Metaxalone for Lower Back Pain

Recruiting at 20 trial locations

Overseen By S Sodhi

Age: 18+

Sex: Any

Trial Phase: Phase 4

Sponsor: Primus Pharmaceuticals

Must not be taking: Skeletal relaxants, Pain relievers, Cimetidine, MAO inhibitors

Disqualifiers: Clinically significant conditions, others

Prior Safety Data This treatment has passed at least one previous human trial

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 2

Duration: 1 week

50 Participants Needed

Trial Summary

What is the purpose of this trial?

The goal of this clinical trial is to learn if a modification to metaxalone 640 mg can reduce low back and leg pain. The participants will be 18 to 80 years old, healthy with newly occurring back or leg pain. The main question aims to compare a group taking active treatment and a group taking a look-alike substance containing no active treatment. All participants will answer questions on Day 1, before treatment, and on 7-day after treatment, about: * Amount and quality of pain * Interference with physical activity * Interference with sleep

Will I have to stop taking my current medications?

Yes, you will need to stop taking any current skeletal relaxants, pain relievers, cimetidine, or monoamine oxidase inhibitors to participate in this trial.

What data supports the effectiveness of the drug Metaxalone for lower back pain?

Research shows that Metaxalone can reduce inflammation, which is often linked to pain, by suppressing certain chemicals in the body that cause inflammation. This suggests it might help with painful conditions like lower back pain. ^{1 2 3 4 5}

How does the drug Metaxalone differ from other treatments for lower back pain?

Metaxalone is unique because it acts as a skeletal muscle relaxant and may suppress the production of inflammatory cytokines (proteins that signal inflammation) associated with pain, which is not a common mechanism among other lower back pain treatments. ^{1 2 3 4 6}

Research Team

S Sodhi

Principal Investigator

Illumination Health

Eligibility Criteria

This trial is for adults aged 18-80 with new low back or leg pain, who can respond to surveys. They must have a pain score of at least 6 and no other conditions affecting their pain. People using muscle relaxants, other pain meds, cimetidine, or MAO inhibitors cannot join.

Inclusion Criteria

Baseline Numeric Pain Scale ≥ 6

I don't have conditions that worsen my pain significantly.

I can respond to surveys via text or email.

Exclusion Criteria

I am currently using pain relievers.

I am currently taking cimetidine or monoamine oxidase inhibitors.

I am currently taking medication for muscle relaxation.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive metaxalone 640 mg or placebo every 6 hours for 7 days

1 week

1 visit (in-person) on Day 1

Follow-up

Participants are monitored for safety and effectiveness after treatment

1 week

1 visit (in-person) on Day 7

Treatment Details

Interventions

• Metaxalone

Trial Overview The study tests if modified metaxalone (a muscle relaxant) helps reduce acute lower back and leg pain compared to a placebo. Participants will be randomly assigned to receive either the drug or placebo and will report on their pain and its impact over a week.

Participant Groups

Group I: Active M640 Active Control 1 Intervention

Metaxalone micronized 640 mg over encapsulated tablet Taken orally every 6 hours for 7 days

Group II: Placebo Placebo Group 1 Intervention

Inactive placebo capsule 640 mg Taken orally every 6 hours for 7 days

Metaxalone is already approved in United States for the following indications:

Approved in United States as Metaxalone for:

• Acute, painful musculoskeletal conditions

Who Is Running the Clinical Trial?

Primus Pharmaceuticals

Lead Sponsor

Trials

22

Recruited

2,400+

Illumination Health

Collaborator

Trials

3

Recruited

1,300+

Findings from Research

In a study of 142 adults who ingested metaxalone, higher doses (over 2400 mg) were linked to more serious medical outcomes, with 100% of these cases requiring management at health care facilities.

