CHLORZOXAZONE

INDICATIONS AND USAGE Chlorzoxazone tablets are 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.

DOSAGE AND ADMINISTRATION Usual Adult Dosage Chlorzoxazone tablets USP, 375 mg: One tablet three or four times daily. If adequate response is not obtained with this dose, the 375 mg tablets may be increased to two tablets (750 mg) three or four times daily. As improvement occurs dosage can usually be reduced. Chlorzoxazone tablets USP, 500 mg: 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. Chlorzoxazone tablets USP, 750 mg: 1/3 tablet (250 mg) three or four times daily. Initial dosage for painful musculoskeletal conditions should be 2/3 tablet (500 mg) three or four times daily. If adequate response is not obtained with this dose, it may be increased to one tablet (750 mg) three or four times daily. As improvement occurs dosage can usually be reduced.

CONTRAINDICATIONS Chlorzoxazone tablets are contraindicated in patients with known intolerance to the drug.

ADVERSE REACTIONS After extensive clinical use of chlorzoxazone-containing products, it is apparent that the product is well tolerated and seldom produces undesirable side effects. Occasional patients may develop gastrointestinal disturbances. It is possible in rare instances that chlorzoxazone may have been associated with gastrointestinal bleeding. Drowsiness, dizziness, lightheadedness, malaise, or overstimulation 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. To report SUSPECTED ADVERSE REACTIONS, contact Camber Pharmaceuticals, Inc. at 1-866-495-1995 or FDA at 1-800-FDA-1088 or http://www.fda.gov/medwatch for voluntary reporting of adverse reactions.

DESCRIPTION Each 375 mg chlorzoxazone tablet contains: Chlorzoxazone USP 375 mg. Each 500 mg chlorzoxazone tablet contains: Chlorzoxazone USP 500 mg. Each 750 mg chlorzoxazone tablet contains: Chlorzoxazone USP 750 mg. Chemical Name: 5-Chloro-2-benzoxazolinone. Structural Formula: Molecular Formula: C 7 H 4 ClNO 2 Molecular Weight: 169.56 Chlorzoxazone, USP is a white or practically white, practically odorless, crystalline powder. Chlorzoxazone USP is slightly soluble in water; sparingly soluble in alcohol, in isopropyl alcohol, and in methanol; soluble in solutions of alkali hydroxides and ammonia. Inactive ingredients: 375 mg contains colloidal silicon dioxide, corn starch, croscarmellose sodium, docusate sodium with sodium benzoate, lactose monohydrate, magnesium stearate and microcrystalline cellulose. 500 mg contains D&C Red 27/Phloxine Aluminium lake, FD&C Yellow 6/Sunset Yellow FCF Aluminium lake, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polysorbate 80, pregelatinized starch, sodium starch glycolate. 750 mg contains colloidal silicon dioxide, corn starch, croscarmellose sodium, docusate sodium with sodium benzoate, lactose monohydrate, magnesium stearate and microcrystalline cellulose. Meets USP dissolution test 5 for 500 mg. FDA approved dissolution method differs from that of the USP for 375 mg and 750 mg. str

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 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.

HOW SUPPLIED Chlorzoxazone tablets, USP are supplied as follows: 375 mg White to off white capsule shaped tablet, debossed ‘126’ on one side and plain on other side. Bottle of 100 tablets with child-resistant closure, NDC 16571-725-01 Bottle of 500 tablets with continuous thread (CT) closure, NDC 16571-725-50 500 mg White to off white capsule shaped tablet, debossed with a break line between “1 and 2” on one side and plain on other side. Bottle of 100 tablets with child-resistant closure, NDC 16571-726-01 Bottle of 500 tablets with continuous thread (CT) closure, NDC 16571-726-50 750 mg White to off white capsule shaped tablet, debossed ‘124’ on the trisected side and plain on the bisected side. Bottle of 100 tablets with child-resistant closure, NDC 16571-727-01 Bottle of 500 tablets with continuous thread (CT) closure, NDC 16571-727-50. Dispense in tight container as defined in the official compendium. Store at 20° to 25° C (68° to 77° F) [see USP Controlled Room Temperature]. Manufactured by: Graviti Pharmaceuticals Pvt. Ltd. Telangana-502307, INDIA. Mfg. Lic. No.: 12/SRD/TS/2017/F/G Manufactured for: Rising Pharma Holdings, Inc. East Brunswick, NJ 08816 Revised: 11/2022 PIR72750-03