Assess the Effect of Metaxalone 640 mg (M640) Compared to Tizanidine 8 mg on Truck 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

Every participant will receive active study drug and one (1 )comparator, in two (2) stages, one after the other. Each drug will be taken one (1) time after a high fat meal. Vital signs and discussion of medications, illness or injury are considered safety assessments and will be discussed at every visit. There will be ( four (4) visits.

Study Overview

• Status: Completed
• Conditions: Cognitive Impairment
• Intervention / Treatment: Drug: metaxalone m640; Drug: tizanidine

Detailed Description

Every participant will receive active study drug and one (1) comparator in two (2) stages, one after the other. Each drug will be taken one (1) time after a high fat meal. Vital signs and discussion of medications, illness or injury are considered safety assessments and will be discussed at every visit.

The Screening Visit will be followed by the Baseline (Visit 1) 1-14 days later. At the Baseline Visit participants will be given written tests to measure thinking process. You will also be asked to take a computer driving simulation test.

Visits 2 and 3 approximately one (1) week apart will be the dosing days after eating a high fat meal within 30 minutes. The testing from the Baseline Visit will be repeated at four (4) hours and 1.5 hours after dosing with comparator drug.

The End of Study safety visit will take place two (2) weeks later. Participants will be given discharge instructions.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Arizona
    • Peoria, Arizona, United States, 85381
      • Sun Valley Arthritis Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: metaxalone m640 mg; metaxalone micronized 640 mg tablet, single dose at Visit 2 or Visit 3	Drug: metaxalone m640; A single dose of micronize metaxalone 640 mg; Other Names: Metaxalone 640
Active Comparator: tizanidine 8 mg; tizanidine 8 mg tablet, single dose at Visit 2 or Visit 3	Drug: tizanidine; A single dose of tizanidine 8 mg; Other Names: Zanaflex

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline, Standard Deviation of Lateral Position	Using the One Motion GT Elite Mini- Simulator (SimGear) with Carnet Soft Driving Simulation Software	Baseline, Visit 2 dosing, (day 1), Visit 3 dosing, (day 8)
Change from baseline of participants' reasoning ability to recognize differences in six (6) computer generated shapes for 30 minutes	Creyos Cognitive Test	Visit 2 (Day 0), Visit 3 (Day 1). Visit 4 (Day 8)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline of participants' subjective report of drowsiness on a 10-point scale	Karolinska Sleepiness Scale where 1 = extremely alert and 10 = extremely sleepy, can't keep awake	Visit 2 (Day 0), Visit 3 (Day 1). Visit 4 (Day 8)
Percentage of participants unable to maintain Tandem Stand Position for more than 10 seconds (position 3 of the 4-Stage Balance Test)	Validated 4-Stage Balance Test after completion of an FDA standardized high-fat meal. Place one foot in front of the other, heel touching toes.	Visit 2 (Day 0), Visit 3 (Day 1). Visit 4 (Day 8)
The number of product related adverse events experienced by participants from Visit 1 through Visit 4	Adverse and Serious Adverse Events	Baseline, Visit 2 (Day 0), Visit 3 (Day 1), Visit 4 (Day 8), Visit 4 (Day 15)

Collaborators and Investigators

• Sponsor: Primus Pharmaceuticals
• Collaborators: Sun Valley Arthritis Center
• Investigators: Study Director: J C Lukban, DO, Sponsor GmbH

Study record dates

Study Major Dates

• Study Start (Actual): April 29, 2024
• Primary Completion (Actual): December 30, 2024
• Study Completion (Actual): March 6, 2025

Study Registration Dates

• First Submitted: April 20, 2024
• First Submitted That Met QC Criteria: April 20, 2024
• First Posted (Actual): April 24, 2024

Study Record Updates

• Last Update Posted (Actual): August 22, 2025
• Last Update Submitted That Met QC Criteria: August 20, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Impaired driving
• Additional Relevant MeSH Terms: Mental Disorders; Neurocognitive Disorders; Cognition Disorders; Cognitive Dysfunction; Anti-Infective Agents; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Enzyme Inhibitors; Sensory System Agents; Analgesics; Neurotransmitter Agents; Adrenergic alpha-2 Receptor Agonists; Adrenergic alpha-Agonists; Adrenergic Agonists; Adrenergic Agents; Protein Synthesis Inhibitors; Anticonvulsants; Neuromuscular Agents; Parasympatholytics; Muscle Relaxants, Central; Tizanidine; Oxazolidinones; Metaxalone
• Other Study ID Numbers: PMDAC-01

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No