Valproate

Valproate sodium injection is indicated as an intravenous alternative in patients in whom oral administration of valproate products is temporarily not feasible in the following conditions: • Monotherapy and adjunctive therapy of complex partial seizures and simple and complex absence seizures; adjunctive therapy in patients with multiple seizure types that include absence seizures ( 1 ) 1.1 Epilepsy Valproate sodium injection is indicated as an intravenous alternative in patients for whom oral administration of valproate products is temporarily not feasible in the following conditions: Valproate sodium injection is indicated as monotherapy and adjunctive therapy in the treatment of patients …

• Valproate sodium injection is intended for intravenous use only. • Epilepsy o Complex Partial Seizures
• In Adults and Children 10 years of age or older: Initial dose is 10 to 15 mg/kg/day, increasing at 1 week intervals by 5 to 10 mg/kg/day to achieve optimal clinical response
• Maximum recommended dose is 60 mg/kg/day . o Simple and Complex Absence Seizures: Initial dose is 10 to 15 mg/kg/day, increasing at 1 week intervals by 5 to 10 mg/kg/day to achieve optimal clinical response
• Maximum recommended dose is 60 mg/kg/day
• Epilepsy Valproate sodium injection is for intravenous use only
• Use of valproate sodium injection for periods of more than 14 days has not been studied
• Patients should be switched to oral valproate products as soon as it is clinically feasible
• Valproate sodium injection should be administered as a 60 minute infusion (but not more than 20 mg/min) with the same frequency as the oral products, although plasma concentration monitoring and dosage adjustments may be necessary
• In one clinical safety study, approximately 90 patients with epilepsy and with no measurable plasma levels of valproate were given single infusions of valproate sodium injection (up to 15 mg/kg and mean dose of 1,184 mg) over 5 to 10 minutes (1.5 to 3 mg/kg/min)
• Patients generally tolerated the more rapid infusions well [see Adverse Reactions ]
• This study was not designed to assess the effectiveness of these regimens
• For pharmacokinetics with rapid infusions, see Clinical Pharmacology . …

Valproate sodium injection, equivalent to 100 mg of valproic acid per mL, is a clear, colorless solution in 5 mL single-dose vials, available in trays of 10 vials. Recommended storage: Store vials at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Preservative Free. Unused portion of container should be discarded. Injection: 100 mg per mL in a 5 mL single dose vial ( 3 )

• Experience with oral valproate has indicated that pediatric patients under the age of two years are at a considerably increased risk of developing fatal hepatotoxicity, especially those with the aforementioned conditions [see Boxed Warning ]
• The safety of valproate sodium has not been studied in individuals below the age of 2 years
• If a decision is made to use valproate sodium in this age group, it should be used with extreme caution and as a sole agent
• The benefits of therapy should be weighed against the risks. …

No patients above the age of 65 years were enrolled in double-blind prospective clinical trials of mania associated with bipolar illness. In a case review study of 583 patients, 72 patients (12%) were greater than 65 years of age. A higher percentage of patients above 65 years of age reported accidental injury, infection, pain, somnolence, and tremor. Discontinuation of valproate was occasionally associated with the latter two events. …

• Hepatotoxicity Warn patients and guardians that nausea, vomiting, abdominal pain, anorexia, diarrhea, asthenia, and/or jaundice can be symptoms of hepatotoxicity and, therefore, require further medical evaluation promptly [see Warnings and Precautions ]
• Pancreatitis Warn patients and guardians that abdominal pain, nausea, vomiting, and/or anorexia can be symptoms of pancreatitis and, therefore, require further medical evaluation promptly [see Warnings and Precautions ]. …

• Valproate sodium injection should not be administered to patients with hepatic disease or significant hepatic dysfunction [see Warnings and Precautions ( 5.1 )] . • Valproate sodium injection is contraindicated in patients known to have mitochondrial disorders caused by mutations in mitochondrial DNA polymerase γ (POLG; e.g., Alpers-Huttenlocher Syndrome) and children under two years of age who are suspected of having a POLG-related disorder [see Warnings and Precautions ( 5.1 )] . …

• Hepatic enzyme-inducing drugs (e.g., phenytoin, carbamazepine, phenobarbital, primidone, rifampin) can increase valproate clearance, while enzyme inhibitors (e.g., felbamate) can decrease valproate clearance. Therefore increased monitoring of valproate and concomitant drug concentrations and dosage adjustment are indicated whenever enzyme-inducing or inhibiting drugs are introduced or withdrawn ( 7.1 ) • Aspirin, carbapenem antibiotics, estrogen-containing hormonal contraceptives: Monitoring of valproate concentrations is recommended ( 7.1 ) • Co-administration of valproate can affect the pharmacokinetics of other drugs (e.g. …

• Hepatotoxicity; evaluate high risk populations and monitor serum liver tests ( 5.1 ) • Birth defects, decreased IQ, and neurodevelopmental disorders following in utero exposure; should not be used to treat women with epilepsy or bipolar disorder who are pregnant or who plan to become pregnant or to treat a woman of childbearing potential unless other medications have failed to provide adequate symptom control or are otherwise unacceptable ( 5.2 , 5.3 , 5.4 ) • Pancreatitis; valproate sodium should ordinarily be discontinued ( 5.5 ) • Bleeding and other hematopoietic disorders; monitor platelet counts and coagulation tests ( 5.7 ) • Hyperammonemia and hyperammonemic encephalopathy; measure …

The following serious adverse reactions are described below and elsewhere in the labeling: • Hepatic failure [see Warnings and Precautions ( 5.1 )] • Birth defects [see Warnings and Precautions ( 5.2 )] • Decreased IQ following in utero exposure [see Warnings and Precautions ( 5.3 )] • Pancreatitis [see Warnings and Precautions ( 5.5 )] • Hyperammonemic encephalopathy [see Warnings and Precautions ( 5.6 , 5.8 , 5.9 )] • Bleeding and other hematopoietic disorders [see Warnings and Precautions ( 5.7 )] • Hypothermia [see Warnings and Precautions ( 5.10 )] • Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan hypersensitivity reactions [see Warnings and Precautions ( 5.11 ) …

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to antiepileptic drugs (AEDs), including Valproate sodium, during pregnancy. Encourage women who are taking Valproate sodium during pregnancy to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry by calling toll-free 1-888-233-2334 or visiting the website, http://www.aedpregnancyregistry.org/. …

Overdosage with valproate may result in somnolence, heart block, deep coma, and hypernatremia. Fatalities have been reported; however patients have recovered from valproate serum concentrations as high as 2,120 mcg/mL. In overdose situations, the fraction of drug not bound to protein is high and hemodialysis or tandem hemodialysis plus hemoperfusion may result in significant removal of drug. General supportive measures should be applied with particular attention to the maintenance of adequate urinary output. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.