Another approach for determining the initial dose of carboplatin is the use of mathematical formulas, which are based on a patient’s pre-existing renal function or renal function and desired platelet nadir. Renal excretion is the major route of elimination for carboplatin. The use of dosing formulas, as compared to empirical dose calculation based on body surface area, allows compensation for patient variations in pretreatment renal function that might otherwise result in either underdosing (in patients with above-average renal function) or overdosing (in patients with impaired renal function). A simple formula for calculating dosage, based on a patient’s glomerular filtration rate (GFR in ml/min) and carboplatin target area under the concentration versus time curve (AUC in mg/mL•min), has been proposed by Calvert. In these studies, GFR was measured by 51Cr-EDTA clearance.

The target AUC of 4 mg/ml•min to 6 mg/ml•min using single-agent carboplatin appears to provide the most appropriate dose range in previously treated patients. This study also showed a trend between the AUC of single-agent carboplatin administered to previously treated patients and the likelihood of developing toxicity.

Because renal function is often decreased in elderly patients, formula dosing of carboplatin based on estimates of GFR should be used in elderly patients to provide predictable plasma carboplatin AUCs and thereby minimize the risk of toxicity.

Carboplatin Injection is a premixed aqueous solution of 10 mg/ml carboplatin. Carboplatin aqueous solution can be further diluted to concentrations as low as 0.5 mg/ml with 5% Dextrose in Water (D5W) or 0.9% Sodium Chloride Injection, USP. When prepared as directed, carboplatin aqueous solutions are stable for 8 hours at room temperature (25°C). Since no antibacterial preservative is contained in the formulation, it is recommended that carboplatin aqueous solutions be discarded 8 hours after dilution.

Store at a temperature not exceeding 25°C in a dry place. Protect from light. Do not freeze.

Initial Treatment of Advanced Ovarian Carcinoma: Carboplatin injection is indicated for the initial treatment of advanced ovarian carcinoma in established combination with other approved chemotherapeutic agents. One established combination regimen consists of carboplatin and cyclophosphamide. Two randomized controlled studies conducted by the NCIC and SWOG with carboplatin versus cisplatin, both in combination with cyclophosphamide, have demonstrated equivalent overall survival between the two groups. There is limited statistical power to demonstrate equivalence in overall pathologic complete response rates and long-term survival (≥3 years) because of the small number of patients with these outcomes: the small number of patients with residual tumor <2 cm after initial surgery also limits the statistical power to demonstrate equivalence in this subgroup. Secondary Treatment of Advanced Ovarian Carcinoma: Carboplatin is indicated for the palliative treatment of patients with ovarian carcinoma recurrent after prior chemotherapy, including patients who have been previously treated with cisplatin. Within the group of patients previously treated with cisplatin, those who have developed progressive disease while receiving cisplatin therapy may have a decreased response rate.