Carboplatin

Carboplatin is a platinum-containing antineoplastic agent used in veterinary oncology for several solid tumors. A major application is adjuvant chemotherapy for canine appendicular osteosarcoma after local tumor control. It is also used in selected feline cancers. Compared with cisplatin, its clinical profile generally involves less renal toxicity and greater emphasis on bone-marrow suppression.

Group

Platinum antineoplastic

Mechanism of Action

Following intracellular activation, reactive platinum species bind mainly to purine bases in DNA and form predominantly intrastrand, with some interstrand, cross-links. These lesions distort DNA, interfere with replication and transcription, and activate cellular damage responses that can lead to apoptosis. Carboplatin is cell-cycle nonspecific, although proliferating tumor cells are particularly affected by disrupted DNA function.

Dose Rates

Dogs

Use / stage	Dose	Route	Schedule	Instructions
Cancer chemotherapy	Reference only	IV		300 mg/m² intravenously every 3 weeks, often for 4–6 cycles. Body-surface-area dosing is outside the schema calculator.
Alternative cancer chemotherapy	Reference only	IV		300–350 mg/m² IV every three weeks. Do not convert surface-area doses to a universal mg/kg amount.

Cats

Use / stage	Dose	Route	Schedule	Instructions
Cancer chemotherapy	Reference only	IV		200–227 mg/m² intravenously every 4 weeks for four treatments. The example equivalence of 14.7 mg/kg applies only to the cited 4 kg cat.
Alternative cancer chemotherapy	Reference only	IV		180–260 mg/m² IV every three weeks; surface-area arithmetic is outside the current calculator.

Rabbits

Use / stage	Dose	Route	Schedule	Instructions
Alternative cancer chemotherapy	Reference only	IV		180–260 mg/m² IV every three weeks; surface-area arithmetic is outside the current calculator.

Indications

Adjuvant chemotherapy for canine osteosarcoma after amputation or other definitive local treatment, aimed at delaying metastatic progression.
Treatment of selected canine and feline carcinomas, including squamous cell, nasal, thyroid and other epithelial tumors, within tumor-specific oncology protocols.
Treatment of selected canine melanomas and sarcomas, often in combination or adjunctive protocols with variable tumor-specific response.
Intralesional treatment of selected equine cutaneous tumors, including sarcoids, in specialist oncology practice.

Contraindications

Kidney impairment requires avoidance or dose reduction proportional to reduced clearance.
Small dogs may have greater toxicity with surface-area dosing.
Platinum hypersensitivity or severe marrow suppression; allow blood counts to recover before subsequent treatment.
Do not administer carboplatin intramuscularly or subcutaneously.

Interactions

Avoid other nephrotoxic medicines.

Adverse effects

Myelosuppression, anemia, leukopenia and thrombocytopenia
Vomiting, anorexia, diarrhea and gastroenteritis

Toxicity

Bone marrow suppression limits dosing. Renal impairment increases exposure and gastrointestinal toxicity.

Preparations

Preparation	Form	Strength	Route
Carboplatin 50 mg vial Strength is per vial; no final mL concentration is implied.	Injection	50 mg / vial	IV
Carboplatin 150 mg vial Strength is per vial; no final mL concentration is implied.	Injection	150 mg / vial	IV
Carboplatin 450 mg vial Strength is per vial; no final mL concentration is implied.	Injection	450 mg / vial	IV
Carboplatin 10 mg/mL injection	Injection	10 mg / mL	IV

Monitoring and Administration

Check CBC and platelets before each treatment and again 7–14 days afterward. Typical marrow nadirs are around day 14 in dogs and day 21 in cats, with later recovery.

Do not use aluminum-containing administration equipment. Handle as a cytotoxic medicine.

Monitor electrolytes, renal and hepatic function as well as CBC. A 50 mg vial made to a final 5 mL yields 10 mg/mL; infusion commonly takes about 15 minutes.

Chemical stability reports do not establish sterility. For the preservative-free reconstituted product described in the supplement, discard unused solution after eight hours; longer one-month potency claims from a different formulation must not be generalized.