Gemcitabine

Gemcitabine in Dogs and Cats: Uses, Dosage and Side Effects

Overview

• Metabolites of the drug inhibit the enzyme ribonucleotide reductase and compete with endogenous nucleotides for incorporation into DNA strands, thereby inhibiting DNA synthesis.
• Acts primarily in the S phase.

Uses of Gemcitabine

• Used in dogs with bladder urothelial carcinoma, lymphoma and various carcinomas.
• Described for use in cats with exocrine pancreatic carcinoma.
• May also be helpful as a radiosensitizer for some tumours.

Dose of Gemcitabine in Dogs and Cats

Dogs:

• High dose: 800–900 mg/m2 i.v. over 20–60 minutes every 7–14 days for 4 doses.
• Low dose: 25–50 mg/m2 i.v. over 20–60 minutes once or twice a week as per protocols.

Cats:

• Low dose: 20–25 mg/m2 or 2 mg/kg as a 20-minute i.v. infusion every 7 days.

Side Effects of Gemcitabine in Dogs and Cats

• May cause myelosuppression and gastrointestinal adverse events.
• Retinal haemorrhage may also occur.
• Death due to treatment-related complications has been described.

Contraindications of Gemcitabine in Dogs and Cats

• Contraindicated in patients with known hypersensitivity to gemcitabine.
• Do not use in patients with preexisting bone marrow suppression.
• It should be used with caution in patients with reduced hepatic or renal function.

Some Notes:

• Limited clinical use at present.
• In humans, gemcitabine has been used in pancreatic carcinoma, small cell lung carcinoma, lymphoma, bladder and other soft tissue carcinomas.
• Seek specialist advice before using this drug.