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Metaxalone 800 mg Tablet, 60-count — NDC 63187-0490-60 package photo
Label image from the product's FDA listing (DailyMed) — may show a different pack size or an older label revision.

Metaxalone 800 mg Tablet, 60-count — NDC 63187-490-60 (Billing 63187-0490-60)

by Proficient Rx LP · 60 TABLET in 1 BOTTLE

This is a package of 60 tablets of Metaxalone 800 mg Tablet from Proficient Rx LP, marketed since May 2013 and currently FDA-listed.

NDC 63187-0490-60
🏷️ FDA NDC (as labeled) 63187-490-60 billing pads the product segment with a zero
This package
Contains60-count Pack sizes4 compare ↓
Also priced by: Part D plans $1.73/unit — full pricing hub ↓
Product page 63187-0490-10 Also comes in: 10 tablets 63187-490-10 30 tablets 63187-490-30 90 tablets 63187-490-90
Rx only Generic On market Non-controlled ⇄ Compare with another NDC
🗂️ FDA directory synced Oct 8, 2026 · this listing last changed Oct 8, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

This page is curated, coded, and maintained by

Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

NDC database record

One package, one record: these facts belong to NDC 63187-490-60 alone.

Record
FDA NDC Directory package listing · Human prescription drug
Code segments
63187 labeler · 490 product · 60 package
Package marketed since
Feb 2, 2015
Sample package
No — commercial package
Listing certified through
Dec 31, 2027
Billing quantity
60 EA per package
Barcode (UPC)
0363187490300
FDA record last changed
Oct 8, 2026

Identity & classification

Regulatory identifiers FDA, NLM and CMS codes for this package

FDA NDC (as labeled) 63187-490-60
Product NDC 63187-490
11-digit billing NDC 63187049060
NCPDP billing unit EA — each (per item)
RxCUI 351254
UNII 1NMA9J598Y
UPC 0363187490300
Application # ANDA203399
SPL Set ID fba1601d-3ac4-41cf-9548-35ec4994a95e
Established class (EPC) Muscle Relaxant
Physiologic effect Centrally-mediated Muscle Relaxation
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2013-05-31
Route ORAL
Dosage form TABLET
Substance METAXALONE
TE code (Orange Book) AB · RLD · RS

Drug-database identifiers Medi-Span GPI and First Databank GCN / HICL / AHFS classification

GPI-14 75100060000320
GPI class Metaxalone
GCN Seq No 051112
GCN 91765
HICL code 001945
Ingredient (HICL) Metaxalone
HIC1 code H
Therapeutic class — broad (HIC1) Nervous System (Except Autonomic)
HIC2 code H6
Therapeutic class — intermediate (HIC2) Drugs Acting Principally On The Midbrain
HIC3 code H6H
Therapeutic class — specific (HIC3) Skeletal Muscle Relaxants
AHFS code 12:20.04.00
AHFS class Centrally Acting Skeletal Muscle Relaxnt
FDB label name METAXALONE 800 MG TABLET
FDB brand name Metaxalone
Legend status F — Federal legend — prescription drug or device
Quick answers
  • GSN (GCN sequence number): 051112
  • GCN: 91765
  • GPI-14 (Medi-Span): 75100060000320
  • HICL (First Databank): 001945
  • AHFS class code: 12:20.04.00
  • RxCUI (RxNorm): 351254
Why two NDCs? The FDA registers this code as 63187-490-60 — a 5-3-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the product segment → 63187-0490-60. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

RxNorm drug class

This medicine belongs to the Muscle Relaxant class.

