Irinotecan Dose Tool Calculator

Example Data Table

Formula Used

• Mosteller BSA: BSA (m²) = √[(Height(cm) × Weight(kg)) / 3600]
• Dose: Dose (mg) = BSA (m²) × Target dose (mg/m²)
• Optional reduction: Dose × (1 − reduction%/100)
• Optional rounding: Round to nearest chosen mg increment
• Volume estimate: Volume (mL) = Rounded dose (mg) ÷ Concentrate (mg/mL)
• Bag estimate: Bag volume (mL) = Rounded dose (mg) ÷ Target final concentration (mg/mL)

How to Use This Calculator

1. Enter height and weight to compute BSA.
2. Select the regimen schedule used by your protocol.
3. Use custom mg/m² only when protocol is verified.
4. Apply reductions and caps only when indicated clinically.
5. Review safety prompts and ensure toxicities resolved.
6. Press Calculate Dose to display results above.
7. Export CSV or PDF for documentation, then verify orders.

Body surface area drives dose scaling

Most irinotecan regimens are prescribed as mg per square meter. This calculator uses the Mosteller method to estimate BSA from height and weight, then multiplies by the selected target mg/m². For example, a BSA of 1.80 m² at 180 mg/m² gives 324 mg before rounding. Because BSA changes with weight fluctuations, re-check inputs each cycle and document the measurement date.

Reference schedules and protocol alignment

The schedule selector provides common reference patterns such as every-two-week dosing and every-three-week single-agent dosing. These values are included to speed workflow, not to define care. Your local protocol may specify different starting doses, maximum doses, infusion times, or combination partners. Use the custom mg/m² option only when you have a verified regimen order set and a prescriber-approved target dose. Consider renal function, performance status, and supportive care plans when selecting and validating the intended dose today.

Rounding and preparation estimates

Many sites round chemotherapy doses to reduce waste and simplify preparation. Choose a rounding increment, such as 5 mg or 10 mg, and the tool will round the final dose after reductions and caps. The preparation panel estimates withdrawal volume using the concentrate strength you enter (mg/mL). It also estimates an infusion bag volume using a chosen final concentration (mg/mL). Always confirm stability and diluent rules.

Dose reductions, caps, and documentation

Protocols often apply dose reductions after specific toxicities, interactions, or hepatic impairment. Enter a reduction percentage only when it is clinically indicated and documented. If your regimen uses a maximum dose, apply a dose cap in milligrams to prevent unintentional escalation. Exporting a CSV creates a single-row audit record of inputs, calculated dose, and rounding choices for chart notes or double-checking.

Safety prompts support careful review

Irinotecan can cause early and delayed diarrhea, myelosuppression, and increased exposure with elevated bilirubin. This tool can display prompts when ANC, platelets, or liver tests suggest higher risk, and when severe diarrhea or neutropenia grades are selected. Prompts are not hold rules; they are reminders to consult prescribing guidance and institutional thresholds before releasing the order.

FAQs

What dosing approach does the tool use?

It calculates an estimated dose as BSA (Mosteller) multiplied by the selected mg/m², then applies optional reduction, cap, and rounding. It is an educational aid and must be validated against your regimen and orders.

Which body surface area formula is applied?

The calculator uses the Mosteller equation: BSA = square root of (height in cm × weight in kg ÷ 3600). Enter height and weight in the same visit to keep the estimate consistent.

When should I use BSA capping?

Enable a cap only if your institution or protocol specifically requires it. If you are unsure, leave it off and document the uncapped BSA. Policies vary by regimen and service line.

How is rounding performed?

Rounding happens after reductions and caps. The tool rounds to the nearest increment you choose, such as 5 mg or 10 mg. Confirm your pharmacy rounding standard and ensure the rounded value is clinically acceptable.

What do ANC, platelets, and liver tests change?

They do not change the dose automatically. They trigger safety prompts to encourage review when values suggest higher risk. Always follow protocol thresholds, dose-modification tables, and prescribing guidance.

Can I export more than one calculation?

CSV export includes only the latest calculation shown on the page. To build a log, download after each run and merge files, or adapt the code to store results in a database per your workflow.