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Dantrium dantrolene sodium 20 mg/60mL Injection — NDC 42023-0123-06 package photo
Label image from the product's FDA listing (DailyMed) — may show a different pack size or an older label revision.

Dantrium dantrolene sodium 20 mg/60mL Injection — NDC 42023-123-06 (Billing 42023-0123-06)

by Par Health USA, LLC · 6 VIAL in 1 CARTON / 60 mL in 1 VIAL

This is a package of Dantrium dantrolene sodium 20 mg/60mL Injection from Par Health USA, LLC, marketed since Apr 2009 and currently FDA-listed. It is this product's only package size.

NDC 42023-0123-06
🏷️ FDA NDC (as labeled) 42023-123-06 billing pads the product segment with a zero
Rx only Brand On market Non-controlled ⇄ Compare with another NDC
🗂️ FDA directory synced Oct 8, 2026 · this listing last changed Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

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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 42023-123-06 alone.

Record
FDA NDC Directory package listing · Human prescription drug
Code segments
42023 labeler · 123 product · 06 package
Package marketed since
Apr 20, 2009
Sample package
No — commercial package
Listing certified through
Dec 31, 2027
Barcode (UPC-A, from the NDC)
3 4202312306 0
FDA record last changed
Jul 24, 2026

Identity & classification

Regulatory identifiers FDA, NLM and CMS codes for this package

FDA NDC (as labeled) 42023-123-06
Product NDC 42023-123
11-digit billing NDC 42023012306
NCPDP billing unit EA — each (per item)
RxCUI 856696, 856698
UNII 287M0347EV
Application # NDA018264
SPL Set ID 4df35098-8702-46be-ac67-30cfdf1aa570
Established class (EPC) Skeletal Muscle Relaxant
Physiologic effect Decreased Striated Muscle Contraction; Decreased Striated Muscle Tone
DEA schedule Non-controlled
Marketing category NDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2009-04-20
Route INTRAVENOUS
Dosage form INJECTION
Substance DANTROLENE SODIUM
TE code (Orange Book) AP · RLD · RS

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

GPI-14 75200010102105
GPI class Dantrium
GCN Seq No 004669
GCN 17950
HICL code 001947
Ingredient (HICL) Dantrolene Sodium
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 12:20.08.00
AHFS class Direct-Acting Skeletal Muscle Relaxants
FDB label name DANTRIUM 20 MG VIAL
FDB brand name Dantrium
Legend status F — Federal legend — prescription drug or device
Quick answers
  • GSN (GCN sequence number): 004669
  • GCN: 17950
  • GPI-14 (Medi-Span): 75200010102105
  • HICL (First Databank): 001947
  • AHFS class code: 12:20.08.00
  • RxCUI (RxNorm): 856696
Why two NDCs? The FDA registers this code as 42023-123-06 — 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 → 42023-0123-06. 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 Skeletal Muscle Relaxant class.

Pharmacologic class Skeletal Muscle Relaxant
Drug family (ATC) Dantrolene and derivatives
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 DANTRIUM 20 MG VIAL Ingredient Dantrolene Sodium
📗 Our plain-language guide HelloPharmacist
  • Dantrolene is used for two main things. If you're taking the capsules (Dantrium or Dantrolene Sodium), it's most likely to help control muscle stiffness and spasms caused by condit...
  • The most serious risk is liver damage. Watch for yellowing of your skin or the whites of your eyes, very dark urine, persistent nausea, or pain in the upper right side of your abdo...
  • What are the most important side effects I should watch for?
  • Dantrolene can cause liver damage — and this is the number one safety concern with long-term use. Regular blood tests (liver function tests) are the only way to catch a problem ear...
📖 Read our full Dantrolene 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 · quarterly No Part D plan price is available for this NDC in our data.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
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
42023-0123-06 You're viewing this Main listing 6 VIAL in 1 CARTON / 60 mL in 1 VIAL 2009-04-20 — Active

Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Dantrolene 20 mg 00143-9297-01 Hikma 1 injection — AP FDA listed —
Dantrium 20 mg/60mLthis 42023-0123-06 Par 6 vials — AP FDA listed —
Revonto 20 mg/60mL 78670-0003-67 USWM, 6 vials — AP FDA listed —
Revonto 20 mg/60mL 84549-0003-67 ProPharma 60 ml — AP FDA listed —
About this product: this is the brand-name version. Some generic versions are approved by the FDA, but we could not confirm current pharmacy availability from our pricing/market data.
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

🏛️
2009
On the market since
Apr 2009
📍
2026
Currently FDA-listed
17 years listed
🔒
·
Generic approved (availability unconfirmed)
see note
🔒Generic approved by FDA, but pharmacy availability is not confirmed

The FDA lists approved generic versions of this medicine, but that does not always mean a pharmacy can get one today. Patent rules, launch agreements, supply and pricing can affect when generics actually arrive.

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.

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 Dantrolene 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 3OWL53L36A
    A natural sugar alcohol derived from seaweed or synthesized in the lab. It's used as a filler to add bulk, a sweetener in sugar-free formulas, and a disintegrant to help tablets break apart in the stomach.
  • UNII 55X04QC32I
    A strong alkaline chemical used to adjust and maintain the pH balance of liquid medicines. It helps keep the medicine stable and ensures it stays effective during storage.

2 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

LabelerPar Health USA, LLC
Application holderPH HEALTH LTD
FDA applicationNDA018264 (NDA)
Labeler code42023
First marketedApr 2009
Product typeHuman Prescription Drug
Portfolio216 products on file

More NDCs from Par Health USA, LLC labeler code 42023

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 🧓 Geriatric Use 🆘 Overdosage 🧬 Clinical Pharmacology 📦 How Supplied / Storage and Handling 📦 Storage and Handling 📋 Description 💬 Information for Patients ⚠️ Precautions 🍼 Nursing Mothers 📄 Carcinogenesis, Mutagenesis, Impairment of Fertility 📄 Package Label / Principal Display Panel
🎯 Indications and Usage 113 words ▾

INDICATIONS AND USAGE: Dantrium Intravenous is indicated, along with appropriate supportive measures, for the management of the fulminant hypermetabolism of skeletal muscle characteristic of malignant hyperthermia crises in patients of all ages. Dantrium Intravenous should be administered by continuous rapid intravenous push as soon as the malignant hyperthermia reaction is recognized (i.e., tachycardia, tachypnea, central venous desaturation, hypercarbia, metabolic acidosis, skeletal muscle rigidity, increased utilization of anesthesia circuit carbon dioxide absorber, cyanosis and mottling of the skin, and, in many cases, fever).

Dantrium Intravenous is also indicated preoperatively, and sometimes postoperatively, to prevent or attenuate the development of clinical and laboratory signs of malignant hyperthermia in individuals judged to be malignant hyperthermia susceptible.

⏱️ Dosage and Administration ~3 min read ▾

DOSAGE AND ADMINISTRATION: As soon as the malignant hyperthermia reaction is recognized, all anesthetic agents should be discontinued; the administration of 100% oxygen is recommended. Dantrium Intravenous should be administered by continuous rapid intravenous push beginning at a minimum dose of 1 mg/kg, and continuing until symptoms subside or the maximum cumulative dose of 10 mg/kg has been reached. If the physiologic and metabolic abnormalities reappear, the regimen may be repeated.

It is important to note that administration of Dantrium Intravenous should be continuous until symptoms subside. The effective dose to reverse the crisis is directly dependent upon the individual's degree of susceptibility to malignant hyperthermia, the amount and time of exposure to the triggering agent, and the time elapsed between onset of the crisis and initiation of treatment. Pediatric Dose: Experience to date indicates that the dose of Dantrium Intravenous for pediatric patients is the same as for adults.

Preoperatively: Dantrium Intravenous and/or Dantrium Capsules may be administered preoperatively to patients judged malignant hyperthermia susceptible as part of the overall patient management to prevent or attenuate the development of clinical and laboratory signs of malignant hyperthermia. Dantrium Intravenous: The recommended prophylactic dose of Dantrium Intravenous is 2.5 mg/kg, starting approximately 1-1/4 hours before anticipated anesthesia and infused over approximately 1 hour. This dose should prevent or attenuate the development of clinical and laboratory signs of malignant hyperthermia provided that the usual precautions, such as avoidance of established malignant hyperthermia triggering agents, are followed.