Pharmacologic class Muscle Relaxant
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

Clinical

Label name METAXALONE 800 MG TABLET Ingredient Metaxalone
📗 Our plain-language guide HelloPharmacist
  • It helps relieve discomfort from sudden, painful muscle and bone conditions. It is meant to be used along with rest and physical therapy, not by itself. It is for adults and teens...
  • Take it by mouth, with or without food, usually three to four times a day as your prescriber directs. Don't take more than prescribed. If you were on Skelaxin 800 mg, don't switch...
  • The most common are drowsiness, dizziness, headache, feeling nervous or irritable, nausea, vomiting and stomach upset. Be careful driving until you know how it affects you.
  • It's best to avoid it. Alcohol and other sedating medicines can add to the sleepiness and may slow your breathing.
📖 Read our full Metaxalone guide →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer eachPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · Q2 2026 $1.73 $103.84 / 60 tablets
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

Packaging — all sizes for this product

Package NDCDescription Marketing startMarketing endStatus
63187-0490-10 63187-490-10 Main listing 10 TABLET in 1 BOTTLE 2015-02-02 — Active
63187-0490-30 63187-490-30 30 TABLET in 1 BOTTLE 2015-02-02 — Active
63187-0490-60 You're viewing this 60 TABLET in 1 BOTTLE 2015-02-02 — Active
63187-0490-90 63187-490-90 90 TABLET in 1 BOTTLE 2015-02-02 — Active

You're viewing one of 4 pack sizes for this product.

Pack size FAQ

What quantity is in this package?
This is a 60-count package — 60 tablet in 1 bottle.
How does this package differ from NDC 63187-0490-10?
Both are Metaxalone 800 mg Tablet — the drug itself is identical. This page's package is the 60-count one, while NDC 63187-0490-10 is the 10 tablets package.
What NDC number is used to bill for this package of Metaxalone 800 mg Tablet?
Use the 11-digit billing form listed in the identifiers section of this page. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Metaxalone 800 mg 00527-1435-01 Lannett 100 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 00591-2341-01 Actavis 100 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 00904-6831-04 Major 30 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 50228-0323-01 ScieGen 100 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 50268-0530-15 AvPAK 50 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 55111-0650-01 Dr. 100 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 60687-0663-21 American 30 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 65162-0553-10 Amneal 100 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 68001-0485-00 BluePoint 100 tablets $0.452 AB Availability likely —
Metaxalone 800 mg 42291-0985-50 AvKARE 500 tablets — AB FDA listed —
Metaxalone 800 mg 50090-3650-00 A-S 30 tablets — AB FDA listed —
Metaxalone 800 mg 50090-3670-00 A-S 20 tablets — AB FDA listed —
Metaxalone 800 mg 51655-0171-20 Northwind 20 tablets — AB FDA listed —
Metaxalone 800 mg 51655-0792-20 Northwind 20 tablets — AB FDA listed —
Metaxalone 800 mg 53746-0553-01 Amneal 100 tablets — AB FDA listed —
Metaxalone 800 mg 55700-0494-30 Quality 30 tablets — AB FDA listed —
Metaxalone 800 mg 60760-0093-06 St. 6 tablets — AB Discontinued —
Metaxalone 800 mg 60760-0289-06 St. 6 tablets — AB FDA listed —
Metaxalone 800 mg 61919-0832-90 DIRECT 90 tablets — AB FDA listed —
Metaxalone 800 mgthis 63187-0490-60 Proficient 60 tablets — AB FDA listed —
Metaxalone 800 mg 63629-2097-01 Bryant 100 tablets — AB FDA listed —
Metaxalone 800 mg 63629-8014-01 Bryant 30 tablets — AB FDA listed —
Metaxalone 800 mg 68788-7675-00 Preferred 15 tablets — AB FDA listed —
Metaxalone 800 mg 68788-8678-01 Preferred 100 tablets — AB FDA listed —
Metaxalone 800 mg 69306-0100-01 Doc 100 tablets — AB FDA listed —
Metaxalone 800 mg 69306-0311-20 Doc 20 tablets — AB FDA listed —
Metaxalone 800 mg 70518-0771-00 REMEDYREPACK 90 tablets — AB FDA listed —
Metaxalone 800 mg 70518-4559-00 REMEDYREPACK 90 tablets — AB FDA listed —
Metaxalone 800 mg 71205-0016-10 Proficient 10 tablets — AB FDA listed —
Metaxalone 800 mg 71205-0326-20 Proficient 20 tablets — AB FDA listed —
Metaxalone 800 mg 71205-0426-14 Proficient 14 tablets — AB FDA listed —
Metaxalone 800 mg 71335-0375-00 Bryant 100 tablets — AB FDA listed —
Metaxalone 800 mg 71335-0958-00 Bryant 100 tablets — AB FDA listed —
Metaxalone 800 mg 71335-2066-01 Bryant 30 tablets — AB FDA listed —
Metaxalone 800 mg 72162-1083-01 Bryant 100 tablets — AB FDA listed —
Metaxalone 800 mg 72189-0645-30 Direct_Rx 30 tablets — AB FDA listed —
Metaxalone 800 mg 72789-0028-15 PD-Rx 15 tablets — AB FDA listed —
Metaxalone 800 mg 76420-0232-20 Asclemed 20 tablets — AB FDA listed —
Metaxalone 800 mg 76420-0898-01 Asclemed 100 tablets — AB FDA listed —
Metaxalone 800 mg 80425-0084-02 Advanced 60 tablets — AB FDA listed —
Metaxalone 800 mg 80425-0122-02 Advanced 60 tablets — AB FDA listed —
Metaxalone 800 mg 80425-0131-02 Advanced 60 tablets — AB FDA listed —
Metaxalone 800 mg 80425-0524-01 Advanced 30 tablets — AB FDA listed —
Metaxalone 800 mg 80425-0580-01 Advanced 30 tablets — AB FDA listed —
Metaxalone 800 mg 85509-1435-01 PHOENIX 120 tablets — AB FDA listed —
Metaxalone 800 mg 85509-2341-01 PHOENIX 100 tablets — AB FDA listed —
Metaxalone 800 mg 85766-0011-01 Sportpharm 100 tablets — AB FDA listed —
Metaxalone 800 mg 85766-0143-01 Sportpharm 100 tablets — AB FDA listed —
Metaxalone 800 mg 68788-4168-01 Preferred 100 tablets — AB FDA listed —
Metaxalone 800 mg 72789-0592-30 PD-Rx 30 tablets — AB FDA listed —
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
2013
On the market since
May 2013
📍
2026
Currently FDA-listed
13 years listed
🔓
·
Generic on the market
this product is a generic
✅This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

