Dantrolene Sodium
Pronunciation: (dan-TROH-leen).
- Generic name
- Dantrolene sodium
- Brand names
- Revonto, Dantrolene Link, Dantrium, Dantrolene Sodium, Ryanodex, Dantrol
- Drug class
- Skeletal muscle relaxant
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What Dantrolene sodium is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Dantrolene sodium works
Mechanism-of-action detail beyond the recorded indications and dosing above was not captured as a separate field in the clinician-authored database record for this medicine; see how_to_take and professional_information.regional_dosing for the recorded clinical detail. (2)
What Dantrolene sodium is used for
Malignant hyperthermia (prevention in known/suspected susceptible patients before surgery, and to prevent recurrence after a crisis)
Malignant hyperthermia (prevention in known/suspected susceptible patients before surgery, and to prevent recurrence after a crisis) (2) (1)
Chronic muscle spasticity from upper motor neuron disorders (spinal cord injury, stroke, cerebral palsy, multiple sclerosis)
Chronic muscle spasticity from upper motor neuron disorders (spinal cord injury, stroke, cerebral palsy, multiple sclerosis) (2) (1)
Before taking Dantrolene sodium
Do not take / not appropriate for
- active hepatic disease (hepatitis, cirrhosis). (Contraindication) (1)
- use where spasticity itself maintains upright posture, balance, or otherwise provides functional benefit (i.e., treating the spasticity could reduce function — a clinical judgment call, not a patient-facing symptom-based contraindication). (Contraindication) (1)
Tell your clinician about
(1)How to take Dantrolene sodium
- Take dantrolene exactly as prescribed by your healthcare provider. Any change to your dose, including stopping treatment, must be made by your prescriber — do not change it yourself. Oral capsules should be swallowed whole with water. For IV use (malignant hyperthermia), dantrolene is reconstituted and administered by a healthcare professional in a medical facility. For chronic spasticity, the FDA label describes a structured weekly increase: 25 mg once daily for 7 days, then 25 mg three times daily for 7 days, then 50 mg three times daily for 7 days, then 100 mg three times daily (occasionally four times daily) from week 4 onward, to a maximum of 100 mg four times daily; your prescriber may discontinue treatment if there is no benefit after about 45 days. For malignant hyperthermia, oral dosing is used before surgery (4-8 mg/kg/day in 3-4 divided doses over 1-2 days, with the last dose about 3-4 hours before surgery) and after a crisis to prevent recurrence (4-8 mg/kg/day in 4 divided doses for 1-3 days); the clinician-authored database's separate IV crisis-treatment figures (2.5 mg/kg initial, repeated up to about 10 mg/kg total) describe emergency in-hospital IV treatment and were not independently confirmed by the oral-capsule label reviewed in this pass.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
If you miss a dose of Dantrolene, contact your prescriber or pharmacist for guidance on your next dose rather than deciding on your own whether to take, skip, or double it. Missed-dose handling can depend on why and how this medicine is being used.
