CHLORZOXAZONE

Main information

  • Trade name:
  • CHLORZOXAZONE - chlorzoxazone tablet
  • Composition:
  • CHLORZOXAZONE 500 mg
  • Administration route:
  • ORAL
  • Prescription type:
  • PRESCRIPTION DRUG
  • Medicine domain:
  • Humans
  • Medicine type:
  • Allopathic drug

Documents

Localization

  • Available in:
  • CHLORZOXAZONE - chlorzoxazone tablet
    United States
  • Language:
  • English

Therapeutic information

  • Therapeutic indications:
  • Chlorzoxazone is indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute, painful musculoskeletal conditions. The mode of action of this drug has not been clearly identified, but may be related to its sedative properties. Chlorzoxazone does not directly relax tense skeletal muscles in man.   Chlorzoxazone is contraindicated in patients with known intolerance to the drug.   
  • Product summary:
  • Chlorzoxazone tablets, USP are available as oblong, scored, white tablets debossed with WPI on one side and "39"-"68" on the other side and are packaged in bottles of 100 and 500. Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature]. Dispense contents with a child-resistant closure (as required) and in a tight container as defined in the USP/NF. Keep out of the reach of children. Manufactured By: Watson Pharma Private Limited Verna, Salcette Goa 403 722 INDIA Distributed By: Watson Pharma, Inc. Corona, CA 92880 USA Revised: November 2010                                                                           195609  

Status

  • Source:
  • DailyMed - NLM - National Library of Medicine
  • Authorization status:
  • Abbreviated New Drug Application
  • Authorization number:
  • 16590-478-28, 16590-478-30, 16590-478-40, 16590-478-60, 16590-478-71, 16590-478-72, 16590-478-90
  • Last update:
  • 13-06-2019

Summary of Product characteristics: dosage, interactions, side effects

CHLORZOXAZONE - chlorzoxazone tablet

STAT Rx USA LLC

----------

CHLORZOXAZONE TABLETS, USP 500 mg

Revised: November 2010

Rx only

195609

DESCRIPTION

Chlorzoxazone USP is a centrally acting skeletal muscle relaxant, available as tablets of 500 mg for

oral administration. Its chemical name is 5-Chloro-2-benzoxazolinone, and its structural formula is:

C H CINO MW 169.57

Chlorzoxazone USP is a white or practically white, practically odorless, crystalline powder.

Chlorzoxazone is slightly soluble in water; sparingly soluble in alcohol, in isopropyl alcohol, and in

methanol; soluble in solutions of alkali hydroxides and ammonia.

Chlorzoxazone tablets contain the inactive ingredients Docusate Sodium, Lactose (hydrous), Magnesium

Stearate, Microcrystalline Cellulose, Pregelatinized Starch, Sodium Benzoate, and Sodium Starch

Glycolate.

CLINICAL PHARMACOLOGY

Chlorzoxazone is a centrally-acting agent for painful musculoskeletal conditions. Data available from

animal experiments as well as human study indicate that chlorzoxazone acts primarily at the level of the

spinal cord and subcortical areas of the brain where it inhibits multisynaptic reflex arcs involved in

producing and maintaining skeletal muscle spasm of varied etiology. The clinical result is a reduction

of the skeletal muscle spasm with relief of pain and increased mobility of the involved muscles. Blood

levels of chlorzoxazone can be detected in people during the first 30 minutes and peak levels may be

reached, in the majority of the subjects, in about 1 to 2 hours after oral administration of chlorzoxazone.

Chlorzoxazone is rapidly metabolized and is excreted in the urine, primarily in a conjugated form as the

glucuronide. Less than one percent of a dose of chlorzoxazone is excreted unchanged in the urine in 24

hours.

INDICATIONS AND USAGE

Chlorzoxazone is indicated as an adjunct to rest, physical therapy, and other measures for the relief of

discomfort associated with acute, painful musculoskeletal conditions. The mode of action of this drug

has not been clearly identified, but may be related to its sedative properties. Chlorzoxazone does not

directly relax tense skeletal muscles in man.

CONTRAINDICATIONS

Chlorzoxazone is contraindicated in patients with known intolerance to the drug.

WARNINGS

Serious (including fatal) hepatocellular toxicity has been reported rarely in patients receiving

chlorzoxazone. The mechanism is unknown but appears to be idiosyncratic and unpredictable. Factors

predisposing patients to this rare event are not known. Patients should be instructed to report early signs

and/or symptoms of hepatotoxicity such as fever, rash, anorexia, nausea, vomiting, fatigue, right upper

quadrant pain, dark urine, or jaundice. Chlorzoxazone should be discontinued immediately and a

physician consulted if any of these signs or symptoms develop. Chlorzoxazone use should also be

discontinued if a patient develops abnormal liver enzymes (e.g., AST, ALT, alkaline phosphatase and

bilirubin.)

The concomitant use of alcohol or other central nervous system depressants may have an additive

effect.

Usage in Pregnancy

The safe use of chlorzoxazone has not been established with respect to the possible adverse effects

upon fetal development. Therefore, it should be used in women of childbearing potential only when, in

the judgement of the physician, the potential benefits outweigh the possible risks.

PRECAUTIONS

Chlorzoxazone should be used with caution in patients with known allergies or with a history of

allergic reactions to drugs. If a sensitivity reaction occurs such as urticaria, redness, or itching of the

skin, the drug should be stopped.

If any symptoms suggestive of liver dysfunction are observed, the drug should be discontinued.