What it looks like

Color Pink
ShapeCapsule
ImprintAN;553
Size19 mm
ScoringScored — splits in 2
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

🧪 Avoiding an ingredient? See Metaxalone inactive ingredients by manufacturer: every current product's list side by side, so you can ask your pharmacy for the version that does not list it.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • UNII H0G9379FGK
    Calcium carbonate is a white mineral powder used as a filler and buffering agent in medicines. It helps give tablets their bulk and size while neutralizing stomach acid in some formulations.
  • UNII WZB9127XOA
    A synthetic red dye used to color medications and make them easier to identify. It serves as a colorant in tablets, capsules, and liquid formulations.
  • UNII 3NXW29V3WO
    Hypromellose is a plant-based thickener made from cellulose. It's used in medicines as a binder to hold ingredients together, a coating for tablets, and a thickener for liquids.
  • UNII EWQ57Q8I5X
    Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
  • UNII OP1R32D61U
    Microcrystalline cellulose is a purified form of cellulose, a natural fiber from plant sources. It acts as a binder and filler in tablets and capsules, helping hold ingredients together and give the medicine its shape and size.
  • UNII FZ989GH94E
    Povidone is a synthetic polymer made from a plastic-like material. It acts as a binder to hold tablet ingredients together and as a disintegrant to help the tablet break apart in your stomach so the medicine can be absorbed.
  • UNII ETJ7Z6XBU4
    Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
  • UNII 5856J3G2A2
    A starch-based powder made from potatoes and processed with sodium. It acts as a disintegrant, helping the tablet or capsule break apart quickly in the stomach so the medicine can be absorbed.
  • UNII 7CV7WJK4UI
    Sodium stearyl fumarate is a synthetic compound made from stearyl alcohol and fumaric acid. It acts as a lubricant and glidant in tablets and capsules, helping ingredients flow smoothly during manufacturing and preventing sticking.

