Comparing Metaxalone and Tizanidine on Driving Ability and Cognition

Assessment of the Effect of Metaxalone 640 mg (M640) on Truck Driving Ability and Cognition Compared to Tizanidine 8 mg: A Prospective, Single-blind, Within-subject Pilot Study

Phase 4 Interventional Primus Pharmaceuticals · NCT06382662

This study tests whether Metaxalone or Tizanidine affects thinking skills and driving ability in people by having them try both medications after a meal.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment20 (estimated)
Ages20 Years to 70 Years
SexAll
SponsorPrimus Pharmaceuticals Industry-sponsored
Locations1 site (Peoria, Arizona)
Trial IDNCT06382662 on ClinicalTrials.gov

What this trial studies

This study evaluates the effects of Metaxalone 640 mg compared to Tizanidine 8 mg on cognitive function and driving ability. Participants will take each medication after a high-fat meal in a crossover design, allowing for direct comparison. The study includes multiple visits for safety assessments, cognitive testing, and driving simulations. Vital signs and discussions regarding health will be monitored throughout the trial.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 20 and older who weigh at least 120 pounds and can consume a high-fat meal.

Not a fit: Patients currently taking medications that affect the sleep-wake cycle or those with certain medical conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could help identify safer medication options for individuals with cognitive impairment who need to drive.

How similar studies have performed: Other studies have explored the effects of medications on cognitive function and driving, but this specific comparison is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* equal to or greater than 20 years old
* weight at least 120 pounds
* medically healthy
* able to eat a high fat meal

Exclusion Criteria:

* medications known to affect sleep-wake cycle
* current use of cimetidine
* current use of certain anti-depressants
* current us of certain antibiotics
* positive urine drug test for mind altering medications

Where this trial is running

Peoria, Arizona

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Cognitive ImpairmentImpaired driving
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.