Assessing drowsiness and cognition after taking Metaxalone

A Prospective, Randomized, Single-blind, Pilot Study to Assess Drowsiness, Cognition, and Fall Risk Following Oral Metaxalone 640 mg (M640) Versus Metaxalone 800 mg in Healthy Subjects"

PHASE4 · Primus Pharmaceuticals · NCT06348303

This study tests how different doses of Metaxalone affect drowsiness and thinking skills in healthy people after they eat a high-fat meal.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment20 (estimated)
Ages18 Years to 55 Years
SexAll
SponsorPrimus Pharmaceuticals (industry)
Locations1 site (Columbus, Ohio)
Trial IDNCT06348303 on ClinicalTrials.gov

What this trial studies

This study evaluates the effects of two different doses of Metaxalone on drowsiness, cognition, and fall risk in healthy participants. Each participant will take a single dose of Metaxalone after a high-fat meal, with assessments conducted before and after the dose. The study involves two dosing sessions spaced one week apart, during which participants will undergo written tests and walking assessments to measure their cognitive function and risk of falls. The total duration of participation is approximately 2-4 weeks.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy adults weighing at least 120 pounds with no significant medical co-morbidities.

Not a fit: Patients currently using medications that affect the sleep-wake cycle or those with known sleep disorders will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into the safety and cognitive effects of Metaxalone, helping to inform its use in clinical settings.

How similar studies have performed: While similar studies on muscle relaxants have been conducted, this specific assessment of Metaxalone's effects on cognition and fall risk is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Weigh at least 120 pounds at Screening
* Medically healthy with no clinically significant medical co-morbidities impact endpoints

Exclusion Criteria:

* Current use of any medications known to affect sleep-wake cycle.
* Known sleep disorder.
* Current use of cimetidine.
* Current use of a monoamine oxidase Inhibitor (MAOI), selective serotonin reuptake inhibitor (SSRI), selective norepinephrine reuptake inhibitor (SNRI), 5- hydroxytryptamine (5-HT) agonist or any drug that has the potential to affect the serotonergic neurotransmitter system (e.g. mirtazapine, trazodone, tramadol).
* Positive urine test for amphetamines, barbiturates, cocaine, opiates, benzodiazepines, or cannabinoids.
* Participants taking skeletal muscle relaxants or sedative hypnotics.
* Participants with gastrointestinal disease affecting absorption.
* Participants with severe hepatic or renal impairment.

Where this trial is running

Columbus, Ohio

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.

View on ClinicalTrials.gov →

Conditions: Healthy Participants

Last reviewed 2026-05-15 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.