Home › NDC Lookup › Ingredients › Tizanidine › 76420-0866-15

Tizanidine 4 mg Tablet, 150-count

by Asclemed USA, Inc. · 150 TABLET in 1 BOTTLE (76420-866-15)

NDC 76420-0866-15

🏷️ FDA NDC (as labeled) 76420-866-15 billing pads the product segment with a zero

This package

Contains150-count Pack sizes6 compare ↓

Also priced by: Part D plans $0.1130/unit — full pricing hub ↓

Also comes in: 30 tablets 76420-0866-30 60 tablets 76420-0866-60 90 tablets 76420-0866-90 120 tablets 76420-0866-12 1000 tablets 76420-0866-00

Rx only Generic On market Non-controlled

🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm

📋 All sources & update times →

This page is curated, coded, and maintained by Dr. Brian Staiger, PharmD

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

⚠️

Other active recalls for Tizanidine (different manufacturers) — 2 · tap to view

These affect other manufacturers’ products for the same ingredient — not necessarily the exact NDC on this page.

Class II · Jun 26, 2023 — Failed Stability Specifications (Preferred Pharmaceuticals, Inc.) · FDA recall D-0894-2023

Class II · Jun 21, 2023 — Failed dissolution specification: Out of specification results observed in 24-month long term stability testing. (Dr Reddy's Laboratories Limited) · FDA recall D-0923-2023

Each entry is an official FDA enforcement report — look up any recall number in the FDA recall database ↗

🆔 Identity & classification

FDA NDC (as labeled) 76420-866-15

Product NDC 76420-866

11-digit billing NDC 76420086615

RxCUI 313412, 313413

UNII B53E3NMY5C

Application # ANDA076286

SPL Set ID 81385ce2-1d82-4987-8e18-83c823e10b99

Established class (EPC) Central alpha-2 Adrenergic Agonist

Mechanism of action Adrenergic alpha2-Agonists

DEA schedule Non-controlled

Marketing category ANDA

Marketing status On market

FDA listing status Listed (active directory)

Marketing start 2021-06-15

Route ORAL

Dosage form TABLET

Substance TIZANIDINE HYDROCHLORIDE

TE code (Orange Book) AB · RLD · RS

Why two NDCs? The FDA registers this code as 76420-866-15 — a 5-3-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the product segment → 76420-0866-15. Same drug, same package — only the format differs.

Where does this data come from?

Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Central alpha-2 Adrenergic Agonist class.

Pharmacologic class Central alpha-2 Adrenergic Agonist

Drug family (ATC) Other centrally acting agents

How it works Adrenergic alpha2-Agonists

Where does this data come from?

Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerAsclemed USA, Inc.

Application holderDR REDDYS LABORATORIES INC

FDA applicationANDA076286 (ANDA)

Labeler code76420

First marketedJun 2021

Product typeHuman Prescription Drug

Portfolio652 products on file

🔎 All NDCs from Asclemed USA, Inc.

The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).

Where does this data come from?

Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

📗 Our plain-language guide HelloPharmacist

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...

📖 Read our full Tizanidine guide →

Patient education

📘 MedlinePlus patient leaflet ↗

Supplement & herbal interactions

Some supplements/herbs that may interact with Tizanidine — tap one for details:

Activated CharcoalMajor Coffee CharcoalModerate European MandrakeModerate GlucomannanModerate Guar GumModerate Gum ArabicModerate Slippery ElmModerate TragacanthModerate

🌿 Every supplement checked against Tizanidine (143 interactions) — ranked by severity →

Where does this data come from?

Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

💊 What it looks like

Color white

ShapeOval

ImprintR;180

Size11 mm

ScoringScored — splits in 4

One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.

Where does this data come from?

Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

🧪 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.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

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.
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.
UNII ETJ7Z6XBU4
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.
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.

Where does this data come from?

Data sourced from official FDA Structured Product Labeling (SPL) via DailyMed — 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

Are inactive ingredients the same for every manufacturer?

No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.

Why might an inactive ingredient be missing?

Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.

Can inactive ingredients matter?

Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 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	$16.95 / 150 tablets

Where does this data come from?

NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 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 mg 61919-0196-30	TIZANIDINE	30 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 mgthis 76420-0866-15	Asclemed	150 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	—
Tizanidine 4 mg 85534-0030-00	HAWAII	10 tablets	—	AB	FDA listed	—
tizanidine 4 mg 68788-4159-01	Preferred	100 tablets	—	AB	FDA listed	—
Tizanidine 4 mg 84386-0024-77	Aurobindo	150 tablets	—	—	FDA listed	—

About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.

Where does this data come from?

Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

⏳ Availability & generic status

🏛️

2021

On the market since

Jun 2021

📍

2026

Currently FDA-listed

5 years listed

🔓

Generic on the market

this product is a generic

✅This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?

Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for Tizanidine — the ingredient across all brands.

Top reported reactions

Fatigue3,191

Pain3,038

Nausea3,007

Headache2,695

Fall2,309

Diarrhoea1,970

Dizziness1,915

Reporter sex

Male · 24%

Female · 76%

Unknown · 0%

Reports over time (by year) — tap or hover for the count & year

Most recent year is provisional (FAERS lags ~3 months).

