Carboplatin AUC Dose Calculator

Individualized carboplatin dosing based on renal function, target AUC, and body composition. Used in ovarian, lung, and head & neck cancer protocols.

mg·min/mL
Typical range: 4–7; often AUC=5 or 6 in monotherapy.
?‍⚕️ Standard (70kg, CrCl 85)
? Elderly + CKD (age 78, Cr 1.4)
⚖️ Obese (BMI 34, AdjBW)
? Low AUC=4 (Myelosuppression risk)
Clinical safety: This calculator follows Calvert’s original method. Always verify with local protocols, and consult a clinical pharmacist. All calculations are local – no patient data transmitted.

? Calvert Formula & Carboplatin Dosing Rationale

Carboplatin is a platinum-based antineoplastic agent widely used in solid tumors (ovarian, lung, head/neck). Unlike cisplatin, carboplatin’s dose-limiting toxicity is myelosuppression, and its clearance is directly correlated with glomerular filtration rate (GFR). The Calvert formula (Calvert AH, Newell DR, Gumbrell LA, et al., 1989) revolutionized carboplatin dosing by linking systemic exposure (AUC) to renal function:

Carboplatin Dose (mg) = Target AUC × (GFR + 25)

Where GFR is estimated using creatinine clearance (Cockcroft-Gault) or measured isotopic methods. The "+25" represents non-renal clearance (mainly protein binding, extrarenal elimination). This equation provides consistent drug exposure and reduces interpatient variability in toxicity, especially thrombocytopenia.

? Cockcroft-Gault Equation (modified for weight types)

CrCl (mL/min) = [(140 – age) × weight (kg)] / (72 × Scr) (×0.85 for females). Serum creatinine (Scr) in mg/dL. To ensure precision, weight can be actual, ideal, or adjusted:

  • Ideal Body Weight (IBW) – Devine formula: Male: 50 + 0.91 × (height cm – 152.4); Female: 45.5 + 0.91 × (height cm – 152.4).
  • Adjusted Body Weight: IBW + 0.4 × (actual weight – IBW) used for obese patients (BMI > 30) to avoid overestimation of CrCl.

Clinical guidelines recommend capping GFR at 125 mL/min due to maximum renal clearance, preventing excessive doses that could cause severe thrombocytopenia. Our calculator incorporates this limit and calculates final dose with standard rounding.

Clinical case: Ovarian cancer (AUC=6)

A 62-year-old female, weight 68 kg, height 162 cm, serum creatinine 0.9 mg/dL. CrCl = 79 mL/min → GFRcapped = 79 → Dose = 6 × (79+25) = 624 mg. This aligns with common practice for carboplatin monotherapy every 4 weeks. Our tool provides immediate dose recommendations and safety warnings for extreme values.

⚕️ Therapeutic AUC Targets & Toxicity Thresholds

Therapy context Target AUC (mg·min/mL) Typical schedule
Monotherapy (ovarian, extensive-stage lung) 5–7 Every 4 weeks
Combination with paclitaxel 5–6 Day 1 every 3 weeks
Hematologic vulnerability / elderly 4–5 Reduce target AUC
High-intensity protocols 7–8 With growth factor support
Clinical Pharmacokinetic Insights & Dosing Caveats
  • AUC–toxicity relationship: Carboplatin-induced thrombocytopenia correlates directly with total AUC. The Calvert formula maintains AUC within ±20% of target, reducing interpatient variability.
  • When to re‑evaluate CrCl: Recalculate after significant weight change (>10%), new nephrotoxic drugs, or serum creatinine rise >0.3 mg/dL.
  • Dialyzed patients: This tool is NOT validated for hemodialysis or peritoneal dialysis – consult specialized protocols.
  • Measured GFR vs. Cockcroft‑Gault: If available, use isotopic GFR (⁵¹Cr‑EDTA) for highest precision; our calculator provides an accessible surrogate.
Reference: Ekhart C, et al. Clin Pharmacokinet 2008;47(4):261–71.

? Evidence & Derivation of the +25 Constant

In the original Calvert study, pharmacokinetic analysis in 18 patients revealed a linear relationship: carboplatin clearance = 1.22 × GFR + 25. The intercept (25 mL/min) reflects non-renal clearance that is independent of kidney function. The AUC for carboplatin (total free+bound) correlates with platelet nadir and is the main predictor of toxicity. Therefore the formula remains the gold standard in precision oncology, endorsed by NCCN and ESMO.

Adjusting for Renal Function: Clinical Pearls

For patients with significant renal impairment (CrCl < 20 mL/min), carboplatin is generally avoided or used at extremely reduced doses with strict monitoring. Our calculator displays a strong caution when estimated CrCl < 30 mL/min. Moreover, while Calvert uses GFR, many institutions measure CrCl from 24h urine collection; our calculator provides estimated GFR via Cockcroft-Gault as an accessible surrogate. Additional equations like MDRD or CKD-EPI may be used, but Calvert's original validation used EDTA clearance; nevertheless Cockcroft remains widely accepted.

❓ Frequently Asked Questions

The cap reduces supratherapeutic doses that would lead to excessive myelosuppression. Patients with supranormal GFR (>125) do not experience proportionate increase in carboplatin clearance; cap prevents overdosing and severe thrombocytopenia.

Adjusted body weight is recommended for patients with BMI >30 to avoid overestimation of renal function. Our calculator includes the adjusted weight option for accurate CrCl estimation.

Carboplatin AUC directly correlates with drug exposure and toxicity (platelets). Unlike BSA-based dosing, AUC-based targeting reduces interindividual variability, making Calvert formula superior in predicting clinical outcomes.

The Cockcroft-Gault equation is not validated in children. For pediatric oncology, different formulas (Schwartz) are used. This tool is intended for adults ≥18 years.
Primary references: Calvert AH, et al. (1989). Carboplatin dosage: prospective evaluation of a simple formula based on renal function. J Clin Oncol 7:1748-56. · Cockcroft DW, Gault MH (1976). Prediction of creatinine clearance from serum creatinine. Nephron. · ASCO Clinical Practice Guideline on chemotherapy dose individualization. Our implementation follows updated medical literature (last review June 2026).