Trade Names:Dantrium- Capsules 25 mg- Capsules 50 mg- Capsules 100 mg
Trade Names:Dantrium Intravenous- Powder for Injection 20 mg/vial (approximately 0.32 mg/mL after reconstitution)
Affects contraction of muscle at site beyond myoneural junction and directly on muscle itself; believed to interfere with calcium release from sarcoplasmic reticulum. Affects CNS, causing drowsiness, dizziness, and generalized weakness.
Absorption is incomplete and slow, but consistent.
Significantly protein bound, mostly albumin.
Metabolized in the liver to the major metabolites 5-hydroxy dantrole and an acetylamino metabolite.
t ½ is 4 to 8 h (IV), 9 h (oral).
Control of spasticity associated with spinal cord injury, stroke, cerebral palsy or multiple sclerosis; prophylaxis, treatment and postcrisis therapy of malignant hyperthermia.
Management of exercise-induced muscle pain, neuroleptic malignant syndrome, heat stroke.
Active hepatic disease; muscle spasm resulting from rheumatic disorders; where spasticity is used to sustain upright posture and balance in locomotion or to obtain or maintain increased function.
PO Initial dose 25 mg every day; increase at 4 to 7 day intervals to 25 mg twice daily to 4 times daily, up to max 100 mg twice daily to 4 times daily if necessary.Children
PO Initial dose 0.5 mg/kg twice daily; increase to 0.5 mg/kg 3 times daily to 4 times daily, then by increments of 0.5 mg/kg, up to 3 mg/kg twice daily to 4 times daily, if necessary. Max 100 mg 4 times daily.Malignant HyperthermiaAdults and Children Preoperative prophylaxis
PO 4 to 8 mg/kg/day in 3 or 4 divided doses for 1 or 2 days prior to surgery with last dose given 3 to 4 h before surgery or IV 2.5 mg/kg approximately 75 min before anesthesia. Infused over 1 h. May repeat during surgery, if needed.Treatment
IV 1 mg/kg by continuous rapid push; evaluate and repeat as needed until cumulative total dose is up to 10 mg/kg.Postcrisis follow-up
PO 4 to 8 mg/kg/day in 4 divided doses for 1 to 3 days to prevent recurrence. If IV route must be utilized, start with at least 1 mg/kg, as needed.
Store at room temperature for up to 6 h. Protect from direct light.
Plasma protein binding of dantrolene reduced.Estrogens
Women receiving these may be at increased risk for hepatotoxicity.Verapamil
Hyperkalemia and myocardial depression possible.Warfarin
Plasma protein binding of dantrolene reduced.
None well documented.
Caused by oral administration except where otherwise indicated.
Tachycardia; erratic BP; phlebitis.
Drowsiness; dizziness; weakness; general malaise; fatigue; speech disturbances; seizures; headache; lightheadedness; insomnia, mental depression or confusion; increased nervousness.
Abnormal hair growth; acne-like rash; pruritus; urticaria (IV); eczematoid eruption; sweating; erythema (IV).
Visual disturbance, diplopia, alteration of taste.
Diarrhea; constipation; bleeding; anorexia; dysphagia; gastric irritation; abdominal cramps.
Increased urinary frequency; hematuria; crystalluria; difficult erection; urinary incontinence; nocturia; dysuria; urinary retention.
Pleural effusion with pericarditis; pulmonary edema (IV).
Myalgia; backache; chills; fever; feeling of suffocation; excessive tearing; thrombophlebitis (IV).
Should not be used in conditions other than those recommended.Hepatotoxicity
The incidence of symptomatic (fatal and nonfatal) hepatitis is lower with doses up to 400 mg/day compared with 800 mg/day or greater. Overt hepatitis was most frequent during the third and twelfth mo but may occur at anytime. Risk is higher in females, patients older than 35 yr of age, and with concurrent therapy. Use only in conjunction with liver monitoring.
Category C (parenteral).
Do not use in nursing women.
Safety in children younger than 5 yr of age not established.
Fatal and nonfatal liver disorders may occur; use drug with caution in patients with preexisting hepatic impairment and in women and patients older than 35 yr of age.
Use drug with caution in patients with impaired pulmonary function (especially COPD) or cardiac function.
Photosensitization may occur.
Because of the high pH of the IV formulation, prevent extravasation into the surrounding tissue.
IV dantrolene is also associated with the loss of grip strength and weakness in the legs.
Safety and efficacy not established; use only if significant pain or disability is present or nursing care is reduced. Consider carcinogenicity risk and liver damage with long-term use. Discontinue therapy if no benefit within 45 days.
Supportive care should be foremost in treatment (ie, concurrent with dantrolene therapy).
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