Dose Inputs
Example Data Table
| Age | Sex | Height (cm) | Weight (kg) | SCr (mg/dL) | BSA (Mosteller) | CrCl (CG) | Protocol | Final dose (mg) |
|---|---|---|---|---|---|---|---|---|
| 52 | Male | 175 | 78 | 1.0 | 1.96 | 92 | 750 mg/m² | 1470 |
| 68 | Female | 160 | 62 | 1.4 | 1.63 | 41 | 750 mg/m² + renal | 920 |
| 34 | Male | 182 | 110 | 0.9 | 2.30 (cap 2.0) | 149 | 1000 mg/m² + cap | 2000 |
Formula Used
- Mosteller: BSA = √(height_cm × weight_kg / 3600)
- DuBois: BSA = 0.007184 × height_cm^0.725 × weight_kg^0.425
- IBW: Male 50 + 0.9 × (cm − 152), Female 45.5 + 0.9 × (cm − 152)
- AdjBW: IBW + 0.4 × (Actual − IBW) when Actual > IBW
- BSA-based: Base = (mg/m²) × BSA_used
- Weight-based: Base = (mg/kg) × weight_for_dose
- Final dose: Final = Base × renal_factor × hepatic_factor × other_factor
- Rounding: Rounded = round(Final / increment) × increment
- Per-day: PerDay = Rounded / days (then rounded)
How to Use This Calculator
- Enter age, sex, height, weight, creatinine, and bilirubin.
- Select a dose basis and type the protocol dose value.
- Choose BSA formula and optional BSA cap if required.
- Pick weight choices for CrCl and mg/kg dosing.
- Set renal and hepatic modes, then add optional reductions.
- Choose schedule days and rounding, then calculate.
- Review results, notes, and formulas; then export if needed.
What this calculator estimates
This tool estimates a cyclophosphamide dose from a protocol value entered as either mg/m² or mg/kg. It computes a base dose, optionally caps the dosing BSA, and then applies renal, hepatic, and other modifiers. The output includes total dose, grams, and a simple per-day split for 1–5 day schedules. Results are intended for planning and documentation, not automatic prescribing.
Inputs and derived values
Height and weight are used to calculate body surface area using either Mosteller (√(height_cm × weight_kg / 3600)) or the DuBois method. Ideal body weight and adjusted body weight are shown to support weight selection choices. Renal function is estimated with Cockcroft–Gault creatinine clearance using age, sex, serum creatinine, and a selectable weight basis (actual, ideal, or adjusted).
Dosing pathways and modifiers
For BSA-based dosing, Base = (mg/m²) × BSA_used; for weight-based dosing, Base = (mg/kg) × weight_for_dose. Renal and hepatic adjustments can be applied automatically or as custom factors between 0.05 and 1.00. The auto renal scale uses CrCl cutoffs of ≥60, 30–59, 10–29, and <10 mL/min to apply 1.00, 0.75, 0.50, and 0.25. The auto hepatic scale uses bilirubin ≤1.5, 1.6–3.0, and >3.0 mg/dL to apply 1.00, 0.75, and 0.50. Optional reductions include a prior severe toxicity toggle (example 0.75 multiplier) and a manual percent reduction.
Rounding, schedules, and exports
Total dose is rounded to the nearest selected increment (1, 5, 10, 25, or 50 mg), then divided across the chosen schedule, with the per-day value rounded again to match ordering workflows. CSV and PDF exports capture the key inputs, derived values, multipliers, and final dose so calculations can be reviewed. The most recent result is stored in-session to support immediate downloads without re-entry. When rounding, consider vial sizes, dose banding, and infusion concentrations per policy. Exports help reviewers confirm assumptions quickly before administration.
Quality checks and documentation
Before using the estimate, verify the protocol dose unit, dosing basis, and any institutional rules for BSA caps and weight selection. Confirm labs reflect current clinical status and that renal/hepatic adjustment logic matches the regimen. Document the chosen formula, all multipliers, rounding increment, schedule days, and clinical rationale. Recalculate whenever weight, creatinine, bilirubin, or protocol intent changes.
FAQs
1) Which BSA formula should I select?
Use the method required by your protocol. Mosteller is common for routine dosing; DuBois may appear in older references. Keep the same formula across cycles to avoid unintended variability.
2) Why would I cap BSA?
Some regimens cap BSA to reduce extreme doses in larger patients. If your protocol specifies a cap, enable it and enter the cap value; otherwise leave capping off.
3) Which weight should be used for Cockcroft–Gault?
Institutions differ. This calculator lets you choose actual, ideal, or adjusted weight for the creatinine clearance estimate. Use your local policy, especially in obesity or underweight patients.
4) What do renal and hepatic factors represent?
They are dose multipliers applied to the base dose. Auto mode uses example cutoff tables for CrCl and bilirubin, while custom mode lets you enter a factor defined by your protocol.
5) How is the per-day dose calculated?
The tool rounds the total dose to your chosen increment, divides by the number of schedule days, then rounds the per-day value again. Review day-to-day totals if your regimen requires exact summation.
6) Can I use this for pediatric dosing?
It can compute BSA and dose math, but pediatric protocols often add age-specific adjustments and caps. Use only with pediatric-specific guidance and pharmacist or specialist review.