Additional Dantrium Intravenous may be indicated during anesthesia and surgery because of the appearance of early clinical and/or blood gas signs of malignant hyperthermia or because of prolonged surgery (see also CLINICAL PHARMACOLOGY , WARNINGS , and PRECAUTIONS ). Additional doses must be individualized. Oral Administration of Dantrium Capsules: Administer 4 to 8 mg/kg/day of oral Dantrium Capsules in three or four divided doses for 1 or 2 days prior to surgery, with the last dose being given with a minimum of water approximately 3 to 4 hours before scheduled surgery.

Adjustment can usually be made within the recommended dosage range to avoid incapacitation (weakness, drowsiness, etc.) or excessive gastrointestinal irritation (nausea and/or vomiting). See also the package insert for Dantrium Capsules . Post Crisis Follow-Up: Dantrium Capsules , 4 to 8 mg/kg/day, in four divided doses should be administered for 1 to 3 days following a malignant hyperthermia crisis to prevent recurrence of the manifestations of malignant hyperthermia.

Dantrium Intravenous may be used postoperatively to prevent or attenuate the recurrence of signs of malignant hyperthermia when oral administration of Dantrium Capsules is not practical. The dose of Dantrium Intravenous in the postoperative period must be individualized, starting with 1 mg/kg or more as the clinical situation dictates. PREPARATION: Each vial of Dantrium Intravenous should be reconstituted by adding 60 mL of sterile water for injection USP (without a bacteriostatic agent), and the vial shaken until the solution is clear.

5% Dextrose Injection USP, 0.9% Sodium Chloride Injection USP, and other acidic solutions are not compatible with Dantrium Intravenous and should not be used. The contents of the vial must be protected from direct light and used within 6 hours after reconstitution. Store reconstituted solutions between 15° to 30°C (59° to 86°F).

Reconstituted Dantrium Intravenous should not be transferred to large glass bottles for prophylactic infusion due to precipitate formation observed with the use of some glass bottles as reservoirs. For prophylactic infusion, the required number of individual vials of Dantrium Intravenous should be reconstituted as outlined above. The… [Excerpted — this section continues on DailyMed.]

⛔ Contraindications 2 words ▾

CONTRAINDICATIONS: None.

⚠️ Warnings 157 words ▾

WARNINGS: The use of Dantrium Intravenous in the management of malignant hyperthermia crisis is not a substitute for previously known supportive measures. These measures must be individualized, but it will usually be necessary to discontinue the suspect triggering agents, attend to increased oxygen requirements, manage the metabolic acidosis, institute cooling when necessary, monitor urinary output, and monitor for electrolyte imbalance. Since the effect of disease state and other drugs on Dantrium -related skeletal muscle weakness, including possible respiratory depression, cannot be predicted, patients who receive Dantrium Intravenous preoperatively should have vital signs monitored.

If patients judged malignant hyperthermia susceptible are administered intravenous or oral Dantrium preoperatively, anesthetic preparation must still follow a standard malignant hyperthermia susceptible regimen, including the avoidance of known triggering agents. Monitoring for early clinical and metabolic signs of malignant hyperthermia is indicated because attenuation of malignant hyperthermia, rather than prevention, is possible. These signs usually call for the administration of additional intravenous dantrolene.

🤒 Adverse Reactions ~2 min read ▾

ADVERSE REACTIONS: There have been occasional reports of death following malignant hyperthermia crisis even when treated with intravenous dantrolene; incidence figures are not available (the pre-dantrolene mortality of malignant hyperthermia crisis was approximately 50%). Most of these deaths can be accounted for by late recognition, delayed treatment, inadequate dosage, lack of supportive therapy, intercurrent disease and/or the development of delayed complications such as renal failure or disseminated intravascular coagulopathy.

