Metaxalone Stats - Substance Search

Pharmacology

DrugBank

Half-life 9.2 (+/- 4.8) hours State Solid Vd * 800 L Metabolism Probably hepatic.

Description

Metaxalone is a moderate to strong muscle relaxant used in the symptomatic treatment of musculoskeletal pain caused by strains, sprains, and other musculoskeletal conditions. It is marketed by King Pharmaceuticals under the brand name Skelaxin®. Its main mechanism of action is thought to involve general central nervous system depression. Metaxalone is associated with few side effects and is available as a 800 mg scored tablet.

Mechanism of Action

The mechanism of action of metaxalone in humans has not been established, but may be due to general central nervous system depression.

Pharmacodynamics

Metaxalone is a skeletal muscle relaxant indicated as an adjunct to rest, physical therapy, and other measures for the relief of discomforts associated with acute, painful musculoskeletal conditions. The mode of action of this drug has not been clearly identified, but may be related to its sedative properties. Metaxalone does not directly relax tense skeletal muscles in man.

Absorption

The absolute bioavailability of metaxalone from Skelaxin tablets is not known.

Toxicity

LD₅₀=775mg/kg (Rat, oral); LD₅₀=1690 mg/kg (Mouse, oral). When determining the LD₅₀ in rats and mice, progressive sedation, hypnosis and finally respiratoryfailure were noted as the dosage increased. In dogs, no LD₅₀ could be determined as the higher doses produced an emetic action in 15 to 30 minutes. Some adverse events associated with the drug include nausea, vomiting, drowsiness and CNS side effects such as dizziness, headache, and irritability.

Indication

For the treatment of painful peripheral musculoskeletal conditions and spasticity from upper motor neuron syndromes.

Elimination

Metaxalone is metabolized by the liver and excreted in the urine as unidentified metabolites.

Clearance

* 68 +/- 50 L/h Subjects received 1×400mg tablet under fasted conditions * 66 +/- 51 L/h Subjects received 2×400 mg tablets under fasted conditions

Tolerance & Pharmacokinetics

drugs.wiki

Tolerance Decay

Full tolerance 3d Half tolerance 8d Baseline ~14d

Experience Report Analysis

Erowid

21 Reports

2002–2020 Date Range

9 With Age Data

15 Effects Detected

Demographics

Gender Distribution

Age Distribution

Reports Over Time

Effect Analysis

Erowid

Effects aggregated from 21 experience reports (21 Erowid)

21 Reports

15 Effects Detected

8 Positive

4 Adverse

3 Neutral

Effect Sentiment Distribution

Confidence Distribution

Positive Effects 8

Anxiety Suppression 42.9% 70%

Sedation 38.1% 70%

Stimulation 19.0% 70%

Focus Enhancement 19.0% 70%

Euphoria 19.0% 70%

Pain Relief 14.3% 70%

Empathy 14.3% 70%

Music Enhancement 14.3% 70%

Adverse Effects 4

Nausea 28.6% 70%

Increased Heart Rate 23.8% 70%

Sweating 14.3% 70%

Confusion 14.3% 70%

Dosage Distribution

Dose distribution from experience reports

Median: 800.0 mg IQR: 800.0–2500.0 mg n=10

Real-World Dose Distribution

62K Doses

From 37 individual dose entries

Oral (n=31)

Median: 800.0mg 25th: 800.0mg 75th: 1600.0mg 90th: 3200.0mg

mg/kg median: 11.593 mg/kg 75th: 22.107

Form / Preparation

Most common forms and preparations reported

Body-Weight Dosing

Dose relative to body weight from reports with weight data

Median: 14.109 mg/kg IQR: 9.281–36.072 mg/kg n=10

Redose Patterns

Redosing behavior across 15 reports

26.7% Redosed

1.6 Avg Doses

30m Median Interval

Metaxalone Stats & Data