Overdose
In case of overdose, seek emergency medical attention or call your local poison control center immediately. The FDA label describes overdose symptoms as muscular weakness, altered consciousness (including lethargy or coma), vomiting, diarrhea, and crystalluria; treatment is medical-facility supportive care, which may include gastric lavage and large-volume IV fluids to help prevent crystalluria. Liver toxicity and respiratory depression are listed as possible serious effects of dantrolene generally, but were not specifically established as overdose symptoms in the source reviewed. (1)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Drowsiness
Incidence: Reported in the clinician-authored database and corroborated by the FDA label as among the most frequent effects; frequency not numerically established
Dizziness
Incidence: Reported in the clinician-authored database and corroborated by the FDA label; frequency not numerically established
Diarrhea
Incidence: Reported in the clinician-authored database and corroborated by the FDA label; generally transient and occurring early in treatment, though severe diarrhea may require your prescriber to stop treatment
General weakness, malaise, or fatigue
Incidence: Reported in the clinician-authored database and corroborated by the FDA label as among the most frequent effects; frequency not numerically established
Nausea
Incidence: Reported in the clinician-authored database; this was not confirmed in the FDA label reviewed in this pass and is presented as DB-sourced pending further verification
Seizures
Incidence: Reported in the clinician-authored database; this was not confirmed in the FDA label reviewed in this pass and is presented as DB-sourced pending further verification, not as an externally corroborated common effect
Any sign of liver problems: yellowing of the skin or eyes (jaundice), dark urine, pale stools, or severe abdominal pain
What to do: Contact a healthcare professional promptly if this develops — this can be a sign of the boxed-warning liver-injury risk. (2) (1)
Persistent nausea or vomiting
What to do: Contact a healthcare professional promptly if this develops. (2)
Unusual tiredness or weakness beyond the expected mild fatigue
What to do: Contact a healthcare professional promptly if this develops. (2)
Severe or persistent diarrhea
What to do: Contact a healthcare professional promptly — your prescriber may need to stop treatment. (1)
Unusual bleeding or bruising, signs of infection (fever, sore throat), or breathing difficulty
What to do: Seek prompt medical attention — these can be signs of rare but serious blood, respiratory, or hypersensitivity reactions. (1)
Serious warnings
BOXED WARNING (hepatotoxicity) — serious
Symptoms: BOXED WARNING (hepatotoxicity): Fatal and non-fatal hepatitis has been reported with dantrolene at various dose levels, with risk rising sharply at doses of 800 mg or more per day. Onset typically occurs between the third and twelfth month of therapy. Risk is higher in women, in people over 35, and with certain concomitant medications (including estrogen). Liver-function blood tests are required before starting and at intervals during treatment.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2) (1)
Dantrolene should not be started if you have active liver disease (such as hepatitis or cirrhosis) — this is FDA-label confirmed — serious
Symptoms: Dantrolene should not be started if you have active liver disease (such as hepatitis or cirrhosis) — this is FDA-label confirmed. The clinician-authored database also lists known hypersensitivity to dantrolene as a reason not to start; this specific item was not independently confirmed in the FDA label facts reviewed and is presented as DB-sourced pending further verification. Tell your prescriber about any liver history or prior reaction before starting.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2) (1)
The FDA label also identifies a clinician-assessed functional boundary — serious
Symptoms: The FDA label also identifies a clinician-assessed functional boundary: dantrolene should not be used where the person's spasticity is helping maintain upright posture, balance, or another functional benefit, because relieving the spasticity could reduce function. This is a judgment your prescriber makes, not something to assess yourself.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Seek immediate medical attention if you experience signs of severe liver damage (such as yellowing of the skin or eyes, dark urine, or severe abdominal pain), severe allergic reactions (rash, itching, swelling, severe dizziness, trouble breathing), severe muscle weakness, difficulty breathing, or a fast heartbeat or signs of heart failure (the FDA label specifically lists tachycardia and heart failure among the reported cardiovascular effects) — serious
Symptoms: Seek immediate medical attention if you experience signs of severe liver damage (such as yellowing of the skin or eyes, dark urine, or severe abdominal pain), severe allergic reactions (rash, itching, swelling, severe dizziness, trouble breathing), severe muscle weakness, difficulty breathing, or a fast heartbeat or signs of heart failure (the FDA label specifically lists tachycardia and heart failure among the reported cardiovascular effects).