In some cases there are insufficient data to completely rule out therapeutic failure of dantrolene. There are reports of fatality in malignant hyperthermia crisis, despite initial satisfactory response to intravenous dantrolene, which involve patients who could not be weaned from dantrolene after initial treatment. The administration of Dantrium Intravenous to human volunteers is associated with loss of grip strength and weakness in the legs, as well as drowsiness and dizziness.

The following adverse reactions are in approximate order of severity: There are rare reports of pulmonary edema developing during the treatment of malignant hyperthermia crisis in which the diluent volume and mannitol needed to deliver intravenous dantrolene possibly contributed. There have been reported cases of hepatotoxicity following the use of intravenous dantrolene products. Elevated liver enzymes have occurred hours to days following use of intravenous dantrolene, though many of these cases were observed in patients with comorbidities (e.g., critical illness).

There have been reports of thrombophlebitis following administration of intravenous dantrolene; actual incidence figures are not available. Tissue necrosis secondary to extravasation has been reported. There have been rare reports of urticaria and erythema possibly associated with the administration of Dantrium Intravenous .

There has been one case of anaphylaxis. Injection site reactions (pain, erythema, swelling), commonly due to extravasation, have been reported. The following events have been reported in patients receiving oral dantrolene: aplastic anemia, leukopenia, lymphocytic lymphoma, and heart failure.

(See package insert for Dantrium (dantrolene sodium) Capsules for a complete listing of adverse reactions.) The published literature has included some reports of Dantrium use in patients with Neuroleptic Malignant Syndrome (NMS). Dantrium Intravenous is not indicated for the treatment of NMS and patients may expire despite treatment with Dantrium Intravenous . For medical advice about adverse reactions contact your medical professional.

To report SUSPECTED ADVERSE REACTIONS, contact Par Health at 1-800-828-9393 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

🔄 Drug Interactions 120 words ▾

Drug Interactions: Dantrium is metabolized by the liver, and it is theoretically possible that its metabolism may be enhanced by drugs known to induce hepatic microsomal enzymes. However, neither phenobarbital nor diazepam appears to affect Dantrium metabolism. Binding to plasma protein is not significantly altered by diazepam, diphenylhydantoin, or phenylbutazone.

Binding to plasma proteins is reduced by warfarin and clofibrate and increased by tolbutamide. Cardiovascular collapse in association with marked hyperkalemia has been reported in patients receiving dantrolene in combination with calcium channel blockers. It is recommended that the combination of intravenous dantrolene sodium and calcium channel blockers, such as verapamil, not be used together during the management of malignant hyperthermia crisis.

Administration of dantrolene may potentiate vecuronium-induced neuromuscular block.

🤰 Pregnancy 64 words ▾

Pregnancy: Pregnancy Category C: Dantrium has been shown to be embryocidal in the rabbit and has been shown to decrease pup survival in the rat when given at doses seven times the human oral dose. There are no adequate and well-controlled studies in pregnant women. Dantrium Intravenous should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

🧒 Pediatric Use 21 words ▾

Pediatric Dose: Experience to date indicates that the dose of Dantrium Intravenous for pediatric patients is the same as for adults.

🧓 Geriatric Use 73 words ▾

Geriatric Use: Clinical studies of Dantrium Intravenous did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

🆘 Overdosage 161 words ▾

OVERDOSAGE: Because Dantrium Intravenous must be administered at a low concentration in a large volume of fluid, acute toxicity of Dantrium Intravenous could not be assessed in animals. In 14-day (subacute) studies, the intravenous formulation of Dantrium was relatively non-toxic to rats at doses of 10 mg/kg/day and 20 mg/kg/day. While 10 mg/kg/day in dogs for 14 days evoked little toxicity, 20 mg/kg/day for 14 days caused hepatic changes of questionable biologic significance.

Symptoms which may occur in case of overdose include, but are not limited to, muscular weakness and alterations in the state of consciousness (e.g., lethargy, coma), vomiting, diarrhea, and crystalluria. For acute overdosage, general supportive measures should be employed. Intravenous fluids should be administered in fairly large quantities to avert the possibility of crystalluria.

An adequate airway should be maintained and artificial resuscitation equipment should be at hand. Electrocardiographic monitoring should be instituted, and the patient carefully observed. The value of dialysis in Dantrium overdose is not known.

