Carboplatin (kar-bo-pla-tin) is a broad-spectrum platinum-containing antineoplastic (anticancer) chemotherapy drug sold under the brand name Paraplatin. It is used to treat a variety of carcinomas and sarcomas including squamous cell carcinoma, mediastinal carcinoma, pleural adenocarcinoma, pulmonary carcinoma, nasal carcinoma, anal sac apocrine gland adenocarcinoma, colonic adenocarcinoma, mammary gland carcinoma, urinary tract carcinoma, hepatocellular carcinoma, feline vaccine-associated sarcomas, thyroid adenocarcinoma, melanoma and osteosarcoma.
The drug is not approved for use in animals by the Food and Drug Administration (FDA), however, it can be prescribed as an extra-label treatment for cats.
Mechanism of action
Carboplatin is in the class of alkylating agents which stop tumour growth by cross-linking guanine bases in DNA double-helix strands which makes them unable to uncoil and separate which is necessary for DNA replication, thus preventing the tumour cells from dividing.
Carboplatin is administered intravenously via infusion.
How often do cats receive carboplatin?
Every 3-4 weeks.
Carboplatin is contraindicated in cats with a history of hypersensitivity to the drug or patients with severe bone marrow suppression.
Cats who are pregnant or lactating.
Carboplatin can interact with other medications which include aminoglycosides, cisplatin, myelosuppressive agents, phenytoin, radiation therapy and vaccines.
Side effects of carboplatin
Unlike humans, cats don’t experience hair loss and generally tolerate chemotherapy well. Primary adverse effects include gastrointestinal disturbances (loss of appetite, vomiting, diarrhea) and bone marrow suppression, low blood platelets (thrombocytopenia) and low neutrophils (neutropenia).
Less common adverse effects include nephrotoxicity (kidneys) and ototoxicity (ears).
A complete blood count (CBC) is a measure of the cat’s blood cells and platelets and is indicated 1, 2 and 3 weeks after the first treatment of carboplatin.
CBC before the next treatment and CBC 14-21 days after. Myelosuppression typically appears 2-3 weeks after administration of carboplatin. It may be necessary to delay chemotherapy or reduce the dose in cats who are experiencing gastrointestinal toxicity or myelosuppression.
Contact your veterinarian immediately if you notice any of the symptoms described above.
The major route of elimination is renal excretion. Your cat’s veterinarian or veterinary oncologist should provide you with a safety sheet during treatment.
- Pregnant and lactating women should not clean litter trays.
- Always use disposable rubber gloves when handling litter trays or cleaning up vomit, blood, feces or urine on the day and several days after the cat has received carboplatin.
- Seal the waste and disposable gloves in a plastic bag and dispose of them in the outside garbage.
- Wear gloves to clean accidents, and wash hands well with soap and water afterwards. If the cat has an accident on his or her bedding, wash it separately from other laundry two times.