9 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMed — ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

Manufacturer & labeler

LabelerProficient Rx LP
Application holderAMNEAL PHARMACEUTICALS
FDA applicationANDA203399 (ANDA)
Labeler code63187
First marketedMay 2013
Product typeHuman Prescription Drug
Portfolio1,729 products on file

More NDCs from Proficient Rx LP labeler code 63187

The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Very long sections are excerpted here and marked; the full text is on DailyMed (linked in the sources below). Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage ⏱️ Dosage and Administration ⛔ Contraindications ⚠️ Warnings 🤒 Adverse Reactions 🔄 Drug Interactions 🤰 Pregnancy 🧒 Pediatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 🧬 Mechanism of Action 📦 How Supplied / Storage and Handling 📋 Description 💬 Information for Patients ⚠️ Precautions 🍼 Nursing Mothers 🧬 Pharmacokinetics 📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 📄 Package Label / Principal Display Panel
🎯 Indications and Usage 57 words ▾

INDICATIONS AND USAGE Metaxalone is 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.

⏱️ Dosage and Administration 26 words ▾

DOSAGE AND ADMINISTRATION The recommended dose for adults and children over 12 years of age is one 800 mg tablet three to four times a day.

⛔ Contraindications 24 words ▾

CONTRAINDICATIONS Known hypersensitivity to any components of this product. Known tendency to drug induced, hemolytic, or other anemias. Significantly impaired renal or hepatic function.

⚠️ Warnings 12 words ▾

WARNINGS Metaxalone may enhance the effects of alcohol and other CNS depressants.

🤒 Adverse Reactions 50 words ▾

ADVERSE REACTIONS The most frequent reactions to metaxalone include: CNS: drowsiness, dizziness, headache, and nervousness or “irritability”; Digestive: nausea, vomiting, gastrointestinal upset. Other adverse reactions are: Immune System: hypersensitivity reaction, rash with or without pruritus; Hematologic: leukopenia; hemolytic anemia; Hepatobiliary: jaundice. Though rare, anaphylactoid reactions have been reported with metaxalone.

🔄 Drug Interactions 38 words ▾

Drug Interactions The sedative effects of metaxalone and other CNS depressants (e.g., alcohol, alcohol, benzodiazepines, opioids, tricyclic antidepressants) may be additive. Therefore, caution should be exercised with patients who take more than one of these CNS depressants simultaneously.

🤰 Pregnancy 97 words ▾

Pregnancy Reproduction studies in rats have not revealed evidence of impaired fertility or harm to the fetus due to metaxalone. Post marketing experience has not revealed evidence of fetal injury, but such experience cannot exclude the possibility of infrequent or subtle damage to the human fetus. Safe use of metaxalone has not been established with regard to possible adverse effects upon fetal development.

Therefore, metaxalone tablets should not be used in women who are or may become pregnant and particularly during early pregnancy unless, in the judgement of the physician, the potential benefits outweigh the possible hazards.

🧒 Pediatric Use 17 words ▾

Pediatric Use Safety and effectiveness in children 12 years of age and below have not been established.

🆘 Overdosage 88 words ▾

OVERDOSAGE Deaths by deliberate or accidental overdose have occurred with metaxalone, particularly in combination with antidepressants, and have been reported with this class of drug in combination with alcohol. When determining the LD 50 in rats and mice, progressive sedation, hypnosis and finally respiratory failure were noted as the dosage increased. In dogs, no LD 50 could be determined as the higher doses produced an emetic action in 15 to 30 minutes.

Treatment - Gastric lavage and supportive therapy. Consultation with a regional poison control center is recommended.

