Brands, Medical Use, Clinical Data
Drug Category
- Muscle Relaxants, Central
Dosage Forms
Brands / Synonyms
Biomioran; Chloroxazone; Chlorzoxane; Chlorzoxazon; Chlorzoxazone; Escoflex; EZE-DS; Flexazone; Mioran; Miotran; Myoflexin; Myoflexine; Neoflex; Paraflex; Parafon Forte Dsc; Pathorysin; Relaxazone; Remular; Remular-S; Solaxin; Strifon Forte Dsc; Usaf Ma-10
Indications
For the relief of discomfort associated with acute painful musculoskeletal conditions.
Pharmacology
Chlorzoxazone, a synthetic compound, inhibits antigen-induced bronchospasms and, hence, is used to treat asthma and allergic rhinitis. Chlorzoxazone is used as an ophthalmic solution to treat conjunctivitis and is taken orally to treat systemic mastocytosis and ulcerative colitis. Chlorzoxazone is also 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 a.c. 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.
Mechanism of Action
Chlorzoxazone inhibits degranulation of mast cells, subsequently preventing the release of histamine and slow-reacting substance of anaphylaxis (SRS-A), mediators of type I allergic reactions. Chlorzoxazone also may reduce the release of inflammatory leukotrienes. Chlorzoxazone may act by inhibiting calcium influx.
Absorption
Not Available
Toxicity
Oral, mouse: LD50 = 440 mg/kg; Oral, rat: LD50 = 763 mg/kg; Symptoms of overdose include diarrhea, dizziness, drowsiness, headache, light-headedness, nausea, and vomiting.
Biotrnasformation / Drug Metabolism
Chlorzoxazone is rapidly metabolized in the liver and is excreted in the urine, primarily in a conjugated form as the glucuronide.
Contraindications
PARAFON FORTE DSC chlorzoxazone is contraindicated in patients with known intolerance to the drug.
Drug Interactions
The concomitant use of alcohol or other central nervous system depressants may have an additive effect.
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