Phenytoin Dosing Calculator & Analysis
Phenytoin is a widely used anticonvulsant medication for the treatment and prevention of seizures. Accurately calculating phenytoin dosing is crucial to ensure therapeutic effectiveness and minimize adverse effects. This calculator simplifies the process, providing instant results and analysis.
- Enter the patient’s weight in kilograms.
- Enter the desired dosage in milligrams per kilogram.
- Select the administration frequency.
- Click ‘Calculate’.
The calculator uses the following formula to determine the total daily dose:
Total Daily Dose (mg) = Weight (kg) × Dosage (mg/kg) × Frequency (hours)
The maintenance dose is then calculated as:
Maintenance Dose (mg) = Total Daily Dose / Frequency (hours)
| Weight (kg) | Dosage (mg/kg) | Frequency (hours) | Total Daily Dose (mg) | Maintenance Dose (mg) |
|---|
| Drug | Interaction |
|---|
- Always monitor phenytoin levels to ensure therapeutic effectiveness and minimize toxicity.
- Be aware of drug interactions that can affect phenytoin metabolism.
- Consider using extended-release phenytoin formulations to improve adherence and reduce side effects.
What is the therapeutic range for phenytoin?
The therapeutic range for phenytoin is typically 10-20 mg/L (free drug) or 15-40 mg/L (total drug).
How is phenytoin metabolism affected by genetics?
Phenytoin is metabolized primarily by the CYP2C9 and CYP2C19 enzymes. Genetic variations in these enzymes can affect phenytoin metabolism and clearance.