🧬 Clinical Pharmacology ~3 min read ▾

CLINICAL PHARMACOLOGY: In isolated nerve-muscle preparation, Dantrium has been shown to produce relaxation by affecting the contractile response of the muscle at a site beyond the myoneural junction. In skeletal muscle, Dantrium dissociates the excitation-contraction coupling, probably by interfering with the release of Ca++ from the sarcoplasmic reticulum. The administration of intravenous Dantrium to human volunteers is associated with loss of grip strength and weakness in the legs, as well as subjective CNS complaints (see also PRECAUTIONS, Information for Patients ).

Information concerning the passage of Dantrium across the blood-brain barrier is not available. In the anesthetic-induced malignant hyperthermia syndrome, evidence points to an intrinsic abnormality of skeletal muscle tissue. In affected humans, it has been postulated that "triggering agents" (e.g., general anesthetics and depolarizing neuromuscular blocking agents) produce a change within the cell which results in an elevated myoplasmic calcium.

This elevated myoplasmic calcium activates acute cellular catabolic processes that cascade to the malignant hyperthermia crisis. It is hypothesized that addition of Dantrium to the "triggered" malignant hyperthermic muscle cell reestablishes a normal level of ionized calcium in the myoplasm. Inhibition of calcium release from the sarcoplasmic reticulum by Dantrium reestablishes the myoplasmic calcium equilibrium, increasing the percentage of bound calcium.

In this way, physiologic, metabolic, and biochemical changes associated with the malignant hyperthermia crisis may be reversed or attenuated. Experimental results in malignant hyperthermia susceptible swine show that prophylactic administration of intravenous or oral dantrolene prevents or attenuates the development of vital sign and blood gas changes characteristic of malignant hyperthermia in a dose related manner. The efficacy of intravenous dantrolene in the treatment of human and porcine malignant hyperthermia crisis, when considered along with prophylactic experiments in malignant hyperthermia susceptible swine, lends support to prophylactic use of oral or intravenous dantrolene in malignant hyperthermia susceptible humans.

When prophylactic intravenous dantrolene is administered as directed, whole blood concentrations remain at a near steady state level for 3 or more hours after the infusion is completed. Clinical experience has shown that early vital sign and/or blood gas changes characteristic of malignant hyperthermia may appear during or after anesthesia and surgery despite the prophylactic use of dantrolene and adherence to currently accepted patient management practices. These signs are compatible with attenuated malignant hyperthermia and respond to the administration of additional intravenous dantrolene (see DOSAGE AND ADMINISTRATION ).

The administration of the recommended prophylactic dose of intravenous dantrolene to healthy volunteers was not associated with clinically significant cardiorespiratory changes. Specific metabolic pathways for the degradation and elimination of Dantrium in humans have been established. Dantrolene is found in measurable amounts in blood and urine.

Its major metabolites in body fluids are 5-hydroxy dantrolene and an acetylamino metabolite of dantrolene. Another metabolite with an unknown structure appears related to the latter. Dantrium may also undergo hydrolysis and subsequent oxidation forming nitrophenylfuroic acid.

The mean biologic half-life of Dantrium after intravenous administration is variable, between 4 to 8 hours under most experimental conditions. Based on assays of whole blood and plasma, slightly greater amounts of dantrolene are associated with red blood cells than with the plasma fraction of blood. Significant amounts of dantrolene are bound to plasma proteins, mostly albumin, and this binding is readily reversible.

Cardiopulmonary depression has not been observed in malignant hyperthermia susceptible sw… [Excerpted — this section continues on DailyMed.]

📦 How Supplied / Storage and Handling 69 words ▾

HOW SUPPLIED: Dantrium Intravenous ( NDC 42023-123-06) is available in vials containing a sterile lyophilized mixture of 20 mg dantrolene sodium, 3000 mg mannitol, and sufficient sodium hydroxide to yield a pH of approximately 9.5 when reconstituted with 60 mL sterile water for injection USP (without a bacteriostatic agent). Store unreconstituted product between 20° to 25°C (68° to 77°F). (See USP Controlled Room Temperature).

