Klorzoxazon Orifarm (Chlorzoxazone)

Chlorzoxazone works on the central nervous system to reduce muscle tone and alleviate spasm-related discomfort.

• Muscle spasm: decreases involuntary muscle contraction and associated pain.
• Acute low back pain: provides short‑term relief of pain and stiffness in the lumbar region.
• Musculoskeletal pain: eases discomfort from strains, sprains and overuse injuries.
• Muscle strains: helps restore normal muscle function after minor injuries.

• Chlorzoxazone acts as a non‑opioid centrally acting muscle relaxant. It modulates neuronal activity in the spinal cord and subcortical areas, likely by inhibiting interneuronal pathways that maintain muscle tone, thereby reducing the frequency and intensity of muscle spasms without directly affecting the skeletal muscle itself.

Adverse reactions may occur with chlorzoxazone therapy.

Common Side Effects

• Drowsiness: mild to moderate sedation reported in many patients.
• Dizziness: sensation of light‑headedness, especially when standing quickly.
• Nausea: occasional upset stomach or feeling of queasiness.
• Headache: transient cranial discomfort.
• Fatigue: generalized tiredness during treatment.
• Gastrointestinal upset: mild abdominal discomfort or dyspepsia.

Serious or Rare Side Effects

• Hepatotoxicity: signs of liver injury such as jaundice or elevated enzymes.
• Severe skin reactions: rash, Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Blood dyscrasias: agranulocytosis, leukopenia or thrombocytopenia.
• Anaphylaxis: acute allergic reaction with respiratory distress.
• Hepatic failure: rare but potentially life‑threatening liver dysfunction.

Before initiating chlorzoxazone, consider the following safety measures.

• Assess liver function: avoid use in patients with known hepatic impairment.
• Avoid alcohol: concurrent intake may enhance sedation and dizziness.
• Use caution in the elderly: increased sensitivity to central nervous system effects.
• Monitor for excessive sedation: advise patients not to operate machinery while impaired.
• Do not combine with other CNS depressants without medical supervision.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Chlorzoxazone may interact with other medicines, altering its safety or effectiveness.

Major Interactions (Avoid)

• CNS depressants (e.g., opioids, benzodiazepines, alcohol): additive sedation and respiratory depression.
• Strong hepatic enzyme inhibitors (e.g., erythromycin, fluconazole): increased chlorzoxazone plasma concentrations.

Moderate Interactions (Monitor Closely)

• Antihistamines: may heighten drowsiness.
• Selective serotonin reuptake inhibitors (SSRIs): possible increase in central sedation.
• Antihypertensive agents: potential enhancement of hypotensive effects.