🧬 Clinical Pharmacology ~3 min read ▾

CLINICAL PHARMACOLOGY 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. Metaxalone has no direct action on the contractile mechanism of striated muscle, the motor end plate or the nerve fiber. Pharmacokinetics The pharmacokinetics of metaxalone have been evaluated in healthy adult volunteers after single dose administration of metaxalone under fasted and fed conditions at doses ranging from 400 mg to 800 mg.

Absorption Peak plasma concentrations of metaxalone occur approximately 3 hours after a 400 mg oral dose under fasted conditions. Thereafter, metaxalone concentrations decline log-linearly with a terminal half-life of 9.0 ± 4.8 hours. Doubling the dose of metaxalone from 400 mg to 800 mg results in a roughly proportional increase in metaxalone exposure as indicated by peak plasma concentrations (C max ) and area under the curve (AUC).

Dose proportionality at doses above 800 mg has not been studied. The absolute bioavailability of metaxalone is not known. The single-dose pharmacokinetic parameters of metaxalone in two groups of healthy volunteers are shown in Table 1.

Table 1: Mean (%CV) Metaxalone Pharmacokinetic Parameters Dose (mg) C max (ng/mL) T max (h) AUC ∞ (ng•h/mL) t ½ (h) CL/F (L/h) 400 1 983 (53) 3.3 (35) 7479 (51) 9.0 (53) 68 (50) 800 2 1816 (43) 3.0 (39) 15044 (46) 8.0 (58) 66 (51) 1 Subjects received 1x400 mg tablet under fasted conditions (N=42) 2 Subjects received 2x400 mg tablets under fasted conditions (N=59) Food Effects A randomized, two-way, crossover study was conducted in 42 healthy volunteers (31 males, 11 females) administered one 400 mg metaxalone tablet under fasted conditions and following a standard high-fat breakfast.

Subjects ranged in age from 18 to 48 years (mean age = 23.5 ± 5.7 years). Compared to fasted conditions, the presence of a high fat meal at the time of drug administration increased C max by 177.5% and increased AUC (AUC 0-t , AUC ∞ ) by 123.5% and 115.4%, respectively. Time-to-peak concentration (T max ) was also delayed (4.3 h versus 3.3 h) and terminal half-life was decreased (2.4 h versus 9.0 h) under fed conditions compared to fasted.

In a second food effect study of similar design, two 400 mg metaxalone tablets (800 mg) were administered to healthy volunteers (N=59, 37 males, 22 females), ranging in age from 18 to 50 years (mean age = 25.6± 8.7 years). Compared to fasted conditions, the presence of a high fat meal at the time of drug administration increased C max by 193.6% and increased AUC (AUC 0-t , AUC ∞ ) by 146.4% and 142.2%, respectively. Time-to-peak concentration (T max ) was also delayed (4.9 h versus 3.0 h) and terminal half-life was decreased (4.2 h versus 8.0 h) under fed conditions compared to fasted conditions.

Similar food effect results were observed in the above study when one metaxalone 800 mg tablet was administered in place of two metaxalone 400 mg tablets. The increase in metaxalone exposure coinciding with a reduction in half-life may be attributed to more complete absorption of metaxalone in the presence of a high fat meal (Figure 1). figure 1 Distribution, Metabolism, and Excretion Although plasma protein binding and absolute bioavailability of metaxalone are not known, the apparent volume of distribution (V/F ~ 800 L) and lipophilicity (log P = 2.42) of metaxalone suggest that the drug is extensively distributed in the tissues.

Metaxalone is metabolized by the liver and excreted in the urine as unidentified metabolites. Hepatic Cytochrome P450 enzymes play a role in the metabolism of metaxalone. Specifically, CYP1A2, CYP2D6, CYP2E1, and CYP3A4 and, to a lesser extent, CYP2C8, CYP2C9, and CYP2C19 appear to metabolize metaxalone.