Avoid prolonged exposure to light.

📦 Storage and Handling 20 words ▾

Store unreconstituted product between 20° to 25°C (68° to 77°F). (See USP Controlled Room Temperature). Avoid prolonged exposure to light.

📋 Description 107 words ▾

DESCRIPTION: Dantrium Intravenous is a sterile, non-pyrogenic, lyophilized formulation of dantrolene sodium for injection. Dantrium Intravenous is supplied in 70 mL vials containing 20 mg dantrolene sodium, 3000 mg mannitol, and sufficient sodium hydroxide to yield a pH of approximately 9.5 when reconstituted with 60 mL sterile water for injection USP (without a bacteriostatic agent). Dantrium is classified as a direct-acting skeletal muscle relaxant.

Chemically, Dantrium is hydrated 1-[[[5-(4-nitrophenyl)-2-furanyl]methylene]amino]-2,4-imidazolidinedione sodium salt. The structural formula for the hydrated salt is: The hydrated salt contains approximately 15% water (3-1/2 moles) and has a molecular weight of 399. The anhydrous salt (dantrolene) has a molecular weight of 336.

Chemical structure

💬 Information for Patients 109 words ▾

Information for Patients: Based upon data in human volunteers, perioperatively, it is appropriate to tell patients who receive Dantrium Intravenous that symptoms of muscle weakness should be expected postoperatively (i.e., decrease in grip strength and weakness of leg muscles, especially walking down stairs). In addition, symptoms such as "lightheadedness" may be noted. Since some of these symptoms may persist for up to 48 hours, patients must not operate an automobile or engage in other hazardous activity during this time.

Caution is also indicated at meals on the day of administration because difficulty swallowing and choking has been reported. Caution should be exercised in the concomitant administration of tranquilizing agents.

⚠️ Precautions ~3 min read ▾

PRECAUTIONS: General: Care must be taken to prevent extravasation of Dantrium Intravenous solution into the surrounding tissues due to the high pH of the intravenous formulation and potential for tissue necrosis. When mannitol is used for prevention or treatment of late renal complications of malignant hyperthermia, the 3 g of mannitol needed to dissolve each 20 mg vial of Dantrium Intravenous should be taken into consideration. Information for Patients: Based upon data in human volunteers, perioperatively, it is appropriate to tell patients who receive Dantrium Intravenous that symptoms of muscle weakness should be expected postoperatively (i.e., decrease in grip strength and weakness of leg muscles, especially walking down stairs).

In addition, symptoms such as "lightheadedness" may be noted. Since some of these symptoms may persist for up to 48 hours, patients must not operate an automobile or engage in other hazardous activity during this time. Caution is also indicated at meals on the day of administration because difficulty swallowing and choking has been reported.

Caution should be exercised in the concomitant administration of tranquilizing agents. Drug Interactions: Dantrium is metabolized by the liver, and it is theoretically possible that its metabolism may be enhanced by drugs known to induce hepatic microsomal enzymes. However, neither phenobarbital nor diazepam appears to affect Dantrium metabolism.

Binding to plasma protein is not significantly altered by diazepam, diphenylhydantoin, or phenylbutazone. Binding to plasma proteins is reduced by warfarin and clofibrate and increased by tolbutamide. Cardiovascular collapse in association with marked hyperkalemia has been reported in patients receiving dantrolene in combination with calcium channel blockers.

It is recommended that the combination of intravenous dantrolene sodium and calcium channel blockers, such as verapamil, not be used together during the management of malignant hyperthermia crisis. Administration of dantrolene may potentiate vecuronium-induced neuromuscular block. Carcinogenesis, Mutagenesis, and Impairment of Fertility: Sprague-Dawley female rats fed Dantrium for 18 months at dosage levels of 15, 30, and 60 mg/kg/day showed an increased incidence of benign and malignant mammary tumors compared with concurrent controls.

At the highest dose level (approximately the same as the maximum recommended daily dose on a mg/m 2 basis), there was an increase in the incidence of benign hepatic lymphatic neoplasms. In a 30-month study in Sprague-Dawley rats fed dantrolene sodium, the highest dose level (approximately the same as the maximum recommended daily dose on a mg/m 2 basis) produced a decrease in the time of onset of mammary neoplasms. Female rats at the highest dose level showed an increased incidence of hepatic lymphangiomas and hepatic angiosarcomas.

