FOR SPASTICITY: THE INITIAL DOSE IS 25 MG DAILY BY MOUTH INCREASED GRADUALLY AS NECESSARY, AT 7-DAY INTERVALS, OVER ABOUT 7 WEEKS TO A MAXIMUM DOSE OF 100 MG FOUR TIMES DAILY. IF NO RESPONSE IS ACHIEVED WITHIN 45 DAYS, TREATMENT SHOULD BE STOPPED.
IN CHILDREN, US LICENSED PRODUCT INFORMATION SUGGESTS A DOSE OF 0.5 MG/KG ONCE DAILY, INCREASED GRADUALLY IF NECESSARY TO 2 MG/KG THREE TIMES DAILY; DOSAGE FOUR TIMES DAILY MAY BE NECESSARY FOR SOME CHILDREN BUT A DOSE OF 100 MG FOUR TIMES DAILY SHOULD NOT BE EXCEEDED.
MALIGNANT HYPERTHERMIA : DANTROLENE SODIUM IS GIVEN, WITH SUPPORTIVE MEASURES, IN AN INITIAL DOSE OF 1 MG/KG BY RAPID INTRAVENOUS INJECTION, REPEATED, IF NECESSARY, TO A TOTAL DOSE OF 10 MG/KG. AN AVERAGE DOSE OF 2.5 MG/KG IS USUALLY EFFECTIVE.
IF A RELAPSE OR RECURRENCE OCCURS, DANTROLENE SHOULD BE GIVEN AGAIN AT THE LAST EFFECTIVE DOSE. IN THE USA, DOSES OF 1 TO 2 MG/KG BY MOUTH FOUR TIMES DAILY HAVE BEEN RECOMMENDED FOR UP TO 3 DAYS AFTER THE CRISIS TO PREVENT RECURRENCE, AND SIMILAR DOSES HAVE BEEN GIVEN FOR 1 TO 2 DAYS BEFORE SURGERY IN INDIVIDUALS THOUGHT TO BE AT RISK OF DEVELOPING THE SYNDROME.
PROPHYLACTIC DOSES MAY ALSO BE GIVEN INTRAVENOUSLY; 2.5 MG/KG HAS BEEN RECOMMENDED, INFUSED OVER ABOUT 60 MINUTES, STARTING ABOUT 75 MINUTES BEFORE ANTICIPATED ANAESTHESIA, WITH FURTHER DOSES DURING ANAESTHESIA AND SURGERY IF SIGNS OF MALIGNANT HYPERTHERMIA DEVELOP.