About This Tool
This Fintepla Dosing Calculator provides a suggested dosing schedule based on patient parameters according to the Prescribing Information. It is intended for healthcare professionals as an educational and informational resource. This content provides supplementary context for the calculator's inputs and outputs but does not replace the need for clinical judgment and adherence to the official FDA-approved labeling.
Outputs Explained
After entering the required patient information into the calculator, it will generate a detailed dosing schedule, which includes:
- Titration Schedule: Provides step-by-step weekly dose recommendations for the initial and titration phases of treatment, where applicable.
- Maintenance Dose: Calculates the final recommended maintenance dose after the titration period is complete.
- Volume per Dose (mL): Translates each calculated milligram (mg) dose into a measurable volume in milliliters (mL), based on the Fintepla oral solution concentration of 2.2 mg/mL.
- Total Daily Dose (mg/day): Summarizes the total amount of medication administered per day for each phase of treatment.
- Dosing Considerations: Displays important context, such as the maximum daily dose and notes related to concomitant medications or patient-specific factors like renal or hepatic impairment.
How to Use the Calculator
Follow these steps to generate a dosing regimen:
- Select Indication: Choose either Dravet Syndrome (DS) or Lennox-Gastaut Syndrome (LGS) from the dropdown menu.
- Enter Patient Weight: Input the patient's current weight. You can toggle between kilograms (kg) and pounds (lbs). The tool will automatically convert the value to kg for its calculations.
- Specify Concomitant Medications: Check the box if the patient is also taking stiripentol plus clobazam, as this significantly alters the recommended Fintepla dosage.
- Indicate Impairment: Select any relevant renal or hepatic impairment status to view corresponding dosing adjustments and recommendations from the Prescribing Information.
- Review Results: The calculator will automatically display the full dosing schedule and relevant clinical notes based on your inputs. No "calculate" button is needed.
Dosing Overview
Fintepla (fenfluramine) dosing is initiated at a low dose and gradually titrated upwards to the target maintenance dose. The specific regimen depends on whether the patient is also taking stiripentol and clobazam.
| Phase | Standard Therapy | With Stiripentol + Clobazam |
|---|---|---|
| Initial Dose | 0.2 mg/kg/day, divided into two doses | 0.2 mg/kg/day, divided into two doses |
| Titration Step | Increase to 0.35 mg/kg/day after 1 week | Increase to 0.35 mg/kg/day after 1 week |
| Maintenance Dose | Increase to 0.7 mg/kg/day after another week | Maintain at 0.35 mg/kg/day |
| Maximum Daily Dose | 26 mg/day | 17 mg/day |
All calculations are based on the Fintepla oral solution concentration of 2.2 mg/mL. The total daily dosage is administered as two equal, separate doses.
Switching Medications
There is no specific guidance on switching from other anti-seizure medications to Fintepla. The initiation of Fintepla, or any changes to a patient's anti-seizure regimen, should be managed by a healthcare professional experienced in treating epilepsy. Abrupt discontinuation of any anti-seizure medication, including Fintepla, may increase seizure frequency or precipitate status epilepticus.
Missed Dose
If a dose of Fintepla is missed, the caregiver should administer the dose as soon as they remember. If it is almost time for the next scheduled dose, the missed dose should be skipped. The next dose should be taken at the regularly scheduled time. Caregivers should not administer a double dose to make up for a missed one.
Safety Alerts
BOXED WARNING: VALVULAR HEART DISEASE (VHD) and PULMONARY ARTERIAL HYPERTENSION (PAH).
Fintepla can cause VHD and PAH. Echocardiogram assessments are required before treatment, every 6 months during treatment, and 3 to 6 months after treatment discontinuation. If signs of VHD, intracardiac shunt, or PAH are present, a cardiologist must be consulted to weigh the risks and benefits of starting or continuing treatment.
Other significant safety considerations include decreased appetite and weight loss, somnolence, sedation, lethargy, and an increased risk of suicidal behavior and ideation. Always refer to the full Prescribing Information for a complete list of warnings and precautions.
Frequently Asked Questions (FAQ)
Why is the concomitant use of stiripentol and clobazam a critical input?
Stiripentol is a strong CYP2C19 and CYP3A4 inhibitor, which significantly increases the concentration of fenfluramine in the body. To avoid potential toxicity, the maximum recommended dosage of Fintepla is substantially lower for patients taking stiripentol.
How does the calculator handle kg vs. lbs for patient weight?
The calculator allows you to enter weight in either unit. However, all internal calculations are performed using kilograms (kg), as this is the standard unit for weight-based dosing in the Prescribing Information. It automatically converts lbs to kg using the standard conversion factor (1 kg ≈ 2.20462 lbs).
What happens if the calculated dose exceeds the absolute maximum daily dose?
The calculator logic caps the total daily dose at the FDA-recommended maximum (26 mg/day for standard therapy or 17 mg/day with stiripentol), even if the patient's weight-based calculation (mg/kg/day) results in a higher number. This prevents recommending a dose that exceeds established safety limits.
What is the concentration of the oral solution used in calculations?
All volume (mL) calculations are based on the Fintepla oral solution concentration of 2.2 mg/mL, which is the commercially available formulation.
What guidance does the calculator provide for patients with renal or hepatic impairment?
When an impairment option is selected, the tool provides an informational note highlighting that a lower maintenance dosage may be required (e.g., maximum of 0.35 mg/kg/day, not to exceed 17 mg/day) and that Fintepla is not recommended in severe hepatic impairment, directing the user to the Prescribing Information for full details.
Why does the calculator have a weight range warning?
The calculator may issue a warning if the entered weight is outside a typical clinical range (e.g., <7 kg or >150 kg). This serves as a safety check to prompt the user to double-check their input for typos and to ensure the dose is for an appropriate patient, as clinical trial data may be limited outside these ranges.
Can this calculator be used for any other conditions?
No. This tool is specifically designed for the FDA-approved indications of Dravet Syndrome and Lennox-Gastaut Syndrome in patients meeting the age and weight criteria specified in the Prescribing Information.
Is this calculator a substitute for the official Prescribing Information?
Absolutely not. The calculator is an informational aid. It is not a substitute for clinical judgment or the official, most current FDA-approved Fintepla Prescribing Information, which must always be consulted as the primary source of truth for dosing and administration.
References
- FINTEPLA® (fenfluramine) oral solution Prescribing Information. UCB, Inc. Revised: 03/2022.
- Fintepla Dosing and Administration. UCB, Inc. Accessed October 2023.
- Fintepla Professional Information. Drugs.com. Accessed October 2023.
- Fintepla (fenfluramine) European Public Assessment Report (EPAR). European Medicines Agency.
