Chlorzoxazone

Generic name: Chlorzoxazone

Drug class: Skeletal muscle relaxants

Dosage form: Oral tablets (250 mg, 375 mg, 500 mg, 750 mg)

Root of administration: Oral

Dose:

• Initial dose: 250 to 500 mg orally, 3 to 4 times daily
• If inadequate response: Increase to 750 mg orally, 3 to 4 times daily
• Maintenance: Reduce dose as improvement occurs

Mechanism of action: Chlorzoxazone is a centrally acting muscle relaxant that inhibits multisynaptic reflex arcs at the spinal cord and subcortical brain levels, leading to reduced muscle spasms and associated pain.

Drug usage cases:

• Relief of discomfort associated with acute, painful musculoskeletal conditions
• Adjunct to rest and physical therapy for muscle strains and sprains

Drug contraindications:

• Known hypersensitivity to chlorzoxazone

Side effects:

• Drowsiness
• Dizziness
• Lightheadedness
• Malaise
• Overstimulation
• Gastrointestinal disturbances
• Skin rashes
• Petechiae
• Ecchymoses
• Rare cases of hepatocellular toxicity

Warnings:

• Monitor for signs of liver dysfunction, including fever, rash, anorexia, nausea, vomiting, fatigue, right upper quadrant pain, dark urine, or jaundice; discontinue use if these occur
• Concomitant use with alcohol or other central nervous system depressants may have an additive effect
• Use with caution in patients with known allergies or a history of allergic reactions to drugs; discontinue if sensitivity reactions occur

Use during pregnancy or breastfeeding: The safe use of chlorzoxazone during pregnancy has not been established. It should be used in pregnant women only when the potential benefits outweigh the possible risks. The effects of chlorzoxazone during breastfeeding are not well studied; exercise caution and consult a healthcare provider before use.