Where does this data come from?

Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDC	Description	Marketing start	Status
76420-0866-00	1000 TABLET in 1 BOTTLE (76420-866-00)	2024-10-29	Active
76420-0866-12	120 TABLET in 1 BOTTLE (76420-866-12)	2024-10-29	Active
76420-0866-15 You're viewing this	150 TABLET in 1 BOTTLE (76420-866-15)	2024-10-29	Active
76420-0866-30	30 TABLET in 1 BOTTLE (76420-866-30)	2024-10-29	Active
76420-0866-60	60 TABLET in 1 BOTTLE (76420-866-60)	2024-10-29	Active
76420-0866-90	90 TABLET in 1 BOTTLE (76420-866-90)	2024-10-29	Active

You're viewing one of 6 pack sizes for this product.

Pack size FAQ

What quantity is in NDC 76420-0866-15?

NDC 76420-0866-15 is a 150-count package — 150 tablet in 1 bottle.

What is the difference between NDC 76420-0866-15 and NDC 76420-0866-30?

Both are Tizanidine 4 mg Tablet — the drug itself is identical. NDC 76420-0866-15 is the 150-count package, while NDC 76420-0866-30 is the 30 tablets package.

What NDC number is used to bill for this package of Tizanidine 4 mg Tablet?

Bill NDC 76420-0866-15 — the 11-digit billing format is 76420086615. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

🧭 About this NDC listing & data coverage

Finished prescription product

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.

“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?

The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.

Is the NDC printed on the package the same as the 11-digit billing NDC?

Yes, they identify this exact package in different formats. The FDA registers it as 76420-866-15, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 76420-0866-15, written without dashes as 76420086615. The Identity section at the top of this page lists every form of this code.

What do the three segments of this NDC mean?

In 76420-0866-15, the first segment (76420) is the labeler code FDA assigned to Asclemed USA, Inc.; the middle segment (0866) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (15) identifies this exact package size and type. Together they name one specific package of one specific product.

Is this package still being marketed?

Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Asclemed USA, Inc.. Listing status can change — the directory data on this page refreshes weekly.

Does this product come in other package sizes?

Yes — the FDA directory lists 5 other package presentations of this same product, including 30 tablets (76420-0866-30), 60 tablets (76420-0866-60), 90 tablets (76420-0866-90). Each has its own NDC and its own page — see the package list near the top of this page.

Who lists this product with the FDA?

Asclemed USA, Inc. is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.

Do I need a prescription for this product?

This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.

This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.

Where does this data come from?

Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.

🎯 Indications and Usage ⏱️ Dosage and Administration 💊 Dosage Forms and Strengths ⛔ Contraindications ⚠️ Warnings and Cautions 🤒 Adverse Reactions 🔄 Drug Interactions 👥 Use in Specific Populations 🤰 Pregnancy 🧒 Pediatric Use 🧓 Geriatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 🧬 Mechanism of Action 📦 How Supplied / Storage and Handling 📋 Description 💬 Information for Patients

🎯 Indications and Usage 95 words ▾

1 INDICATIONS AND USAGE Tizanidine tablet is a central alpha-2-adrenergic agonist indicated for the management of spasticity. Because of the short duration of therapeutic effect, treatment with tizanidine tablets should be reserved for those daily activities and times when relief of spasticity is most important [see Dosage and Administration ( 2.1 ) ]. Tizanidine tablet is a central alpha-2-adrenergic agonist indicated for the management of spasticity.

Because of the short duration of therapeutic effect, treatment with tizanidine tablet should be reserved for those daily activities and times when relief of spasticity is most important. (1)

⏱️ Dosage and Administration ~3 min read ▾

2 DOSAGE AND ADMINISTRATION Recommended starting dose: 2 mg; dose can be repeated at 6 to 8 hourintervals, up to a maximum of 3 doses in 24 hours (2.1) Dosage can be increased by 2 mg to 4 mg per dose, with 1 to 4 daysbetween increases; total daily dose should not exceed 36 mg (2.1) Tizanidine pharmacokinetics differs between tablets and capsules, andwhen taken with or without food. These differences could result in achange in tolerability and control of symptoms ( 2.1 , 12.3 ) To discontinue tizanidine tablet, decrease dose slowly to minimize the risk of withdrawal and rebound hypertension, tachycardia, and hypertonia ( 2.2 )

2.1Dosing Information Tizanidine tablets may be prescribed with or without food. Once the formulation has been selected and the decision to take with or without food has been made, this regimen should not be altered. Food has complex effects on tizanidine pharmacokinetics, which differ with the different formulations.

Tizanidine capsules and tizanidine tablets are bioequivalent to each other under fasting conditions (more than 3 hours after a meal), but not under fed conditions (within 30 minutes of a meal). These pharmacokinetic differences may result in clinically significant differences when switching administration of tablet and capsules and when switching administration between the fed or fasted state. These changes may result in increased adverse events, or delayed or 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 ( 12.3 ) ]. The recommended starting dose is 2 mg. Because the effect of tizanidine tablets peaks at approximately 1 to 2 hours post-dose and dissipates between 3 to 6 hours post-dose, treatment can be repeated at 6 to 8 hour intervals, as needed, to a maximum of three doses in 24 hours.