Metaxalone does not significantly inhibit major CYP enzymes such as CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4. Metaxalone does not significantly induce major CYP enzymes such as CYP1A2, CY… [Excerpted — this section continues on DailyMed.]

🧬 Mechanism of Action 45 words ▾

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. Metaxalone has no direct action on the contractile mechanism of striated muscle, the motor end plate or the nerve fiber.

📦 How Supplied / Storage and Handling 123 words ▾

HOW SUPPLIED Metaxalone is available as an 800 mg , light pink to pink, capsule shaped, scored uncoated tablet with debossing ‘AN’ on the left side of the scoring and ‘553’ on the right side of the scoring. Other side of the tablet is plain. They are available as follows: Bottles of 10: NDC 63187-490-10 Bottles of 30: NDC 63187-490-30 Bottles of 60: NDC 63187-490-60 Bottles of 90: NDC 63187-490-90 Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [See USP Controlled Room Temperature].

Rx Only Manufactured By: Amneal Pharmaceuticals Co. (I) Pvt. Ltd.

Ahmedabad, INDIA 382220 Distributed By: Amneal Pharmaceuticals Glasgow, KY 42141 Repackaged By: Proficient Rx LP Thousand Oaks, CA 91320 Rev. 05-2012

📋 Description 107 words ▾

DESCRIPTION Metaxalone is available as an 800 mg, light pink to pink, capsule shaped, scored uncoated tablet. Chemically, metaxalone is 5-[(3,5- dimethylphenoxy) methyl]-2-oxazolidinone. The empirical formula is C 12 H 15 NO 3 , which corresponds to a molecular weight of 221.25.

The structural formula is: Metaxalone is a white to almost white, odorless crystalline powder freely soluble in chloroform, soluble in methanol and in 96% ethanol, but practically insoluble in ether or water. Each tablet contains 800 mg metaxalone and the following inactive ingredients: calcium carbonate, FD&C Red #40, hypromellose, lactose monohydrate, microcrystalline cellulose, povidone, silicone dioxide, sodium starch glycolate and sodium stearyl fumarate. chemical structure

💬 Information for Patients 34 words ▾

Information for Patients Metaxalone may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or driving a motor vehicle, especially when used with alcohol or other CNS depressants.

⚠️ Precautions ~1 min read ▾

PRECAUTIONS Metaxalone should be administered with great care to patients with pre-existing liver damage. Serial liver function studies should be performed in these patients. False-positive Benedict’s tests, due to an unknown reducing substance, have been noted.

A glucose-specific test will differentiate findings. Taking metaxalone with food may enhance general CNS depression; elderly patients may be especially susceptible to this CNS effect. (See CLINICAL PHARMACOLOGY: Pharmacokinetics and PRECAUTIONS: Information for Patients section).

Information for Patients Metaxalone may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or driving a motor vehicle, especially when used with alcohol or other CNS depressants. Drug Interactions The sedative effects of metaxalone and other CNS depressants (e.g., alcohol, alcohol, benzodiazepines, opioids, tricyclic antidepressants) may be additive. Therefore, caution should be exercised with patients who take more than one of these CNS depressants simultaneously.

Carcinogenesis, Mutagenesis, Impairment of Fertility The carcinogenic potential of metaxalone has not been determined. Pregnancy Reproduction studies in rats have not revealed evidence of impaired fertility or harm to the fetus due to metaxalone. Post marketing experience has not revealed evidence of fetal injury, but such experience cannot exclude the possibility of infrequent or subtle damage to the human fetus.

Safe use of metaxalone has not been established with regard to possible adverse effects upon fetal development. Therefore, metaxalone tablets should not be used in women who are or may become pregnant and particularly during early pregnancy unless, in the judgement of the physician, the potential benefits outweigh the possible hazards. Nursing Mothers It is not known whether this drug is secreted in human milk.

As a general rule, nursing should not be undertaken while a patient is on a drug since many drugs are excreted in human milk. Pediatric Use Safety and effectiveness in children 12 years of age and below have not been established.