ADVERSE REACTIONS

Chlorzoxazone containing products are usually well tolerated. It is possible in rare instances that

chlorzoxazone may have been associated with gastrointestinal bleeding. Drowsiness, dizziness,

lightheadedness, malaise, or over-stimulation may be noted by an occasional patient. Rarely, allergic-

type skin rashes, petechiae, or ecchymoses may develop during treatment. Angioneurotic edema or

anaphylactic reactions are extremely rare. There is no evidence that the drug will cause renal damage.

Rarely, a patient may note discoloration of the urine resulting from a phenolic metabolite of

chlorzoxazone. This finding is of no known clinical significance.

OVERDOSAGE

Symptoms

Initially, gastrointestinal disturbances such as nausea, vomiting or diarrhea together with drowsiness,

dizziness, lightheadedness or headache may occur. Early in the course there may be malaise or

sluggishness followed by marked loss of muscle tone, making voluntary movement impossible. The

deep tendon reflexes may be decreased or absent. The sensorium remains intact, and there is no

peripheral loss of sensation. Respiratory depression may occur with rapid, irregular respiration and

intercostal and substernal retraction. The blood pressure is lowered, but shock has not been observed.

Treatment

Gastric lavage or induction of emesis should be carried out, followed by administration of activated

charcoal. Thereafter, treatment is entirely supportive. If respirations are depressed, oxygen and

artificial respiration should be employed and a patent airway assured by use of an oropharyngeal airway

artificial respiration should be employed and a patent airway assured by use of an oropharyngeal airway

or endotracheal tube. Hypotension may be counteracted by use of dextran, plasma, concentrated albumin

or a vasopressor agent such as norepinephrine. Cholinergic drugs or analeptic drugs are of no value

and should not be used.

DOSAGE AND ADMINISTRATION

Usual Adult Dosage

One tablet three or four times daily. If adequate response is not obtained with this dose, it may be

increased to one and one-half tablets (750 mg) three or four times daily. As improvement occurs dosage

can usually be reduced.

HOW SUPPLIED

Chlorzoxazone tablets, USP are available as oblong, scored, white tablets debossed with WPI on one

side and "39"-"68" on the other side and are packaged in bottles of 100 and 500.

Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].

Dispense contents with a child-resistant closure (as required) and in a tight container as defined in the

USP/NF.

Keep out of the reach of children.

Manufactured By:

Watson Pharma Private Limited

Verna, Salcette Goa 403 722 INDIA

Distributed By:

Watson Pharma, Inc.

Corona, CA 92880 USA

Revised: November 2010 195609

PACKAGE LABEL - CHLORZOXAZONE 500 MG TABLETS

NDC 0591-3968-01

Chlorzoxazone

Tablets, USP

500 mg

Rx only

Each tablet contains: Chlorzoxazone USP, 500 mg

Usual Dosage: See package insert for full

prescribing information.

Store at 20ºC-25ºC (68º-77ºF).

[See USP Controlled Room Temperature.]

KEEP TIGHTLY CLOSED.

KEEP THIS AND ALL MEDICATIONS OUT OF THE

REACH OF CHILDREN.

Manufactured By:

Watson Pharma Private Limited

Verna, Salcette Goa 403 722 INDIA

Code No. GO/DRUGS/741 195607

Distributed By: Watson Pharma, Inc.

CHLORZOXAZONE

chlorzoxazone tablet

Product Information

Product T ype

HUMAN PRESCRIPTION DRUG

Ite m Code (Source )

NDC:16 59 0 -478 (NDC:0 59 1-39 6 8 )

Route of Administration

ORAL

Active Ingredient/Active Moiety

Ingredient Name

Basis of Strength

Stre ng th

CHLO RZO XAZO NE (UNII: H0 DE420 U8 G) (CHLORZOXAZONE - UNII:H0 DE420 U8 G)

CHLORZOXAZONE

50 0 mg

Inactive Ingredients

Ingredient Name

Stre ng th

DO CUSATE SO DIUM (UNII: F0 5Q2T2JA0 )

LACTO SE MO NO HYDRATE (UNII: EWQ57Q8 I5X)

MAGNESIUM STEARATE (UNII: 70 0 9 7M6 I30 )

CELLULO SE, MICRO CRYSTALLINE (UNII: OP1R32D6 1U)

STARCH, PREGELATINIZED CO RN (UNII: O8 232NY3SJ)

SO DIUM BENZO ATE (UNII: OJ245FE5EU)

SO DIUM STARCH GLYCO LATE TYPE A PO TATO (UNII: 58 56 J3G2A2)

Product Characteristics

STAT Rx USA LLC

Color

white

S core

2 pieces

S hap e

OVAL (OBLONG)

S iz e

17mm

Flavor

Imprint Code

WPI;39 ;6 8

Contains

Packag ing

#

Item Code

Package Description

Marketing Start Date

Marketing End Date

1

NDC:16 59 0 -478 -28

28 in 1 BOTTLE

2

NDC:16 59 0 -478 -30

30 in 1 BOTTLE

3

NDC:16 59 0 -478 -40

40 in 1 BOTTLE

4

NDC:16 59 0 -478 -6 0

6 0 in 1 BOTTLE

5

NDC:16 59 0 -478 -71

10 0 in 1 BOTTLE

6

NDC:16 59 0 -478 -72

120 in 1 BOTTLE

7

NDC:16 59 0 -478 -9 0

9 0 in 1 BOTTLE

Marketing Information

Marke ting Cate gory

Application Numbe r or Monograph Citation

Marke ting Start Date

Marke ting End Date

ANDA

ANDA0 8 9 8 59

12/23/20 0 8

Labeler -

ST AT Rx USA LLC (786036330)

Establishment

Name

Ad d re s s

ID/FEI

Busine ss Ope rations

STAT Rx USA LLC

78 6 0 36 330

relabel, repack

Revised: 9/2011