For a loading dose (2.5 mg/kg)1,3
Patient’s weight in kg Patient’s weight in pounds Number of 250 mg vials to open mg dosage needed mL of reconstituted RYANODEX® (dantrolene sodium) for injectable suspension to administer
5 11 1 12.5 mg 0.25 mL
10 22 1 25.0 mg 0.50 mL
15 33 1 37.5 mg 0.75 mL
20 44 1 50.0 mg 1.00 mL
25 55 1 62.5 mg 1.25 mL
30 66 1 75.0 mg 1.50 mL
35 77 1 87.5 mg 1.75 mL
40 88 1 100.0 mg 2.00 mL
45 99 1 112.5 mg 2.25 mL
50 110 1 125.0 mg 2.50 mL
55 121 1 137.5 mg 2.75 mL
60 132 1 150.0 mg 3.00 mL
65 143 1 162.5 mg 3.25 mL
70 154 1 175.0 mg 3.50 mL
75 165 1 187.5 mg 3.75 mL
80 176 1 200.0 mg 4.00 mL
85 187 1 212.5 mg 4.25 mL
90 198 1 225.0 mg 4.50 mL
95 209 1 237.5 mg 4.75 mL
100 220 1 250.0 mg 5.00 mL
105 231 2 262.5 mg 5.25 mL
110 242 2 275.0 mg 5.50 mL
115 253 2 287.5 mg 5.75 mL
120 264 2 300.0 mg 6.00 mL
125 275 2 312.5 mg 6.25 mL
130 286 2 325.0 mg 6.50 mL
135 297 2 337.5 mg 6.75 mL
140 308 2 350.0 mg 7.00 mL
145 319 2 362.5 mg 7.25 mL
150 330 2 375.0 mg 7.50 mL

Labeled dose range of 1 to 10 mg/kg with a maximum cumulative dose of 10 mg/kg.

As soon as the MH reaction is recognized, all volatile anesthetics and succinylcholine should be discontinued; ventilation with high concentration oxygen is recommended. Anesthesia may be maintained with non-triggering agents. RYANODEX® (dantrolene sodium) for injectable suspension should be administered by intravenous push beginning at a recommended loading dose of 2.5 mg/kg.1,3

RYANODEX® can be administered either into the intravenous catheter while an intravenous infusion of 0.9% sodium chloride injection, or 5% dextrose injection is freely running; or into the indwelling catheter–after assuring its patency–without a freely running infusion. Flush the line to assure that there is no residual RYANODEX® remaining in the catheter.

In addition to RYANODEX® treatment, institute the following supportive measures:

  • Discontinue use of malignant hyperthermia (MH)-triggering anesthetic agents (eg, volatile anesthetic gases and succinylcholine).
  • Manage the metabolic acidosis
  • Institute cooling when necessary

Administer diuretics to prevent late kidney injury due to myoglobinuria (the amount of mannitol in RYANODEX® is insufficient to maintain diuresis)

Administer RYANODEX® by intravenous push at a minimum dose of 1 mg/kg. If the physiologic and metabolic abnormalities of MH continue, administer additional intravenous boluses up to the maximum cumulative dosage of 10 mg/kg.

If the physiologic and metabolic abnormalities of MH continue, administer additional intravenous boluses up to the maximum cumulative dosage of 10 mg/kg. If the physiologic and metabolic abnormalities reappear, repeat RYANODEX® dosing by intravenous push starting with 1 mg/kg.

Pediatric dose

The recommended weight-based dose of RYANODEX® for pediatric patients in the treatment and prevention of MH is the same as for adults for these indications.1

Dosage for Prevention of Malignant Hyperthermia

The recommended prophylactic dose of RYANODEX® is 2.5 mg/kg administered intravenously over a period of at least 1 minute, starting approximately 75 minutes prior to surgery. Avoid agents that trigger MH.1

Inconsequential amount of mannitol

Each vial of RYANODEX® contains 125 mg of mannitol compared to 3000 mg of mannitol in each vial of other dantrolene sodium for injection products. When mannitol is used in the prevention or treatment of late renal complications of malignant hyperthermia, the high concentration of mannitol in other dantrolene sodium for injection products should be taken into consideration. RYANODEX® does not contain a sufficient amount of mannitol to induce and maintain a level of diuresis that may be required.1,9,10