The only drug-related effect seen in a 30-month study in Fischer-344 rats was a dose-related reduction in the time of onset of mammary and testicular tumors. A 24-month study in HaM/ICR mice revealed no evidence of carcinogenic activity. The significance of carcinogenicity data relative to use of Dantrium in humans is unknown.

Dantrolene sodium has produced positive results in the Ames S. Typhimurium bacterial mutagenesis assay in the presence and absence of a liver activating system. Dantrolene sodium administered to male and female rats at dose levels up to 45 mg/kg/day (approximately 1.4 times the maximum recommended daily dose on a mg/m 2 basis) showed no adverse effects on fertility or general reproductive performance.

Pregnancy: Pregnancy Category C: Dantrium has been shown to be embryocidal in the rabbit and has been shown to decrease pup survival in the rat when given at doses seven times the human oral dose. There are no adequate and well-controlled studies in pregnant women. Dantrium Intravenous should be used during pregnancy only if the potential benefit justifies the potential risk to the… [Excerpted — this section continues on DailyMed.]

🍼 Nursing Mothers 63 words ▾

Nursing Mothers: Dantrolene has been detected in human milk at low concentrations (less than 2 micrograms per mL) during repeat intravenous administration over 3 days. Because of the potential for serious adverse reactions in nursing infants from dantrolene, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

📄 Carcinogenesis, Mutagenesis, Impairment of Fertility ~1 min read ▾

Carcinogenesis, Mutagenesis, and Impairment of Fertility: Sprague-Dawley female rats fed Dantrium for 18 months at dosage levels of 15, 30, and 60 mg/kg/day showed an increased incidence of benign and malignant mammary tumors compared with concurrent controls. At the highest dose level (approximately the same as the maximum recommended daily dose on a mg/m 2 basis), there was an increase in the incidence of benign hepatic lymphatic neoplasms. In a 30-month study in Sprague-Dawley rats fed dantrolene sodium, the highest dose level (approximately the same as the maximum recommended daily dose on a mg/m 2 basis) produced a decrease in the time of onset of mammary neoplasms.

Female rats at the highest dose level showed an increased incidence of hepatic lymphangiomas and hepatic angiosarcomas. The only drug-related effect seen in a 30-month study in Fischer-344 rats was a dose-related reduction in the time of onset of mammary and testicular tumors. A 24-month study in HaM/ICR mice revealed no evidence of carcinogenic activity.

The significance of carcinogenicity data relative to use of Dantrium in humans is unknown. Dantrolene sodium has produced positive results in the Ames S. Typhimurium bacterial mutagenesis assay in the presence and absence of a liver activating system.

Dantrolene sodium administered to male and female rats at dose levels up to 45 mg/kg/day (approximately 1.4 times the maximum recommended daily dose on a mg/m 2 basis) showed no adverse effects on fertility or general reproductive performance.

📄 Package Label / Principal Display Panel 44 words ▾

PRINCIPAL DISPLAY PANEL - 20 mg Vial Carton 6 Vials Nonreturnable NDC 42023-123-06 20 mg Dantrium ® Intravenous (dantrolene sodium for injection) For treatment of malignant hyperthermia FOR INTRAVENOUS USE ONLY Rx Only This is a carton image of Dantrium Intravenous 20 mg vials.

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 · 2025 (Q1-Q4)

Medicare Part D (outpatient prescription) spending for Dantrium — the program that covers self-administered drugs. 1 manufacturer.
⚠️ 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 Dantrium. 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.
Total Part D spend
$4.3K
Claims incl. refills
29
Beneficiaries
—
Spend / beneficiary
—
Spend / claim
$148.10
💵 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 Par Health USA, LLC. Listing status can change — the directory data on this page refreshes weekly.
Who lists this product with the FDA?
Par Health USA, LLC 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.
← 42023-0119-25 · Par 42023-0124-01 · Endo →
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.