Dosage can be gradually increased by 2 mg to 4 mg at each dose, with 1 to 4 days between dosage increases, until a satisfactory reduction of muscle tone is achieved. The total daily dose should not exceed 36 mg. Single doses greater than 16 mg have not been studied.

2.2Dosing in Patients with Renal Impairment Tizanidine tablets should be used with caution in patients with renal insufficiency (creatinine clearance < 25 mL/min), as clearance is reduced by more than 50%. In these, patients, during titration, the individual doses should be reduced. If higher doses are required, individual doses rather than dosing frequency should be increased [see Warnings and Precautions ( 5.7 ) ].

2.3Dosing in Patients with Hepatic Impairment Tizanidine tablets should be used with caution in patients with any hepatic impairment. In these patients, during titration, the individual doses should be reduced. If higher doses are required, individual doses rather than dosing frequency should be increased.

Monitoring of aminotransferase levels is recommended for baseline and 1 month after maximum dose is achieved, or if hepatic injury is suspected. [see Use in Specific Populations ( 8.7 ) ]

2.4Drug Discontinuation If therapy needs to be discontinued, particularly in patients who have been receiving high doses (20 mg to 36 mg daily) for long periods (9 weeks or more) or who may be on concomitant treatment with narcotics, the dose should be decreased slowly (2 mg to 4 mg per day) to minimize the risk of withdrawal and rebound hypertension, tachycardia, and hypertonia [see Drug Abuse and Dependence ( 9.3 ) ].

💊 Dosage Forms and Strengths 67 words ▾

3 DOSAGE FORMS AND STRENGTHS Tablets Tizanidine Tablets USP, 2 mg are white to off white, oval, flat, beveled edged tablets debossed with “R179” on one side and “bisecting score” on other side. Tizanidine Tablets USP, 4 mg are white to off white, oval, flat, beveled edged tablets debossed with “R180” on one side and “quadrisecting score” on other side. Tablets 2 mg & 4 mg (3)

⛔ Contraindications 48 words ▾

4 CONTRAINDICATIONS Tizanidine hydrochloride is contraindicated in patients taking potent inhibitors of CYP1A2, such as fluvoxamine or ciprofloxacin [see Drug Interactions ( 7.1 , 7.2 ) ]. Concomitant use with potent inhibitors of CYP1A2, such as fluvoxamine or ciprofloxacin ( 4 , 5.5 , 7.1 , 7.2 )

⚠️ Warnings and Cautions ~3 min read ▾

5 WARNINGS AND PRECAUTIONS Hypotension: monitor for signs and symptoms of hypotension, in particular in patients receiving concurrent antihypertensives; tizanidine hydrochloride should not be used with other α 2 -adrenergic agonists ( 5.1 , 7.7 ) Risk of liver injury: monitor ALTs; discontinue tizanidine hydrochloride if liver injury occurs ( 5.2 ) Sedation: tizanidine hydrochloride may interfere with everyday activities; sedative effects of tizanidine hydrochloride, alcohol, and other CNS depressants are additive ( 5.3 , 7.5 , 7.6 ) Hallucinations: consider discontinuation of tizanidine hydrochloride ( 5.4 ) Less potent inhibitors of CYP1A2: may cause hypotension, bradycardia, or excessive drowsiness, use caution if tizanidine hydrochloride is used with less potent inhibitors of CYP1A2, e.g., zileuton, other fluoroquinolones, antiarrythmics , cimetidine, famotidine, oral contraceptives, acyclovir, and ticlopidine ( 5.5 , 7.3 , 12.3 ) Renal impairment (creatinine clearance < 25 mL/min): use tizanidine hydrochloride with caution, and monitor closely for dry mouth, somnolence, asthenia and dizziness as indicators of potential overdose ( 5.7 )

5.1Hypotension Tizanidine is an α 2 -adrenergic agonist that can produce hypotension. Syncope has been reported in the post marketing setting. 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 fixed upright position may be at increased risk for hypotension and orthostatic effects. Monitor for hypotension when tizanidine hydrochloride is used in patients receiving concurrent antihypertensive therapy. It is not recommended that tizanidine hydrochloride be used with other α 2 -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 hydrochloride. Therefore, concomitant use of tizanidine hydrochloride with fluvoxamine or with ciprofloxacin, potent inhibitors of CYP1A2, is contraindicated [see Contraindications (4 ) and Drug Interactions ( 7.1 , 7.2) ].

