DOSAGE AND ADMINISTRATION
NOTE: Aluminum reacts with carboplatin causing precipitate formation and loss of potency, therefore, needles or intravenous sets containing aluminum parts that may come in contact with the drug must not be used for the preparation or administration of Carboplatin Injection.
Single Agent Therapy
Carboplatin Injection, as a single agent, has been shown to be effective in patients with recurrent ovarian carcinoma at a dosage of 360 mg/m2 IV on day 1 every 4 weeks (alternatively see Formula Dosing). In general, however, single intermittent courses of Carboplatin Injection should not be repeated until the neutrophil count is at least 2,000 and the platelet count is at least 100,000.
Combination Therapy with Cyclophosphamide
In the chemotherapy of advanced ovarian cancer, an effective combination for previously untreated patients consists of:
Carboplatin Injection - 300 mg/m2 IV on day 1 every four weeks for six cycles (alternatively see Formula Dosing).
Cyclophosphamide - 600 mg/m2 IV on day 1 every four weeks for six cycles. For directions regarding the use and administration of cyclophosphamide please refer to its package insert. (see CLINICAL STUDIES.)
Intermittent courses of Carboplatin Injection in combination with cyclophosphamide should not be repeated until the neutrophil count is at least 2,000 and the platelet count is at least 100,000.
Dose Adjustment Recommendations
Pretreatment platelet count and performance status are important prognostic factors for severity of myelosuppression in previously treated patients.
The suggested dose adjustments for single agent or combination therapy shown in the table below are modified from controlled trials in previously treated and untreated patients with ovarian carcinoma. Blood counts were done weekly, and the recommendations are based on the lowest post-treatment platelet or neutrophil value.
|Platelets||Neutrophils||Adjusted Dose* (From Prior Course)|
Carboplatin Injection is usually administered by an infusion lasting 15 minutes or longer. No pre- or post-treatment hydration or forced diuresis is required.
Patients with Impaired Kidney Function
Patients with creatinine clearance values below 60 mL/min are at increased risk of severe bone marrow suppression. In renally-impaired patients who received single agent Carboplatin Injection therapy, the incidence of severe leukopenia, neutropenia, or thrombocytopenia has been about 25% when the dosage modifications in the table below have been used.
|Baseline Creatinine Clearance||Recommended Dose on Day 1|
|41 – 59 mL/min||250 mg/m2|
|16 – 40 mL/min||200 mg/m2|
The data available for patients with severely impaired kidney function (creatinine clearance below 15 mL/min) are too limited to permit a recommendation for treatment.
These dosing recommendations apply to the initial course of treatment. Subsequent dosages should be adjusted according to the patient's tolerance based on the degree of bone marrow suppression.
Another approach for determining the initial dose of Carboplatin Injection is the use of mathematical formulae, 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. (see CLINICAL PHARMACOLOGY.) The use of dosing formulae, 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 upon a patient's glomerular filtration rate (GFR in mL/min) and Carboplatin Injection 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.
|CALVERT FORMULA FOR CARBOPLATIN DOSING|
|Note: With the Calvert formula, the total dose of Carboplatin Injection is calculated in mg, not mg/m2.|
|Total Dose (mg) = (target AUC) × (GFR + 25)|
The target AUC of 4 mg/mL∙min to 6 mg/mL∙min using single agent Carboplatin Injection 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 Injection administered to previously treated patients and the likelihood of developing toxicity.
|AUC (mg/mL∙min)||Gr 3 or Gr 4|
|Gr 3 or Gr 4|
|4 to 5||16%||13%|
|6 to 7||33%||34%|