Dantrolene: uses, dosing, side effects & brands
Dantrolene is a skeletal muscle relaxant sold in the U.S. under one brand, for cerebral infarction, cerebral palsy and malignant hyperthermia. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Skeletal Muscle Relaxant
- Treats (across its forms)
- Cerebral Infarction, Cerebral Palsy and Malignant Hyperthermia
- Available as
- Capsule · Injectable
- Sold as
- Dantrium
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- What the pharmacy pays
- about $14 for a 30-count supply — not your price
How dantrolene is dosed
From the FDA label for Dantrium (application NDA018264). Other dantrolene products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
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…
Dantrolene side effects
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…
Who shouldn’t take dantrolene
None.
Dantrolene 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.
Every dantrolene product we track (1)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
Only one: Dantrium.
What dantrolene pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| G441;G441 | 25 mg | yellow, green | capsule | — |
| Dantrium;50;mg;0149;0031 | 50 mg | orange, brown | capsule | — |
| G441;G441 | 25 mg | yellow, green | capsule | — |
| G442;G442 | 50 mg | yellow, blue | capsule | — |
| G443;G443 | 100 mg | yellow, red | capsule | — |
| Dantirum;100;mg;0149;0033 | 100 mg | orange, brown | capsule | — |
How long dantrolene keeps
The date on a sealed pack is not the only one: some dantrolene labels start a second clock once the product is opened or mixed, as short as 6 hours.
Does dantrolene expire? The in-use limits and storage rules from its labelsDantrolene and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for dantrolene: levels in milk, effects in breastfed infants, and the drugs it would consider insteadBecause no information is available on the long-term use of dantrolene during breastfeeding, an alternate drug may be preferred, especially while nursing a newborn or preterm infant. After short-term use, the drug would be expected to be eliminated from milk in 1 to 2 days.
National Institute of Child Health and Human Development, record revised March 17, 2021. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about dantrolene
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 426 reports naming dantrolene, and the FDA flagged 85% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- neuroleptic malignant syndrome48 reports
- respiratory failure36 reports
- asthenia30 reports
- muscular weakness30 reports
- pyrexia30 reports
- convulsion27 reports
- diarrhoea24 reports
- fatigue23 reports
Read these as a signal, not a rate. A report does not mean dantrolene caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is dantrolene?
Dantrium Intravenous is a sterile, non-pyrogenic, lyophilized formulation of dantrolene sodium for injection.
What kind of drug is dantrolene?
The FDA classifies dantrolene as a skeletal muscle relaxant. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take dantrolene with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run dantrolene against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What forms does dantrolene come in?
Across the brands we track, dantrolene is currently marketed as capsule and injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic dantrolene?
We do not currently list a generic-labelled dantrolene product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Dantrolene: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/dantrolene
- MLA
- “Dantrolene: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/dantrolene.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for dantrolene on DailyMed (NIH) ↗.