5.2Risk of Liver Injury Tizanidine hydrochloride may cause hepatocellular liver injury. Tizanidine hydrochloride should be used with caution in patients with any hepatic impairment. Monitoring of aminotransferase levels is recommended for baseline and 1 month after maximum dose is achieved, or if hepatic injury is suspected. [see Dosage and Administration ( 2.3 ) and Use in Specific Populations (8.7 ) ]

5.3Sedation Tizanidine hydrochloride can cause sedation, which may interfere with everyday activity. In the multiple dose studies, the prevalence of patients with sedation peaked following the first week of titration and then remained stable for the duration of the maintenance phase of the study. The CNS depressant effects of tizanidine hydrochloride with alcohol and other CNS depressants (e.g., benzodiazepines, opioids, tricyclic antidepressants) may be additive.

Monitor patients who take tizanidine hydrochloride with another CNS depressant for symptoms of excess sedation. [see Drug Interactions ( 7.5 , 7.6 )]

5.4Hallucinosis/Psychotic-Like Symptoms Tizanidine hydrochloride use has been associated with hallucinations. Formed, visual hallucinations or delusions have been reported in 5 of 170 patients (3%) in two North American controlled clinical studies. Most of the patients were aware that the events were unreal.

One patient developed psychosis in association with the hallucinations. One patient among these 5 continued to have problems for at least 2 weeks following discontinuation of tizanidine. Consider discontinuing tizanidine hydrochloride in patients who develop hallucinations.

5.5Interaction with CYP1A2 Inhibitors Because of potential drug interactions, tizanidine hydrochloride is contr…

🤒 Adverse Reactions ~3 min read ▾

6 ADVERSE REACTIONS The following adverse reactions are described elsewhere in other sections of the prescribing information: Hypotension [see Warnings and Precautions ( 5.1 ) ] Liver Injury [see Warnings and Precautions ( 5.2 ) ] Sedation [see Warnings and Precautions ( 5.3 ) ] Hallucinosis/Psychotic-Like Symptoms [see Warnings and Precautions ( 5.4 ) ] Hypersensitivity Reactions [see Warnings and Precautions ( 5.6 ) ] The most common adverse reactions (greater than 2% of 264 patients taking tizanidine and greater than in placebo-treated patients in three multiple dose, placebo-controlled studies) were dry mouth, somnolence, asthenia, dizziness, urinary tract infection, constipation, liver function tests abnormal, vomiting,speech disorder, amblyopia, urinary frequency, flu syndrome, SGPT/ALT increased, dyskinesia, nervousness, pharyngitis, and rhinitis ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact NorthStar RxLLC at 1-800-206-7821 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in clinical practice. Three double-blind, randomized, placebo controlled -clinical studies were conducted to evaluate the effect of tizanidine on spasticity control. Two studies were conducted in patients with multiple sclerosis and one in patients with spinal cord injury.

Each study had a 13-week active treatment period which included a 3-week titration phase to the maximum tolerated dose up to 36 mg/day in three divided doses, a 9-week plateau phase where the dose of tizanidine was held constant and a 1- week dose tapering. In all, 264 patients received tizanidine and 261 patients received placebo. Across the three studies patient ages ranged from 15 to 69 years and 51.4 percent were women.

The median dose during the plateau phase ranged from 20 to 28 mg/day. The most frequent adverse reactions reported in multiple dose, placebo-controlled clinical studies involving 264 patients with spasticity 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. Table 1 lists signs and symptoms that were reported in greater than 2% of patients in three multiple dose, placebo-controlled studies who received tizanidine hydrochloride where the frequency in the tizanidine hydrochloride group was greater than the placebo group. 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 Reactions Reported for Which Tizanidine Tablets Incidence is Greater than Placebo 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 test abnormality 2 6 Vomiting 0 3 Speech disorder 0 3 Amblyopia (blurred vision) <1 3 Urinary frequency 2 3 Flu syndrome 2 3 Dyskinesia 0 3 Nervousness <1 3 Pharyngitis 1 3 Rhinitis 2 3 *(weakness, fatigue, and/or tiredness) In the single dose, placebo-controlled study involving 142 patients with spasticity due to multiple sclerosis (Study 1) [see Clinical Studies ( 14 ) ], the patients were specifically asked if they had experienced any of the four most common adverse reactions: dry mouth, somnolence (drowsiness), asthenia (weakness, fatigue and/or tiredness) and dizziness.

In addition, hypotension and bradycardia were observed. The occurrence of these reactions is summarized in Table 2. Other events were, in general, reported at a rate of 2% or less.

Table 2: Single Dose, Placebo-Controlled Stud…

🔄 Drug Interactions ~2 min read ▾

7 DRUG INTERACTIONS

7.1Fluvoxamine Concomitant use of fluvoxamine and tizanidine hydrochloride is contraindicated. Changes in pharmacokinetics of tizanidine when administered with fluvoxamine resulted in significantly decreased blood pressure, increased drowsiness, and increased psychomotor impairment. [see Contraindications (4) and Clinical Pharmacology ( 12.3 ) ]

7.2Ciprofloxacin Concomitant use of ciprofoxacin and tizanidine hydrochloride is contraindicated. Changes in pharmacokinetics of tizanidine when administered with ciprofloxacin resulted in significantly decreased blood pressure, increased drowsiness, and increased psychomotor impairment [See Contraindications (4) and Clinical Pharmacology ( 12.3 ) ]

7.3CYP1A2 Inhibitors other than Fluvoxamine and Ciprofloxacin Because of potential drug interactions, concomitant use of tizanidine hydrochloride with other CYP1A2 inhibitors, such as zileuton, fluoroquinolones other than strong CYP1A2 inhibitors (which are contraindicated), antiarrythmics (amiodarone, mexiletine, propafenone, and verapamil), cimetidine, famotidine, oral contraceptives, acyclovir, and ticlopidine) should be avoided. If their use is clinically necessary, therapy should be initiated with 2 mg dose and increased in 2 to 4 mg steps daily based on patient response to therapy.