The most common adverse effects included drowsiness, tachycardia, and agitation, with 50.8% of cases resulting in 'no effect', indicating that while some ingestions can be serious, many do not lead to severe outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Adult metaxalone ingestions reported to Texas poison control centers, 2000-2006. Forrester, MB.[2013]

Metaxalone demonstrated an ability to inhibit the proliferation and promote the death of inflammatory macrophages in vitro, suggesting a potential mechanism for its effects on muscle pain.

The study found that metaxalone reduced the production of inflammatory cytokines and decreased levels of key inflammatory markers, indicating its role in suppressing inflammation at the cellular level.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Metaxalone Suppresses Production of Inflammatory Cytokines Associated with Painful Conditions in Mouse Macrophages RAW264.7 Cells in Vitro: Synergistic Effect with β-caryophyllene. Yamaguchi, M., Levy, RM.[2021]

A case study indicates that metaxalone, a muscle relaxant, was the sole cause of death in a relatively young individual, highlighting its potential risks despite being rarely associated with fatalities.

Blood concentration levels of metaxalone were significantly high at the time of hospital admission (37.4 mcg/mL) and postmortem, suggesting that even at these levels, the drug's safety profile may need further evaluation, especially considering the blood-to-plasma ratio of 1.4.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A rare fatality attributed solely to metaxalone. Curtis, B., Jenkins, C., Wiens, AL.[2015]

A new high-throughput tandem mass spectroscopic method was developed to accurately measure metaxalone levels in human plasma, ensuring precise and reliable results for clinical studies.

The method demonstrated excellent stability and recovery rates, with no interference from other substances, making it suitable for evaluating metaxalone's effectiveness in pain relief across various plasma conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Metaxalone estimation in biological matrix using high-throughput LC-MS/MS bioanalytical method. Goswami, D., Saha, A., Gurule, S., et al.[2013]

A new reversed phase ultra performance liquid chromatography (RP-UPLC) method was developed to accurately measure metaxalone in pharmaceutical products, effectively separating it from known and unknown impurities within 6 minutes.

Metaxalone showed significant degradation under basic stress conditions but remained stable under acid, hydrolytic, thermal, and photolytic conditions, demonstrating the method's ability to indicate the drug's stability.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Development of a Stability-Indicating RP-UPLC Method for Rapid Determination of Metaxalone and its Degradation Products in Solid Oral Dosage Form. Trivedi, RK., Patel, MC.[2021]

A fatal overdose case involving metaxalone revealed high concentrations of the drug (19 mg/L in aortic blood) alongside other substances, indicating potential risks associated with its use, especially in combination with other medications.

The study highlights the limited information on metaxalone toxicity, as the pathologist attributed the cause of death primarily to hydrocodone intoxication, suggesting that while metaxalone can be present in overdose cases, its direct role in fatalities may require further investigation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Metaxalone (Skelaxin)-related death. Poklis, JL., Ropero-Miller, JD., Garside, D., et al.[2019]

References

1. England pubmed.ncbi.nlm.nih.gov

Adult metaxalone ingestions reported to Texas poison control centers, 2000-2006. [2013]

2. Netherlands pubmed.ncbi.nlm.nih.gov

Metaxalone Suppresses Production of Inflammatory Cytokines Associated with Painful Conditions in Mouse Macrophages RAW264.7 Cells in Vitro: Synergistic Effect with β-caryophyllene. [2021]

3. England pubmed.ncbi.nlm.nih.gov

A rare fatality attributed solely to metaxalone. [2015]

4. Netherlands pubmed.ncbi.nlm.nih.gov

Metaxalone estimation in biological matrix using high-throughput LC-MS/MS bioanalytical method. [2013]

5. Switzerland pubmed.ncbi.nlm.nih.gov

Development of a Stability-Indicating RP-UPLC Method for Rapid Determination of Metaxalone and its Degradation Products in Solid Oral Dosage Form. [2021]

6. England pubmed.ncbi.nlm.nih.gov

Metaxalone (Skelaxin)-related death. [2019]