Last reviewed 2026-04-20 · How we verify

Parafon Forte Dsc (CHLORZOXAZONE)

Parafon Forte DSC (CHLORZOXAZONE) is a muscle relaxant medication originally developed by Janssen R and D and currently owned by Ortho McNeil Pharm. It targets nitric oxide synthase in endothelial cells to provide relief from muscle spasm and pain. This medication has been FDA-approved since 1958 for treating muscle spasm with pain and spasticity. Parafon Forte DSC is available as a generic medication, with 21 generic manufacturers, and is off-patent. As a result, it is widely available and affordable.

At a glance

Approved indications

• Muscle Spasm with Pain
• Spasticity

Common side effects

• Gastrointestinal bleeding
• Drowsiness
• Dizziness
• Lightheadedness
• Malaise
• Over-stimulation
• Allergic type skin rashes
• Petechiae
• Ecchymoses
• Angioneurotic edema
• Anaphylactic reactions
• Discoloration of the urine

Drug interactions

• disulfiram
• sodium oxybate

Key clinical trials

• Effectiveness of Chlorzoxazone Versus Orphenadrine Citrate in Alleviating Bruxism Pain (PHASE4)
• Pharmacokinetic and Bioequivalence Comparison of Baclofen and Chlorzoxazone Administered Individually or Concurrently (PHASE1)
• Placebo-Controlled Cross Over Trial of Chlorzoxazone Intake (PHASE4)
• Effect of Ethanol and Genetic Polymorphisms on Bupropion Metabolism (NA)
• Chlorzoxazone in Hip and Knee Arthroplasty (PHASE4)
• Evaluation of CYP450 Activities in Diabetic Patients vs. Non-diabetic Subjects (PHASE4)
• Effects of LRYGB on Pharmacokinetics of Nine CYP Probe Drugs (NA)
• A Study to Investigate the Potential Influence of Nitisinone on the Metabolism and the Transport of Other Drugs in Healthy Volunteers (PHASE1)

Primary sources

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