If adverse reactions such as hypotension, bradycardia, or excessive drowsiness occur, reduce or discontinue tizanidine hydrochloride therapy. [see Warnings and Precautions ( 5.5 ) and Clinical Pharmacology ( 12.3 ) ]

7.4Oral Contraceptives Concomitant use of tizanidine hydrochloride with oral contraceptives is not recommended. However, if concomitant use is clinically necessary, initiate tizanidine hydrochloride with a single 2 mg dose and increase in 2 to 4 mg steps daily based on patient response to therapy. If adverse reactions such as hypotension, bradycardia, or excessive drowsiness occur, reduce or discontinue tizanidine hydrochloride therapy. [see Clinical Pharmacology ( 12.3 ) ]

7.5Alcohol Alcohol increases the overall amount of drug in the bloodstream after a dose of tizanidine hydrochloride. This was associated with an increase in adverse reactions of tizanidine hydrochloride. The CNS depressant effects of tizanidine hydrochloride and alcohol are additive. [see Clinical Pharmacology ( 12.3 ) ]

7.6Other CNS Depressants The sedative effects of tizanidine hydrochloride with CNS depressants (e.g., benzodiazepines, opioids, tricyclic antidepressants) may be additive. Monitor patients who take tizanidine hydrochloride with another CNS depressant for symptoms of excess sedation. [see Clinical Pharmacology ( 12.3 ) ] 7.7 α 2 -adrenergic agonists Because hypotensive effects may be cumulative, it is not recommended that tizanidine hydrochloride be used with other α 2 -adrenergic agonists. [see Warnings and Precautions ( 5.1 ) ]

👥 Use in Specific Populations ~3 min read ▾

8 USE IN SPECIFIC POPULATIONS Pregnancy: Based on animal data, may cause fetal harm (8.1) Geriatric use: tizanidine hydrochloride should be used with caution in elderly patients because clearance is decreased four-fold (8.5)

8.1Pregnancy Pregnancy Category C Tizanidine hydrochloride has not been studied in pregnant women. Tizanidine hydrochloride should be given to pregnant women only if the benefit outweighs the risk to the unborn fetus. Reproduction studies performed in rats at a dose of 3 mg/kg, equal to the maximum recommended human dose on a mg/m 2 basis, and in rabbits at 30 mg/kg, 16 times the maximum recommended human dose on a mg/m 2 basis, did not show evidence of teratogenicity.

Tizanidine at doses that are equal to and up to 8 times the maximum recommended human dose on a mg/m 2 basis increased gestation duration in rats. Prenatal and postnatal pup loss was increased and developmental retardation occurred. Post-implantation loss was increased in rabbits at doses of 1 mg/kg or greater, equal to or greater than 0.5 times the maximum recommended human dose on a mg/m 2 basis.

8.3Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when tizanidine hydrochloride is administered to a nursing woman.

8.4Pediatric Use Safety and effectiveness in pediatric patients have not been established.

8.5Geriatric Use Tizanidine hydrochloride is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. Clinical studies of tizanidine hydrochloride did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently than younger subjects.

Cross-study comparison of pharmacokinetic data following single dose administration of 6 mg tizanidine hydrochloride showed that younger subjects cleared the drug four times faster than the elderly subjects. In elderly patients with renal insufficiency (creatinine clearance <25 mL/min), tizanidine clearance is reduced by more than 50% compared to healthy elderly subjects; this would be expected to lead to a longer duration of clinical effect. During titration, the individual doses should be reduced.

If higher doses are required, individual doses rather than dosing frequency should be increased. Monitor elderly patients because they may have an increased risk for adverse reactions associated with tizanidine hydrochloride.

8.6Impaired Renal Function Tizanidine hydrochloride is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. In patients with renal insufficiency (creatinine clearance < 25 mL/min) clearance was reduced by more than 50%. In these patients, during titration, the individual doses should be reduced.

If higher doses are required, individual doses rather than dosing frequency should be increased. These patients should be monitored closely for the onset or increase in severity of the common adverse events (dry mouth, somnolence, asthenia and dizziness) as indicators of potential overdose. [see Dosage and Administration ( 2.2 ), Warnings and Precautions (5.7 ) and Clinical Pharmacology ( 12.3 )]

8.7Impaired Hepatic Function The influence of hepatic impairment on the pharmacokinetics of tizanidine has not been evaluated. Because tizanidine is extensively metabolized in the liver, hepatic impairment would be expected to have significant effects on pharmacokinetics of tizanidine. [see Dosing and Administration (2.3) , Warnings and Precautions ( 5.2 ), and Clinical Pharmacology ( 12.3 ) ].

