From the FDA Drug Label
For adults and children 10 years of age or older. Monotherapy (Initial Therapy): Valproic acid has not been systematically studied as initial therapy. Patients should initiate therapy at 10 to 15 mg/kg/day. The dosage should be increased by 5 to 10 mg/kg/week to achieve optimal clinical response Ordinarily, optimal clinical response is achieved at daily doses below 60 mg/kg/day.
The patient weighs 100 kg (219 lbs).
- The starting dose is 10 to 15 mg/kg/day.
- For a 100 kg patient, the dose would be 1000 to 1500 mg/day.
- The dosage should be increased by 5 to 10 mg/kg/week to achieve optimal clinical response, with ordinary optimal response at daily doses below 60 mg/kg/day 1
From the Research
For a patient weighing 100 kg with seizures, the recommended starting dose of Depakote (valproate) would be 1000-1500 mg per day, typically divided into two or three doses. This is based on the standard initial dosing of 10-15 mg/kg/day for adults with epilepsy 2. The medication should be started at this lower dose and then gradually increased every few days as needed to achieve seizure control, with close monitoring for side effects. Some key points to consider when initiating Depakote therapy include:
- The maximum recommended daily dose is generally 60 mg/kg/day, though most patients achieve seizure control at lower doses.
- Depakote works by increasing levels of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter in the brain, and by blocking voltage-sensitive sodium channels, which helps prevent the abnormal electrical activity that causes seizures.
- Common side effects include gastrointestinal disturbances, sedation, and tremor.
- Regular monitoring of blood levels, liver function, and complete blood counts is necessary during treatment.
- The therapeutic serum concentration range for seizure control is typically 50-100 μg/mL. It's also important to note that once-daily dosing is appropriate for extended-release divalproex over a wide dose range, but not for enteric-coated, delayed-release divalproex, as it may produce high maximum VPA concentrations and clinical toxicity 2. In terms of specific dosing, a study found that only the 1125 mg once-daily divalproex dose had mean C(max) < 100 mg/L, while higher doses produced mean C(max) > 125 mg/L 2. Overall, the key is to start with a lower dose and gradually increase as needed, while closely monitoring for side effects and adjusting the dose accordingly.