🍼 Nursing Mothers 38 words ▾

Nursing Mothers It is not known whether this drug is secreted in human milk. As a general rule, nursing should not be undertaken while a patient is on a drug since many drugs are excreted in human milk.

🧬 Pharmacokinetics ~2 min read ▾

Pharmacokinetics The pharmacokinetics of metaxalone have been evaluated in healthy adult volunteers after single dose administration of metaxalone under fasted and fed conditions at doses ranging from 400 mg to 800 mg.

Pharmacokinetics in Special Populations Age: The effects of age on the pharmacokinetics of metaxalone were determined following single administration of two 400 mg tablets (800 mg) under fasted and fed conditions. The results were analyzed separately, as well as in combination with the results from three other studies. Using the combined data, the results indicate that the pharmacokinetics of metaxalone are significantly more affected by age under fasted conditions than under fed conditions, with bioavailability under fasted conditions increasing with age.

The bioavailability of metaxalone under fasted and fed conditions in three groups of healthy volunteers of varying age is shown in Table 2. Table 2: Mean (%CV) Pharmacokinetic Parameters Following Single Administration of Two 400 mg Metaxalone Tablets (800 mg) under Fasted and Fed Conditions Younger Volunteers Older Volunteers Age (years) 25.6 ± 8.7 39.3 ± 10.8 71.5 ±

5.0N 59 21 23 Food Fasted Fed Fasted Fed Fasted Fed C max (ng/mL) 1816 (43) 3510 (41) 2719 (46) 2915 (55) 3168 (43) 3680 (59) T max (h) 3.0 (39) 4.9 (48) 3.0 (40) 8.7 (91) 2.6 (30) 6.5 (67) AUC 0-t (ng·h/mL) 14531 (47) 20683 (41) 19836 (40) 20482 (37) 23797 (45) 24340 (48) AUC ∞ (ng·h/mL) 15045 (46) 20833 (41) 20490 (39) 20815 (37) 24194 (44) 24704 (47) Gender: The effect of gender on the pharmacokinetics of metaxalone was assessed in an open label study, in which 48 healthy adult volunteers (24 males, 24 females) were administered two metaxalone 400 mg tablets (800 mg) under fasted conditions.

The bioavailability of metaxalone was significantly higher in females compared to males as evidenced by C max (2115 ng/mL versus 1335 ng/mL) and AUC ∞ (17884 ng·h/mL versus 10328 ng·h/mL). The mean half-life was 11.1 hours in females and 7.6 hours in males. The apparent volume of distribution of metaxalone was approximately 22% higher in males than in females, but not significantly different when adjusted for body weight.

Similar findings were also seen when the previously described combined dataset was used in the analysis. Hepatic/Renal Insufficiency: The impact of hepatic and renal disease on the pharmacokinetics of metaxalone has not been determined. In the absence of such information, metaxalone should be used with caution in patients with hepatic and/or renal impairment.

📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 14 words ▾

Carcinogenesis, Mutagenesis, Impairment of Fertility The carcinogenic potential of metaxalone has not been determined.

📄 Package Label / Principal Display Panel 4 words ▾

PRINCIPAL DISPLAY PANEL 63187-490-30

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗

Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Metaxalone — the program that covers self-administered drugs. 8 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Metaxalone. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$1.81M
Claims incl. refills
18.6K
Beneficiaries
13K
Spend / beneficiary
$138.82
Spend / claim
$97.57
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos ✓ Available
Inactive ingredients (structured) ✓ Available
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data ✓ Available
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The form printed on the packaging and shown on DailyMed is the one the FDA registered. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero and the dashes are dropped. The Identity section at the top of this page lists each form of this code.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Proficient Rx LP. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 3 other package presentations of this same product, including 10 tablets (63187-0490-10), 30 tablets (63187-0490-30), 90 tablets (63187-0490-90). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Proficient Rx LP is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.
← 63187-0489-20 · Proficient 63187-0491-20 · Proficient →
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.