🤰 Pregnancy 148 words ▾

🧒 Pediatric Use 13 words ▾

8.4Pediatric Use Safety and effectiveness in pediatric patients have not been established.

🧓 Geriatric Use 187 words ▾

🆘 Overdosage 194 words ▾

10 OVERDOSAGE A review of the safety surveillance database revealed cases of intentional and accidental tizanidine hydrochloride 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 is 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. Tizanidine is a lipid-soluble drug, which is only slightly soluble in water and methanol. Therefore, dialysis is not likely to be an efficient method of removing drug from the body.

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 that following clonidine overdose. For the most recent information concerning the management of overdose, contact a poison control center.

🧬 Clinical Pharmacology ~3 min read ▾

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action Tizanidine is a central alpha-2-adrenergic receptor agonist and presumably reduces spasticity by increasing presynaptic inhibition of motor neurons. The effects of tizanidine are greatest on polysynaptic pathways. The overall effect of these actions is thought to reduce facilitation of spinal motor neurons.

12.3Pharmacokinetics 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. Differences between Tizanidine Capsules and Tizanidine Tablets Tizanidine capsules and tizanidine tablets are bioequivalent to each other under fasting 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), peak plasma concentrations of tizanidine occurred 1 hours after dosing with a half-life of approximately 2 hours. When two 4 mg tablets were administered with food, the mean maximal plasma concentration was increased by approximately 30%, and the median time to peak plasma concentration was increased by 25 minutes, to 1 hour and 25 minutes.

In contrast, when two 4 mg capsules were administered with food, the mean maximal plasma concentration was decreased by 20%, the median time to peak plasma concentration was increased 2 to 3 hours. Consequently, the mean C max for the capsule when administered with food is approximately 66% the C max for the tablet when administered with food. Food also increased the extent of absorption for both the tablets and capsules.

The increase with the tablet (~30%) was significantly greater than with the capsule (~10%). Consequently when each was administered with food, the amount absorbed from the capsule was about 80% of the amount absorbed from the tablet. Administration of the capsule contents sprinkled on applesauce was not bioequivalent to administration of an intact capsule under fasting conditions.

Administration of the capsule contents on applesauce resulted in a 15% to 20% increase in C max and AUC of tizanidine and a 15 minute decrease in the median lag time and time to peak concentration compared to administration of an intact capsule while fasting. Figure 1: Mean Tizanidine Concentration vs. Time Profiles For Tizanidine Tablets and Capsules (2 × 4 mg) Under Fasted and Fed Conditions Metabolism and Excretion Tizanidine has linear pharmacokinetics over the doses studied in clinical development (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 14 C-tizanidine, an average of 60% and 20% of total radioactivity was recovered in the urine and feces, respectively. Special Populations Age Effects No specific pharmacokinetic study was conducted to investigate age effects.

Cross study comparison of pharmacokinetic data following single dose administration of 6 mg tizanidine hydrochloride showed that younger subjects cleared the drug four times faster than the elderly subjects. Tizanidine hydrochloride has not been evaluated in children. [see Use in Specific Populations ( 8.4 , 8.5 ) ] Hepatic Impairment The influence of hep…

🧬 Mechanism of Action 46 words ▾

📦 How Supplied / Storage and Handling 203 words ▾

16 HOW SUPPLIED/STORAGE AND HANDLING

16.2Tizanidine Tablets Tizanidine Tablets USP, 2 mgare white to off white, oval, flat, beveled edged tablets debossed with “R179” on one side and “bisecting score” on other side. The tablets are available in bottle of 150. Bottles of 30 NDC 76420-865-30 (repackaged from NDC 16714-171-XX) Bottles of 60 NDC 76420-865-60 (repackaged from NDC 16714-171-XX) Bottles of 90 NDC 76420-865-90 (repackaged from NDC 16714-171-XX) Bottles of 120 NDC 76420-865-12 (repackaged from NDC 16714-171-XX) Bottles of 150 NDC 76420-865-15 (relabeled from NDC 16714-171-01) Tizanidine Tablets USP, 4 mg are white to off white, oval, flat, beveled edged tablets debossed with “R180” on one side and “quadrisecting score” on other side.

The tablets are available in bottles of 150 and 1000. Bottles of 30 NDC 76420-866-30 (repackaged from NDC 16714-172-XX) Bottles of 60 NDC 76420-866-60 (repackaged from NDC 16714-172-XX) Bottles of 90 NDC 76420-866-90 (repackaged from NDC 16714-172-XX) Bottles of 120 NDC 76420-866-12 (repackaged from NDC 16714-172-XX) Bottles of 150 NDC 76420-866-15 (relabeled from NDC 16714-172-01) Bottles of 1000 NDC 76420-866-00 (relabeled from NDC 16714-172-02) Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature].

Dispense in containers with child resistant closure.