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Use caution in elderly patients and those with pre-existing liver or lung disease — serious
Symptoms: Use caution in elderly patients and those with pre-existing liver or lung disease; women and people over 35 have a higher documented risk of serious, sometimes fatal, liver injury.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (2) (1)
May cause drowsiness, dizziness, or muscle weakness — serious
Symptoms: May cause drowsiness, dizziness, or muscle weakness.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
The FDA label states dantrolene should not be used in nursing mothers, and should be given during pregnancy only if clearly needed, as adequate reproduction studies have not been conducted — serious
Symptoms: The FDA label states dantrolene should not be used in nursing mothers, and should be given during pregnancy only if clearly needed, as adequate reproduction studies have not been conducted.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Any change to your dantrolene treatment, including stopping it, must be planned and supervised by your prescriber — contact your prescriber about any concern with continuing treatment rather than changing or stopping it yourself — serious
Symptoms: Any change to your dantrolene treatment, including stopping it, must be planned and supervised by your prescriber — contact your prescriber about any concern with continuing treatment rather than changing or stopping it yourself.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Severe diarrhea may require your prescriber to stop treatment — serious
Symptoms: Severe diarrhea may require your prescriber to stop treatment; contact your prescriber promptly if diarrhea becomes severe or persistent.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Calcium channel blockers (e.g., verapamil) | Combining dantrolene with a calcium channel blocker during malignant hyperthermia management is not recommended because of a risk of dangerous cardiovascular collapse. The clinician-authored database describes this as a hyperkalemia mechanism specifically; the FDA label confirms the cardiovascular-collapse danger but frames the risk more broadly (including ventricular fibrillation) without confirming hyperkalemia by name, so the specific hyperkalemia wording is presented as DB-sourced, not independently confirmed by this pass. | (2) (1) |
| CNS depressants (alcohol, benzodiazepines, opioids, sedatives, tranquilizers) | Dantrolene may increase drowsiness when combined with other CNS depressants. | (2) (1) |
| Estrogen | Hepatotoxicity occurs more frequently in women over 35 who are also taking estrogen. Discuss this risk with your prescriber if it applies to you. | (1) |
| Vecuronium (anesthesia/intraoperative context) | Dantrolene may potentiate vecuronium-induced neuromuscular block. This is an intraoperative/anesthesia-context interaction managed by the anesthesia team, not something relevant to routine outpatient use. | (1) |
| Other liver-affecting medications, certain antibiotics, and anti-seizure drugs | The clinician-authored database record notes these as potentially interacting with dantrolene. This specific list was not independently confirmed by the external source reviewed in this pass and is presented as DB-sourced pending further verification. Always inform your healthcare provider of all medications and supplements you are taking. | (2) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
The FDA label states that adequate animal reproduction studies have not been conducted and there is no data on fetal harm; dantrolene should be given during pregnancy only if clearly needed. No specific pregnancy category was established in the sources reviewed. (1)
Breastfeeding
The FDA label states dantrolene should not be used in nursing mothers. (1)
Children
For chronic spasticity in children, the FDA label describes weight-based weekly titration: 0.5 mg/kg once daily for 7 days, then 0.5 mg/kg three times daily for 7 days, then 1 mg/kg three times daily for 7 days, then 2 mg/kg three times daily from week 4 onward, to the same 100 mg four-times-daily maximum as adults. For malignant hyperthermia, the clinician-authored database describes IV dosing similar to adults; this specific pediatric IV figure was not independently confirmed by the oral-capsule label reviewed in this pass. (1)
Renal_impairment
Dantrolene should not be started in people with active liver disease and requires baseline and periodic liver-function testing in everyone because of the boxed hepatotoxicity warning. No specific numeric renal-impairment dose adjustment was established in the sources reviewed. (1)
Hepatic_impairment
Dantrolene should not be started in people with active liver disease and requires baseline and periodic liver-function testing in everyone because of the boxed hepatotoxicity warning. No specific numeric renal-impairment dose adjustment was established in the sources reviewed. (1)
Monitoring
(1)Storage
Store capsules at 20-25°C (68-77°F), protected from moisture and humidity, per the FDA label. The clinician-authored database also notes that reconstituted IV solution should be used promptly as directed by healthcare professionals; this specific IV-handling detail was not established by the oral-capsule label reviewed in this pass and is presented as DB-sourced pending verification against an IV-specific product source.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Chronic spasticity and malignant hyperthermia
Dose summary: Chronic spasticity (adult, oral): week 1, 25 mg once daily; week 2, 25 mg t.i.d.; week 3, 50 mg t.i.d.; week 4+, 100 mg t.i.d. (occasionally q.i.d.); maximum 100 mg four times daily; your prescriber will decide whether to discontinue treatment if there is no benefit after about 45 days. Malignant hyperthermia (oral): preoperative 4-8 mg/kg/day in 3-4 divided doses for 1-2 days before surgery; post-crisis 4-8 mg/kg/day in 4 divided doses for 1-3 days. The DB record's separate IV crisis-treatment figures (2.5 mg/kg initial, up to ~10 mg/kg total) describe emergency in-hospital IV treatment and were not independently confirmed by this oral-capsule label.
