Carboplatin AUC Calculator

Variables and formulas

This tool estimates the total Carboplatin dose (in mg) based on the Cockcroft Gault equation which provides the estimated creatinine clearance level which is then adjusted by the target AUC.

The variables used are:

■ Patient gender – to be used in the Cockcroft Gault equation and in Devine’s formula;

■ Patient age – in years, to be used in the Cockcroft Gault equation;

■ Patient weight – can be input in either lbs or kg;

■ Patient height – can be specified in either ft and in or cm;

■ Serum creatinine – measured in mg/dL or µmol/L;

■ Target AUC – expected values range between 4 and 8 mg/mL/min;

The Cockcroft and Gault equations when serum creatinine is in mg/dL:

■ CrCl for male = [(140 - age) x Weight in kilograms] / (Serum Creatinine in mg/dL x 72)

■ CrCl for female = [(140 - age) x Weight in kilograms x 0.85] / (Serum Creatinine in mg/dL x 72)

The Cockcroft and Gault formulas when serum creatinine is in µmol/L:

■ CrCl for male = [(140 - age) x Weight in kilograms x 1.23] / (Serum Creatinine in µmol/L)

■ CrCl for female = [(140 - age) x Weight in kilograms x 1.04] / (Serum Creatinine in µmol/L)

The ideal body weight by Devine’s formula:

■ Male = 50 kg + (2.3 x (Height in inches - 60))

■ Female = 45.5 kg + (2.3 x (Height in inches - 60))

The ideal weight result is converted in both kg and lbs for convenience, where (1 kg = 2.20462262 lbs).

Carboplatin dose is based on the Calvert formula:

■ Dosage = Target AUC x (GFR* + 25)

*Where the GFR is provided by the eCrCl.

Carboplatin and target AUC

The carboplatin dosage value takes account of the target area concentration versus time curve and estimated GFR. There is another dosing method, that involves body surface area, however, this is not as accurate.

Target AUC values differ depending on the status of the patient:

■ For patients already treated, target AUC should be around 4 – 7 mg/mL/min;

■ For patients without previous treatment target AUC should be around 6 – 8 mg/mL/min.

It is important to note that in some cases with fluctuant serum creatinine, the estimation may not be as exact, thus it won’t lead to an accurate Carboplatin dose either.

References

1. Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976; 16(1):31-41.

2. Calvert AH, Newell DR, Gumbrell LA, et al. Carboplatin dosage: prospective evaluation of a simple formula based on renal function. J Clin Oncol. 1989; 7:1748-1756.

3. Devine BJ. Gentamicin therapy. DICP. 1974; 8:650–5.