📋 Description 115 words ▾

11 DESCRIPTION Tizanidine hydrochloride USP, is a central α 2 -adrenergic agonist. Tizanidine hydrochloride USP is almost white to slightly yellow crystalline powder, which is slightly soluble in water and methanol. Its chemical name is 5-chloro-4-(2-imidazolin-2-ylamino)-2,1,3-benzothiodiazole monohydrochloride.

Tizanidine’s molecular formula is C 9 H 8 ClN 5 S.HCl, its molecular weight is 290.2 and its structural formula is: Tizanidine tablets USP, are supplied as 2 mg and 4 mg tablets for oral administration. Tizanidine tablets USP, contain 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, anhydrous lactose, microcrystalline cellulose, colloidal silicon dioxide and stearic acid. structure

💬 Information for Patients ~1 min read ▾

17 PATIENT COUNSELING INFORMATION Serious Drug Interactions Advise patients they should not take tizanidine hydrochloride if they are taking fluvoxamine or ciprofloxacin because of the increased risk of serious adverse reactions including severe lowering of blood pressure and sedation. Instruct patients to inform their physicians or pharmacists when they start or stop taking any medication because of the risks associated with interaction between tizanidine hydrochloride and other medicines. Tizanidine hydrochloride Dosing Tell patients to take tizanidine hydrochloride exactly as prescribed (consistently either with or without food) and not to switch between tablets and capsules.

Inform patients that they should not take more tizanidine hydrochloride than prescribed because of the risk of adverse events at single doses greater than 8 mg or total daily doses greater than 36 mg. Tell patients that they should not suddenly discontinue tizanidine hydrochloride, because rebound hypertension and tachycardia may occur. Effects of Tizanidine Hydrochloride Warn patients that they may experience hypotension and to be careful when changing from a lying or sitting to a standing position.

Tell patients that tizanidine hydrochloride may cause them to become sedated or somnolent and they should be careful when performing activities that require alertness, such as driving a vehicle or operating machinery. Tell patients that the sedation may be additive when tizanidine hydrochloride is taken in conjunction with drugs (baclofen, benzodiazepines) or substances (e.g., alcohol) that act as CNS depressants. Remind patients that if they depend on their spasticity to sustain posture and balance in locomotion, or whenever spasticity is utilized to obtain increased function, that Tizanidine hydrochloride decreases spasticity and caution should be used.

Relabeled and Repackaged by: Enovachem PHARMACEUTICALS Torrance, CA 90501

Glossary — plain-language definitions of medical terms used in this label:

contraindicated: Should not be used in that situation, because the risk is considered too high.

sedative: A substance with a calming effect that can also cause drowsiness.

Absorption: How a medicine moves from where it is taken, such as the stomach or gut, into the bloodstream.

abuse: Using a medicine in a way it was not meant to be used, such as taking more than prescribed to feel a high.

Active ingredient: The part of a medicine that produces its intended effect on the body.

adverse reaction: An unwanted or harmful effect that a medicine causes in the body.

Adverse Reactions: Unwanted or harmful effects that people experienced while taking a medicine, listed on its official label.

agonist: A substance that switches on a specific target in the body to produce an effect, the way a key turns a lock.

ALT: A liver enzyme (alanine aminotransferase) checked by a blood test; raised levels can signal that the liver is irritated or damaged.

asthenia: Unusual weakness or lack of physical strength and energy.

AUC: A measure of total drug exposure over time, showing how much medicine the blood is exposed to overall.

baseline: A person's starting condition, measured before treatment begins, used to see how much they change later on.

Bioavailability: The share of a dose that actually reaches the bloodstream and is able to have an effect.

bradycardia: A slower-than-normal heart rate, usually under 60 beats per minute.

clearance: How quickly the body removes a medicine from the blood, usually through the liver and kidneys.

Clinical Pharmacology: The label section explaining how a medicine works in the body and how the body processes it.

Clinical Studies: The label section summarizing the research trials used to show that a medicine works and is acceptably safe.

constipation: Having bowel movements less often than usual, or passing stools that are hard, dry, and difficult to move.

Contraindications: A list of situations or health conditions in which a medicine should not be used because the chance of harm is too high.

creatinine clearance: An estimate of how fast the kidneys filter waste from the blood, often used to choose the right medicine dose.

crossover: A study design in which each person takes one treatment for a time, then switches to the other, acting as their own comparison.

CYP1A2: A liver enzyme that breaks down certain medicines and whose activity can be changed by cigarette smoke.

cytochrome P450: A large family of enzymes, mostly in the liver, that break down many medicines so the body can remove them.

depression: A lasting low mood with loss of interest that affects everyday life.

Distribution: How a medicine spreads from the blood into the body's tissues and organs after it is absorbed.

Dosage and Administration: The label section explaining how much of a medicine to use and how to take or give it.

double-blind: A study in which neither the patients nor their doctors know who is getting the real medicine and who is getting the dummy.

Drug Abuse and Dependence: A label section describing a medicine's potential to be misused and to cause the body to rely on it.

Drug Interactions: The label section listing other medicines, foods, or substances that can change how a medicine works or raise the chance of side effects.

dyskinesia: Involuntary, uncontrolled movements of the face, arms, legs, or body.

