Prescription medicine
Dantrolene Brand names: Dantrium, Ryanodex, Revonto
Dantrolene (Ryanodex) is a prescription medicine with an FDA approval on record since 1974. FDA's NDC Directory lists it from 10 generic labelers, and pharmacies paid $0.409 per dantrolene sodium 25 mg capsule in the October 7, 2026 NADAC survey.
- Generic listed
- Boxed warning
Check it at the source: the dantrolene FDA label on DailyMed (effective August 21, 2026, Par Health USA, LLC); the NDA 17443 record on Drugs@FDA; every dantrolene label on DailyMed.
Highlights of the record
FDA label of August 21, 2026; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026; NADAC October 7, 2026
Dantrolene sodium has a potential for hepatotoxicity, and should not be used in conditions other than those recommended. Symptomatic hepatitis (fatal and non-fatal) has been reported at various dose levels of the drug. The incidence reported in patients taking up to 400 mg/day is much lower than in those taking doses of 800 mg or more per day. Even sporadic short courses of these higher dose levels within a treatment regimen markedly increased the risk of serious hepatic injury. Liver dysfunction as evidenced by blood chemical abnormalities alone (liver enzyme elevations) has been observed in patients exposed to dantrolene sodium for varying periods of time. Overt hepatitis has occurred at varying intervals after initiation of therapy, but has been most frequently observed between the third and twelfth month of therapy. The risk of hepatic injury appears to be greater in females, in patients over 35 years of age, and in patients taking other medication(s) in addition to dantrolene sodium. Spontaneous reports suggest a higher proportion of hepatic events with fatal outcome in elderly patients receiving dantrolene sodium. However, the majority of these cases were complicated with confounding factors such as intercurrent illnesses and/or concomitant potentially hepatotoxic medications (see Geriatric Use subsection). […]
Used for
From the label: indications and usageIn Chronic Spasticity: Dantrolene sodium is indicated in controlling the manifestations of clinical spasticity resulting from upper motor neuron disorders (e.g., spinal cord injury, stroke, cerebral palsy, or multiple sclerosis).
Forms and strengths
- 20 mg
- 25 mg
- 50 mg
- 100 mg
- 20 mg/60ml
- 250 mg/5ml
Capsule; injection (powder) (lyophilized) for solution; injection (suspension); injection; injection (powder) for solution.
On the market
- Earliest approval on file
- January 15, 1974 Dantrium, Ph Health; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- 5 first March 1, 2005; 4 with a marketed status in Drugs@FDA
- Labelers listed (NDC)
- 13 of which 10 under generic applications, 2 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- $0.409 per capsule Dantrolene sodium 25 mg capsule
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- 3 since 2014 0 Class I among all firms' recalls; latest April 13, 2022
- FAERS reports
- 1,745 through July 30, 2026
What is dantrolene used for?
From the label: indications and usageIn Chronic Spasticity: Dantrolene sodium is indicated in controlling the manifestations of clinical spasticity resulting from upper motor neuron disorders (e.g., spinal cord injury, stroke, cerebral palsy, or multiple sclerosis). It is of particular benefit to the patient whose functional rehabilitation has been retarded by the sequelae of spasticity. Such patients must have presumably reversible spasticity where relief of spasticity will aid in restoring residual function. Dantrolene sodium is not indicated in the treatment of skeletal muscle spasm resulting from rheumatic disorders. […]
Conditions named in the indications of dantrolene's FDA labels, with every medicine labeled for each:
FDA pharmacologic class: Skeletal Muscle Relaxant.
Source: FDA drug label (dantrolene sodium), Par Health USA, LLC, effective August 21, 2026 (SPL set 11689f56-15e0-4350-b53f-ae96e5994fea), via openFDA; the full label on DailyMed
Is there a generic for dantrolene (Ryanodex)?
The FDA approved the first generic dantrolene on March 1, 2005. 5 generic applications are approved; 4 of them carry a current (not discontinued) marketing status in Drugs@FDA; that status is not evidence that the generic is on sale.
FDA's NDC Directory lists dantrolene from 10 labelers under a generic (ANDA) application and from 2 brand labelers. A listing means the company has registered the product for sale; it does not show that every pharmacy stocks it.
- 1974 earliest approval on file
- 2005 first generic approved
- red ticks recalls
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What do pharmacies pay for dantrolene (Ryanodex)?
In CMS's NADAC survey of October 7, 2026, pharmacies paid $0.409 per Dantrolene sodium 25 mg capsule, up 3% from $0.395 on October 8, 2025. The chart's scale runs from the lowest to the highest price shown, not from zero. NADAC is what retail pharmacies paid their wholesalers, per unit, in CMS's monthly survey; what a patient pays depends on insurance and the pharmacy.
