治療癲癇 Absence seizure, Simple and complex; Complex partial epileptic seizure
藥理
Anticonvulsants
Valproate sodium is an antiepileptic agent with unknown therapeutic mechanism of action, although, it is believed to exert its effect by increasing the concentrations of gamma-aminobutyric acid (GABA) in the brain.
藥動學
Distribution
1. Vd: 11 L/1.73 m2
2. Protein binding: approximately 10% unbound at 40 mcg/mL and 18.5% unbound at 130 mcg/mL, concentration dependent Metabolism
Hepatic; glucuronosyltransferase; over 40% by mitochondrial beta-oxidation, glucuronidation Excretion
1. Renal: 30% to 50% as glucuronide conjugate, less than 3% unchanged 2. Dialyzable: yes (hemodialysis), about 20% Elimination Half Life
1. 16 h +/- 3 h
2. Children (greater than 2 mo): 7 h to 13 h
3. Neonates (less than 10 days): 10 h to 67 h
4. Liver impairment: increased from 12 h to 18 h
禁忌症
1. Hepatic disease or significant hepatic dysfunction
2. Hypersensitivity to valproate sodium
3. Use in patients with mitochondrial disorders caused by mutations in mitochondrial DNA polymerase gamma (POLG; eg, Alpers-Huttenlocher syndrome) and in children younger than 2 years with a suspected POLG-related disorder
4. For prevention of migraine headaches in pregnant women
5. Urea cycle disorders
懷孕分類
X (FDA) D (AUS)
哺乳分類
Infant risk cannot be ruled out
副作用
Common:
Dermatologic: Injection site pain (2.6% ), Injection site reaction (2.4% )
Gastrointestinal: Nausea (3.2% )
Neurologic: Dizziness (5.2% to 7.1% ), Headache (2.7% to 4.3% ), Somnolence (1.7% to 10.7% ) Serious:
Endocrine metabolic: Hyperammonemia
Gastrointestinal: Pancreatitis
Hematologic: Myelodysplastic syndrome, Thrombocytopenia (27% )
Hepatic: Liver failure
Immunologic: Drug reaction with eosinophilia and systemic symptoms
Neurologic: Hyperammonemic encephalopathy
劑量和給藥方法
1. Initial: 10-15mg/kg/day, increased by 5-10mg/kg daily at one week intervals until seizures are controlled
2. Maximum recommended dosage: 60mg/kg/day
小兒調整劑量
Seizures disorders: (Not recommended for ages <6 years)
1. Initial: 10-15mg/kg/day in 1 to 3 divided doses, increased by 5-10mg/kg daily at one week intervals until seizures are controlled
2. Maintenance: 30 to 60 mg/kg/day in 2 to 3 divided doses Migraine prophylaxis: (Limited data available, for Children ≥12 years and Adolescents)
Initial 500 mg once daily for 15 days, may increase to 1,000 mg once dailiy; dose should be individualized
腎功能調整劑量
Mild to severe impairment: No dosage adjustment required (including patients on hemodialysis); however, protein binding is reduced in patients with renal impairment; monitoring only total valproate serum concentrations may be misleading
肝功能調整劑量
1. Mild to moderate impairment: Not recommended for use in hepatic disease; clearance is decreased with liver impairment.
2. Severe impairment: Use is contraindicated