in the placebo group. These events are not necessarily related to tizanidine treatment.
For comparison purposes, the corresponding frequency of the event (per 100 patients) among placebo treated patients is also provided. Table 1: Multiple Dose, Placebo-Controlled Studies—Frequent (> 2%) Adverse Events Reported for Which Tizanidine Tablets Incidence is Greater than Placebo * (weakness, fatigue, and/or tiredness) Event Placebo N = 261 % Tizanidine Tablet N = 264 % Dry mouth 10 49 Somnolence 10 48 Asthenia* 16 41 Dizziness 4 16 UTI 7 10 Infection 5 6 Constipation 1 4 Liver function tests abnormal <1 3 Vomiting 0 3 Speech disorder 0 3 Amblyopia (blurred vision) <1 3 Urinary frequency 2 3 Flu symptom 2 3 SGPT/ALT increased <1 3 Dyskinesia 0 3 Nervousness <1 3 Pharyngitis 1 3 Rhinitis 2 3 Close
🆘 Overdosage ▾
OVERDOSAGE SECTION A review of the safety surveillance database revealed cases of intentional and accidental tizanidine overdose. Some of the cases resulted in fatality and many of the intentional overdoses were with multiple drugs including CNS depressants. The clinical manifestations of tizanidine overdose were consistent with its known pharmacology.
In the majority of cases a decrease in sensorium was observed including lethargy, somnolence, confusion and coma. Depressed cardiac function are also observed including most often bradycardia and hypotension. Respiratory depression is another common feature of tizanidine overdose.
Should overdose occur, basic steps to ensure the adequacy of an airway and the monitoring of cardiovascular and respiratory systems should be undertaken. In general, symptoms resolve within one to three days following discontinuation of tizanidine and administration of appropriate therapy. Due to the similar mechanism of action, symptoms and management of tizanidine overdose are similar to those following clonidine overdose.
For the most recent information concerning the management of overdose, contact a poison control center.
🧬 Clinical Pharmacology ▾
CLINICAL PHARMACOLOGY SECTION Mechanism Of Action Tizanidine is an agonist at α2-adrenergic receptor sites and presumably reduces spasticity by increasing presynaptic inhibition of motor neurons. In animal models, tizanidine has no direct effect on skeletal muscle fibers or the neuromuscular junction, and no major effect on monosynaptic spinal reflexes. The effects of tizanidine are greatest on polysynaptic pathways.
The overall effect of these actions is thought to reduce facilitation of spinal motor neurons. The imidazoline chemical structure of tizanidine is related to that of the anti-hypertensive drug clonidine and other α2-adrenergic agonists. Pharmacological studies in animals show similarities between the two compounds, but tizanidine was found to have one-tenth to one-fiftieth (1/50) of the potency of clonidine in lowering blood pressure.
Pharmacokinetics Absorption and Distribution Following oral administration, tizanidine is essentially completely absorbed. The absolute oral bioavailability of tizanidine is approximately 40% (CV = 24%), due to extensive first-pass hepatic metabolism. Tizanidine is extensively distributed throughout the body with a mean steady state volume of distribution of
2.4L/kg (CV = 21%) following intravenous administration in healthy adult volunteers. Tizanidine is approximately 30% bound to plasma proteins. Pharmacokinetics, Metabolism and Excretion Tizanidine has linear pharmacokinetics over a dose of 1 to 20 mg.
Tizanidine has a half-life of approximately 2.5 hours (CV=33%). Approximately 95% of an administered dose is metabolized. The primary cytochrome P450 isoenzyme involved in tizanidine metabolism is CYP1A2.
Tizanidine metabolites are not known to be active; their half-lives range from 20 to 40 hours. Following single and multiple oral dosing of 14C-tizanidine, an average of 60% and 20% of total radioactivity was recovered in the urine and feces, respectively. Pharmacokinetic differences between Tizanidine Capsules and Tizanidine Tablets Tizanidine Capsules and Tizanidine tablets are bioequivalent to each other under fasted conditions, but not under fed conditions.
A single dose of either two 4 mg tablets or two 4 mg capsules was administered under fed and fasting conditions in an open label, four period, randomized crossover study in 96 human volunteers, of whom 81 were eligible for the statistical analysis. Following oral administration of either the tablet or capsule (in the fasted state), tizanidine has peak plasma concentrations occurring 1.0 hours after dosing with a half-life of approximately 2 hours. When two 4 mg tablets are administered with food the mean maximal plasma concentration is increased by approximately 30%, and the median time to peak plasma concentration is increased by 25 minutes, to 1 hour and 25 minutes.
In contrast, when two 4 mg capsules are administered with food the mean maximal plasma concentration is decreased by 20%, the median time to peak plasma concentration is increased by 2 hours to 3 hours. Consequently, the mean Cmax for the capsule when administered with food is approximately 2/3's the Cmax for the tablet when administered with food. Food also increases the extent of absorption for both the tablets and capsules.
The increase with the tablet (~30%) is significantly greater than with the capsule (~10%). Consequently when each is administered with food, the amount absorbed from the capsule is about 80% of the amount absorbed from the tablet (See Figure 1). Administration of the capsule contents sprinkled on applesauce is not bioequivalent to administration of an intact capsule under fasting conditions.
Administration of the capsule contents on applesauce results in a 15% - 20% increase in Cmax and AUC of tizanidine compared to administration of an intact capsule while fasting, and a 15 minute decrease in the median lag time and time to peak concentration. Figure 1: Mean Tizanidine Concentration vs. Time Profiles For Tizanidine Tablets and Capsules…
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED SECTION Tizanidine tablets USP are available as white to off-white, round, flat, beveledged uncoated tablets containing 2 mg or 4 mg of tizanidine. Tizanidine tablets USP 2 mg are debossed with "U" and "168" on one side and bisecting score on other side. Bottles of 150: NDC 29300-168-15 Bottles of 500: NDC 29300- 168-05 Bottles of 1000: NDC 29300- 168-10 Tizanidine tablets USP 4 mg are debossed with "U" and "169" on one side and quadrisecting score on other side.
Bottles of 150: NDC 29300- 169-15 Bottles of 300: NDC 29300- 169-03 Bottles of 500: NDC 29300- 169-05 Bottles of 1000: NDC 29300-169-10 Dispense in tight, light-resistant container [see USP].
📋 Description ▾
DESCRIPTION SECTION Tizanidine hydrochloride is a centrally acting α2-adrenergic agonist. Tizanidine HCl (tizanidine) is a white to off-white, fine crystalline powder, which is odorless or with a faint characteristic odor. Tizanidine is slightly soluble in water and methanol; solubility in water decreases as the pH increases.
Its chemical name is 5-chloro-4-(2-imidazolin-2-ylamino)-2,1,3-benzothiodiazole hydrochloride. Tizanidine's molecular formula is C9H8CIN5S-HCl, its molecular weight is 290.2 and its structural formula is: Tizanidine tablets USP are supplied as 2 and 4 mg tablets for oral administration. Tizanidine tablets USP are composed of the active ingredient, tizanidine hydrochloride USP (2.288 mg equivalent to 2 mg tizanidine base and 4.576 mg equivalent to 4 mg tizanidine base), and the inactive ingredients, colloidal silicon dioxide, stearic acid, microcrystalline cellulose and anhydrous lactose. image description