Adult Dosing

Musculoskeletal pain & spasm

• 250-500 mg PO tid-qid; increase to 750 mg tid-qid if needed
• Max 750 mg/dose

Pediatric Dosing

Musculoskeletal pain & spasm

• 20 mg/kg or 600 mg/m²/day PO divided tid-qid (FDA unapproved)

• Adjunct to rest, physical therapy, and other measures for the relief of discomfort associated with acute, painful musculoskeletal conditions

• Hypersensitivity to any of the ingredient of the product
• Intolerance to the drug

• N/A

Renal Dose Adjustment

• Renal impairment: Dose adjustments not defined

Hepatic Dose Adjustment

• Hepatic impairment: Use with caution; dose adjustments not defined

See Supplemental Patient Information

• Rare occasions of serious, including fatal, hepatocellular toxicity have occurred; monitor LFTs during treatment; discontinue therapy on occurrence of liver dysfunction symptoms or abnormal liver enzymes
• Avoid concomitant use of alcohol or other central nervous system depressants
• Discontinue therapy on occurrence of hypersensitivity reactions such as urticaria, redness, or itching of the skin

Cautions: Use cautiously in:

• Renal impairment
• Hepatic impairment
• CNS depression
• History of allergic reactions
• Geriatric patients

Supplemental Patient Information

• Instruct patients receiving chlorzoxazone 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; instruct patients to immediately discontinue therapy and consult physician on development of these signs or symptoms

Pregnancy Category:C

Breastfeeding: Safety Unknown. Safety of chlorzoxazone has not been established with respect to the possible adverse effects upon fetal development. Manufacturer advises to use in women of childbearing potential only in the judgment of the physician, the potential benefits outweigh the possible risks.

• CNS: Drowsiness, dizziness, lightheadedness, paradoxical CNS stimulation, malaise, headache
• GI: Hepatotoxicity, GI upset, GI bleeding
• DERM: Rashes, petechiae, ecchymoses
• MISC: Anaphylaxis, angioneurotic edema

• Centrally-acting skeletal muscle relaxant; acts primarily at the level of the spinal cord and subcortical areas of the brain, inhibits multi-synaptic reflex arcs involved in producing and maintaining skeletal muscle spasm of varied etiology resulting in reduction of the skeletal muscle spasm with relief of pain and increased mobility of the involved muscles
• Well absorbed following oral administration
• metabolized in liver; CYP450: Unknown
• Renally excreted (< 1% unchanged)
• Half life: 1.1 hrs

US Trade Name(s)

• Parafon Forte DSC
• Lorzone

US Availability

chlorzoxazone (generic)

• TABS: 250, 375, 500, 750 mg

Parafon Forte DSC

• TABS: 500 mg

Lorzone

• TABS: 375, 750 mg

Canadian Trade Name(s)

• N/A

Canadian Availability

• N/A

UK Trade Name(s)

• N/A

UK Availability

• N/A

Australian Trade Name(s)

• N/A

Australian Availability

• N/A

Analgesics

Skeletal Muscle Relaxants

Pricing data from www.DrugStore.com in U.S.A.

• Parafon Forte DSC 500 MG TABS [Bottle] (MCNEIL)
  30 mg = $92.99
  90 mg = $244.97
• Chlorzoxazone 500 MG TABS [Bottle] (WATSON LABS)
  90 mg = $17.99
  180 mg = $24.98

Warning: This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit drugstore.com.

• Chlorzoxazone 250 MG Oral Tablet (Actavis Totowa, LLC)
• Chlorzoxazone 500 MG Oral Tablet (Actavis Totowa, LLC)
• Chlorzoxazone 500 MG Oral Tablet (Keltman Pharmaceuticals Inc.)
• Chlorzoxazone 500 MG Oral Tablet (TEVA PHARMACEUTICALS USA)
• Parafon Forte DSC 500 MG Oral Tablet (ORTHO-McNEIL PHARMACEUTICAL, INC.)