Phenytoin Free Fraction Renal Calculator
Actual independently measured free/total phenytoin fraction under matched assay/state, not albumin corrected proxy or estimate from renal functional one. All patient/product/route/units and applicable inputs independently clinically established; no dose, route, frequency, eligibility, titration, diagnosis or permission to administer is supplied.
Description
An unbound phenytoin fraction compares separately measured free and total concentrations on the same basis.
An unbound phenytoin fraction compares separately measured free and total concentrations on the same basis.1
This tool calculates that fraction; it does not estimate renal effects or infer an unmeasured free concentration.
When to use Phenytoin Free Fraction Renal Calculator
This tool calculates that fraction; it does not estimate renal effects or infer an unmeasured free concentration.
How to use Phenytoin Free Fraction Renal Calculator and how it works
- Prepare measured unbound phenytoin concentration, measured total phenytoin concentration, using the input definitions and matching units below.
- Enter the required fields and run Phenytoin Free Fraction Renal Calculator.
- Read result.value using the units, signs and ordering explained below.
- Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| actualMeasuredUnboundPhenytoinConcentration | Actual Measured Unbound Phenytoin Concentration. Use the units and matching context stated in the calculation below. | number | Required; nonnegative; finite; other constraints below |
| actualMeasuredTotalPhenytoinConcentration | Actual Measured Total Phenytoin Concentration. Use the units and matching context stated in the calculation below. | number | Required; strictly positive; finite; other constraints below |
Require nonnegative measured unbound concentration and positive measured total concentration in matching units, with unbound not exceeding total. Return unbound divided by total as a dimensionless fraction, not a percentage. No renal coefficient or inferred free concentration is calculated.
freeFraction=measuredUnbound/measuredTotal Apply the input ordering, units and branch conditions stated above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Object containing the calculated or selected fields below. | object |
| result.value | Numeric model result on the ratio, score, constant or density basis explained above. | number |
{
"input": {
"actualMeasuredUnboundPhenytoinConcentration": 1,
"actualMeasuredTotalPhenytoinConcentration": 10
},
"output": {
"result": {
"value": 0.1
}
}
}Limitations and assumptions
Patient context, drug formulation, route, sampling time, assay units and applicable clinician-verified protocol must be independently established. The output supplies no dosing, titration, switching or administration instruction.
The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.
All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.
Alternative or Complementary methods
Use Phenytoin Albumin Correction Calculator for a complementary operation: Albumin-related phenytoin interpretation requires a specified model and patient context.
Use Theophylline Level Checker for a complementary operation: A theophylline concentration needs an assay unit, sampling time and applicable clinical context before comparison with a review range.
References
-
Phenytoin Free Fraction Renal Calculator — tool.io
Similar or alternative tools
- Phenytoin Albumin Correction Calculator
Albumin-related phenytoin interpretation requires a specified model and patient context.
- Theophylline Level Checker
A theophylline concentration needs an assay unit, sampling time and applicable clinical context before comparison with a review range.