Dantrium (Dantrolene Sodium) - Side Effects and Adverse Reactions

ADVERSE REACTIONS

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 i.v. dantrolene, which involve patients who could not be weaned from dantrolene after initial treatment.

The administration of intravenous Dantrium 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 i.v. dantrolene possibly contributed.
•  There have been reports of thrombophlebitis following administration of intravenous dantrolene; actual incidence figures are not available. Tissue necrosis secondary to extravasation has been reported.
•  There have been rare reports of urticaria and erythema possibly associated with the administration of i.v. Dantrium. There has been one case of anaphylaxis.
•  Injection site reactions (pain, erythema, swelling), commonly due to extravasation, have been reported.

None of the serious reactions occasionally reported with long-term oral Dantrium use, such as hepatitis, seizures, and pleural effusion with pericarditis, have been reasonably associated with short-term Dantrium Intravenous therapy.

The following events have been reported in patients receiving oral dantrolene: aplastic anemia, leukopenia, lymphocytic lymphoma, and heart failure. (See package insert for Dantrium (dantrolene sodium) Capsules for a complete listing of adverse reactions.)

The published literature has included some reports of Dantrium use in patients with Neuroleptic Malignant Syndrome (NMS). Dantrium Intravenous is not indicated for the treatment of NMS and patients may expire despite treatment with Dantrium Intravenous.

For medical advice about adverse reactions contact your medical professional. To report SUSPECTED ADVERSE REACTIONS, contact JHP at 1-866-923-2547 or MEDWATCH at 1-800-FDA-1088 (1-800-332-1088) or http://www.fda.gov/medwatch/.

REPORTS OF SUSPECTED DANTRIUM SIDE EFFECTS / ADVERSE REACTIONS

Possible Dantrium side effects / adverse reactions in 63 year old male

Reported by a consumer/non-health professional from Japan on 2011-10-28

Patient: 63 year old male

Reactions: Diplopia, Eye Movement Disorder

Suspect drug(s):
Dantrium
    Dosage: 25 mg, bid
    Administration route: Oral
    Indication: Gait Spastic
    Start date: 2010-08-26
    End date: 2011-08-01

Dantrium
    Dosage: unk
    Administration route: Oral
    End date: 2011-08-12

Other drugs received by patient: Methycobal

Possible Dantrium side effects / adverse reactions in 5 year old female

Reported by a physician from Japan on 2011-12-13

Patient: 5 year old female weighing 9.7 kg (21.3 pounds)

Reactions: Apnoea, Somnolence

Adverse event resulted in: life threatening event

Suspect drug(s):
Keppra
    Administration route: Oral

Dantrium
    Administration route: Oral

Keppra
    Administration route: Oral
    Start date: 2011-11-01
    End date: 2011-11-01

Lioresal

Mystan
    Administration route: Oral

Lexotan
    Administration route: Oral

Keppra
    Administration route: Oral
    Indication: Epilepsy
    Start date: 2011-12-01

Phenobarbital TAB
    Administration route: Oral

Haloperidol
    Dosage: 0.5 mg
    Administration route: Oral

Possible Dantrium side effects / adverse reactions in 75 year old female

Reported by a pharmacist from Japan on 2011-12-19

Patient: 75 year old female

Reactions: Hepatitis Fulminant

Adverse event resulted in: death

Suspect drug(s):
Pepcid
    Start date: 2011-03-15
    End date: 2011-03-17

Dantrium
    Indication: Neuroleptic Malignant Syndrome
    Start date: 2011-03-15
    End date: 2011-03-15

Other drugs received by patient: Fentanyl Citrate; Midazolam; Albuminar; Dalteparin Sodium; Cefepime Hydrochloride; Dopamine Hydrochloride