Excretion: How the body removes a medicine or its leftover pieces, mainly through the urine or stool.

fetal harm: Injury or damage to a developing baby while it is growing inside the womb.

Half-life: The time it takes for the amount of medicine in the blood to drop by half.

hepatic impairment: Reduced liver function, meaning the liver does not work as well as normal at processing substances, including medicines.

hepatic metabolism: The breakdown of a medicine by the liver into other substances the body can use or remove.

How Supplied/Storage and Handling: The label section describing the forms and strengths a medicine comes in and how to store it properly.

hypersensitivity: An overreaction of the body's defense system to a substance, causing symptoms such as rash, swelling, or trouble breathing.

hypertension: Blood pressure that stays higher than normal, commonly called high blood pressure.

hypotension: Blood pressure that is lower than normal, which can cause dizziness or fainting.

incidence: How often a new event, such as a side effect, happens in a group of people over a set period of time.

Indications and Usage: The label section stating which medical conditions the FDA has officially approved the medicine to treat, prevent, or manage.

intravenous: Given directly into a vein through a needle or thin tube; often written as IV.

lethargy: A state of tiredness and sluggishness, often with slowed thinking or movement.

linear pharmacokinetics: When blood levels of a medicine rise in direct proportion to the size of the dose.

liver function tests: Blood tests that check how well the liver is working and whether it is irritated or damaged.

maximum tolerated dose: The highest dose people can take in a study without unacceptable side effects.

Mechanism of Action: How a medicine produces its effect in the body, described at the level of cells or body chemistry.

Metabolism: How the body chemically changes a medicine, usually in the liver, into other substances.

NDC: A unique number that identifies a specific medicine, its maker, strength, and package size.

Overdosage: The label section describing what can happen if too much of a medicine is taken and how it may be treated.

Patient Counseling Information: The label section telling health professionals what to explain to patients about using a medicine safely.

Pharmacokinetics: The study of how the body takes in a medicine, spreads it around, breaks it down, and removes it over time.

placebo: An inactive treatment with no real medicine in it, such as a sugar pill, used for comparison in a study.

placebo-controlled: Describes a study that compares people taking the real medicine against people taking a dummy pill with no active ingredient.

plasma concentration: The amount of medicine measured in the liquid part of the blood at a given time.

pregnancy category: An older letter rating (A, B, C, D, or X) once used to describe a medicine's possible risk during pregnancy.

Prescribing Information: The official, detailed document approved by the FDA that tells health professionals how to use a prescription medicine.

psychosis: A state of losing touch with reality, such as seeing or hearing things that are not there or holding false beliefs.

randomized: Assigned to a treatment group purely by chance, like a coin flip, so the groups being compared start out fair and similar.

rebound: The return of symptoms, sometimes worse than before, after a medicine that was controlling them is stopped.

receptor: A special docking spot on a cell that a medicine or natural body chemical attaches to in order to trigger an effect.

renal impairment: Reduced kidney function, meaning the kidneys do not filter waste and fluid from the blood as well as normal.

respiratory depression: Breathing that becomes too slow or too shallow to move enough air, so the body may not get enough oxygen.

sedation: A calm, sleepy, slowed-down state caused by a medicine that relaxes the brain and body.

somnolence: Feeling very sleepy or drowsy, with trouble staying awake during the day.

steady state: The point where the amount of medicine going in equals the amount leaving, so blood levels stay fairly even.

syncope: The medical term for fainting, a brief loss of consciousness from a temporary drop in blood flow to the brain.

tachycardia: A faster-than-normal heart rate, usually over 100 beats per minute.

titration: Slowly adjusting a medicine's dose up or down in small steps to find the amount that works best with the fewest side effects.

Use in Specific Populations: The label section describing how a medicine affects particular groups, such as pregnant people, children, or older adults.

volume of distribution: A calculated value showing how widely a medicine spreads into body tissues versus staying in the blood.

Warnings and Precautions: The label section describing serious risks to know about and safety steps to follow while using a medicine.

withdrawal: Uncomfortable physical or mental symptoms that appear when a medicine the body has gotten used to is reduced or stopped.

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗

← 76420-0865-12 · Asclemed 76420-0867-02 · Asclemed →

For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.

Tizanidine 4 mg Tablet, 150-count

🆔 Identity & classification

🏷️ RxNorm drug class

🏭 Manufacturer & labeler

🩺 Clinical

Patient education

Supplement & herbal interactions

💊 What it looks like

🧪 Inactive Ingredients / Excipients

Inactive ingredient FAQ

💲 Pricing

🔁 Therapeutic equivalents

⏳ Availability & generic status

🔬 Reported adverse events (FAERS)

Top reported reactions

Reporter sex

📦 Packaging — all sizes for this product

Pack size FAQ

🧭 About this NDC listing & data coverage

Questions about this listing

📄 Full prescribing information FDA SPL

7 DRUG INTERACTIONS

12 CLINICAL PHARMACOLOGY

16 HOW SUPPLIED/STORAGE AND HANDLING

🔗 Related NDC lookups