- Dantrolene sodium 25 mg capsule (generic)
| Strength and form | Brand or generic | Pharmacy cost | 30 tablets, or one pen or vial | 12-month change |
|---|---|---|---|---|
| Dantrolene sodium 100 mg capsule | Generic | $1.01 per capsule | $30.22 | +11% |
| Dantrolene sodium 25 mg capsule | Generic | $0.409 per capsule | $12.26 | +3% |
| Dantrolene sodium 50 mg capsule | Generic | $0.554 per capsule | $16.61 | -22% |
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price
Has dantrolene been recalled?
The FDA's Enforcement Report lists 3 recalls naming dantrolene since 2014: 0 Class I (the most serious), 3 Class II, 0 Class III; 0 still ongoing. A recall names products and lots, not every product of the medicine.
| Started | Class | Company | Reason |
|---|---|---|---|
| April 13, 2022 | Class II | Mckesson Medical-Surgical Inc. Corporate Office | cGMP deviations: Temperature abuse |
| November 14, 2014 | Class II | Attix Pharmaceuticals | Penicillin Cross Contamination: All lots of all products repackaged and distributed between 01/05/12 and 02/12/15 are being recalled because they were … |
Source: FDA Enforcement Report (drug recalls) via openFDA, through October 8, 2026
What does the dantrolene label say about other medicines?
The dantrolene label names 4 other medicines in its interaction, contraindication or warning sections. The labels of 8 other medicines name dantrolene. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Diazepam | drug interactions | Binding to plasma protein is not significantly altered by diazepam, diphenylhydantoin, or phenylbutazone. |
| Phenobarbital | drug interactions | However, neither phenobarbital nor diazepam appears to affect Dantrium metabolism. |
| Verapamil | drug interactions | Cardiovascular collapse in patients treated simultaneously with verapamil and Dantrolene Sodium is rare. |
| Warfarin | drug interactions | Binding to plasma proteins is reduced by warfarin and clofibrate and increased by tolbutamide. |
Other labels that name dantrolene
Source: FDA drug label (dantrolene sodium), Par Health USA, LLC, effective August 21, 2026 (SPL set 11689f56-15e0-4350-b53f-ae96e5994fea), via openFDA; the full label on DailyMed
What do FAERS reports show for dantrolene?
The FDA Adverse Event Reporting System holds 1,745 reports that list dantrolene among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 198 are coded as a death and 854 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What else is labeled for the same conditions as dantrolene?
8 other medicines are given the same way (oral) and in the same FDA class as dantrolene or labeled mainly for the same use (muscle spasms and spasticity), the same class first. Muscle spasms and spasticity lists all 12 medicines labeled for it, by any route. They are listed as records, not as substitutes: whether one can replace another is a prescriber's decision.
| Medicine | Shared indication | Generic labelers (oral) | Pharmacy cost | Shortage |
|---|---|---|---|---|
| Cyclobenzaprine | Muscle spasms and spasticity | 60 labelers | $0.0171 per tablet 10 mg tablet | No current entry |
| Baclofen | Muscle spasms and spasticity | 52 labelers | $0.032 per tablet 10 mg tablet | No current entry |
| Tizanidine | Muscle spasms and spasticity | 51 labelers | $0.0331 per tablet 4 mg tablet | No current entry |
| Methocarbamol | Muscle spasms and spasticity | 54 labelers | $0.0395 per tablet 500 mg tablet | No current entry |
| Metaxalone | Muscle spasms and spasticity | 33 labelers | $0.452 per tablet 800 mg tablet | No current entry |
| Carisoprodol | Muscle spasms and spasticity | 24 labelers | $0.0706 per tablet 350 mg tablet | No current entry |
| Chlorzoxazone | Muscle spasms and spasticity | 19 labelers | $0.210 per tablet 500 mg tablet | No current entry |
| Orphenadrine | Muscle spasms and spasticity | 14 labelers | $0.454 per tablet 100 mg tablet | No current entry |
Every medicine labeled for the same conditions as dantrolene
Source: FDA drug labels (indications), NDC Directory, NADAC of October 7, 2026, FDA shortages (October 8, 2026)
How does dantrolene compare with medicines for the same use?
3 side-by-side pages set dantrolene beside a medicine whose label shares a use: approvals, generics, pharmacy cost, warnings and supply.
What next?
- Alternatives to dantrolene
- 8 medicines for the same use
- Dantrolene side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other