Renal context: No specific numeric renal-impairment dose adjustment was established in the sources reviewed. Active hepatic disease is a reason not to start dantrolene, and liver-function monitoring is required in everyone regardless of baseline organ function because of the boxed hepatotoxicity warning. (2) (1)
Frequently asked questions
What is dantrolene used for?
Dantrolene is used to treat muscle spasticity from conditions like cerebral palsy, multiple sclerosis, and spinal cord injury. It is also used before surgery in people known or suspected to be susceptible to malignant hyperthermia, and after a crisis to prevent recurrence.
How does dantrolene work?
Dantrolene works by blocking the release of calcium in muscle cells, which helps relax muscles and reduce spasms.
What are the most serious side effects of dantrolene?
The most serious side effect is liver damage, which can be fatal. Other serious effects include severe muscle weakness, difficulty breathing, and allergic reactions.
Can I drink alcohol while taking dantrolene?
It is best to avoid alcohol while taking dantrolene, as it can increase drowsiness; the clinician-authored database also links alcohol to added liver risk specifically, which was not independently confirmed by the external source reviewed in this pass.
Is dantrolene safe during pregnancy or breastfeeding?
The FDA label states dantrolene should be used during pregnancy only if clearly needed, since adequate reproduction studies have not been conducted, and states it should not be used in nursing mothers. Discuss this with your prescriber before starting or continuing dantrolene if you are pregnant, planning pregnancy, or breastfeeding.
How quickly does dantrolene work for malignant hyperthermia?
The clinician-authored database describes IV dantrolene as acting rapidly, often within minutes, when used for an active malignant hyperthermia crisis; this specific onset-time claim describes emergency in-hospital IV treatment and was not independently confirmed by the oral-capsule label reviewed in this pass.
What should I do if I develop yellowing of the skin or eyes while taking dantrolene?
Contact your healthcare provider immediately, as this may be a sign of the boxed-warning liver-injury risk; let your prescriber assess it and decide whether to continue or stop dantrolene.
What is the mechanism of action of Dantrolene sodium?
Mechanism-of-action detail beyond the recorded indications and dosing above was not captured as a separate field in the clinician-authored database record for this medicine; see how_to_take and professional_information.regional_dosing for the recorded clinical detail. (2)
What is the generic name of Dantrolene Sodium?
The generic name is Dantrolene sodium. It is sold under brand names including Revonto, Dantrolene Link, Dantrium, Dantrolene Sodium, Ryanodex, Dantrol.
What class of drug is Dantrolene sodium?
Dantrolene Sodium is classed as: Skeletal muscle relaxant.
References
- DANTROLENE SODIUM capsule (prescribing information)U.S. Food and Drug Administration (via DailyMed, NIH/NLM) · United States · accessed 2026-08-06 · source 1
- Dantrolene — clinician-authored medicine recordMedGuideGlobal internal clinician-authored medicine record · Global (internal reference) · accessed 2026-08-06 · source 2
- DANTROLENE SODIUM CAPSULE [MAJOR PHARMACEUTICALS] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Dantrolene — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 4
- dantrolene sodium — FDA approval record (Drugs@FDA NDA017443)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 5
- Dantrolene — RxNorm normalized drug concept (RXCUI 3105)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6
Brand names by country
Single-ingredient Dantrolene sodium names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Revonto20 mg/60mL · propharma distribution
- Dantrium20 mg/60mL, 25 mg · par health usa, llc
- RYANODEX dantrolene sodium250 mg/5mL · eagle pharmaceuticals, inc.
Canada
- DANTRIUM
- DANTRIUM INTRAVENOUS