Key points
- We recommend to consult your poison centre with the use of this antidote.
- The only known indication for dantrolene is the treatment of malignant hyperthermia (pathology of striated muscle), since it is not a centrally acting drug.
- Each vial of intravenous dantrolene contains 3 g of mannitol.
+ Synonyms and other terms
- Dantrium™
+ Indications
- Malignant hyperthermia
+ Dosage
+ Pediatric Dose
- Initially: 2,5 mg/kg by direct IV; can be repeated at 1 to 2,5 mg/kg every 5 to 10 min, until rigidity has subsided.
- Maximum cumulative dose according to manufacturer's monograph is 10 mg/kg.
- However, higher dose can be required for patient with persistent contractures and rigidity, when malignant hyperthermia is still considered the likely diagnosis.
- Maintenance dose: 1 to 2 mg/kg by direct IV every 6 h for 1 to 3 days.
+ Adult Dose
- Initially: 2,5 mg/kg by direct IV; can be repeated at 1 to 2,5 mg/kg every 5 to 10 min, until rigidity has subsided.
- Maximum cumulative dose according to manufacturer's monograph is 10 mg/kg.
- However, higher dose can be required for patient with persistent contractures and rigidity, when malignant hyperthermia is still considered the likely diagnosis.
- Maintenance dose: 1 to 2 mg/kg by direct IV every 6 h for 1 to 3 days.
+ Renal Impairment
No data suggests that the dose should be modified for short-term use.
+ Hepatic Impairment
No data suggests that the dose should be modified for short-term use.
+ Hemodialysis Patient
No data suggests that the dose should be modified for short-term use.
+ Obese or Overweight Patient
No data suggests that the dose should be modified for short-term use.
+ Adverse effects
- With short term use: generalized weakness, drowsiness, dizziness, diarrhea, nausea and phlebitis near the infusion site. More serious adverse effects include anaphylaxis, ARDS and hyperkalemia.
+ Monitoring
- Glasgow Coma Scale
- Transaminases
- CBC
- Signs of phlebitis at the infusion site.
+ End of treatment
- No evidence of muscular hypermetabolism (i.e., decreased creatine kinase and myoglobinuria) for 1 to 3 days.
+ Special Notes on Administration
Intravenous Route (IV)
- Direct IV
- Administer diluted to a final concentration of 0.33mg/ml at a maximum rate of 1 mg/kg/min.
- Small doses can be supplemented with SWFI to facilitate administration.
- Because of the high pH (9.5) of the intravenous formulation there is potential for tissue necrosis. Care must be taken to prevent extravasation.
Intraosseous Route (IO)
- No data available.
Subcutaneous Route (SC)
- Not a recommended route.
Intramuscular Route (IM)
- Not a recommended route.
Enteral Route (PO or NG Tube)
- Not a recommended route for malignant hyperthermia treatment
Reconstitution
- Reconstitute each 20 mg vial with 60 ml of SWFI without bacteriostatic agent. Final volume = 61 ml. Final concentration = 0.33 mg/ml.
- Shake vial until solution is clear.
- Protect the content of the vial from light.
- Use within six hours of reconstitution.
Compatibility
Partial list only. Consult the pharmacist on duty at your health care facility.
- Compatible solutions: SWFI without bacteriostatic agent.
- Incompatible solutions NS, D5W, bacteriostatic SWFI
- Y-site compatibility: No data
- Y-site incompatibility: No data
Stability
- Unreconstituted vials must be stored at a controlled room temperature (between 20 and 25ºC) away from light.
- Vials reconstituted with SWFI are stable for 6 hours when stored at 15 to 30 degrees C and protected from light.
+ Available products
- Dantrium intravenous, 20 mg/vial, Pd. Inj. IV, DIN 01997572, PAR Pharmaceuticals Companies, distributed by Methapharm Inc, (Also contains 3 mg of mannitol per vial).
+ Amount required to treat a person weighting 70kg during 24 hours
- At least 700 mg of injectable dantrolene.
+ References
Benson, Blaine E. 2016. “Dantrolene.” In Critical Care Toxicology, edited by Jeffrey Brent, Keith Burkhart, Paul Dargan, Benjamin Hatten, Bruno Megarbane, and Robert Palmer, 1–14. Cham: Springer International Publishing.
Pileggi, Dominic J., and Aaron M. Cook. 2016. “Neuroleptic Malignant Syndrome.” The Annals of Pharmacotherapy 50 (11):973–81.
Rosenberg, Henry, Neil Pollock, Anja Schiemann, Terasa Bulger, and Kathryn Stowell. 2015. “Malignant Hyperthermia: A Review.” Orphanet Journal of Rare Diseases 10 (August):93.
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