Question 1

What is Lapatinib used for?

Accepted Answer

Lapatinib is indicated for: Mammary carcinoma (investigational).

Question 2

What routes can Lapatinib be administered by?

Accepted Answer

Available routes: PO.

Question 3

Which species have cited Lapatinib dosing data?

Accepted Answer

Lapatinib dosing in the ExoticRx formulary covers 2 species: Cat (Domestic), Dog (Domestic).

Question 4

Is Lapatinib a controlled substance?

Accepted Answer

Lapatinib is not federally scheduled as a controlled substance, but is veterinary prescription only in most jurisdictions.

Question 5

What are the warnings or contraindications for Lapatinib?

Accepted Answer

Experimental in veterinary oncology. Hepatotoxicity, GI toxicity, and cardiac effects possible. Monitor liver enzymes. Limited veterinary data.

Question 6

What are the side effects of Lapatinib?

Accepted Answer

Experimental in veterinary oncology. Hepatotoxicity, GI toxicity, and cardiac effects possible. Monitor liver enzymes. Limited veterinary data.

Question 7

How does Lapatinib work?

Accepted Answer

Dual tyrosine kinase inhibitor of EGFR (ErbB1) and HER2 (ErbB2). Blocks downstream MAPK and PI3K/Akt signaling. Investigational in canine mammary carcinoma.

Species	Route	Dose	Frequency	Evidence	Source
Dog (Domestic)	PO	10–25 mg/kg	q24h	Extrapolated	Papich Handbook of Veterinary Drugs, 5th Ed
Cat (Domestic)	PO	10–25 mg/kg	q24h	Extrapolated	Papich Handbook of Veterinary Drugs, 5th Ed

Lapatinib

Drug Class

Routes

Indications

Mechanism of Action

Side effects & warnings

Species with Lapatinib dosing data (2 dose rules)

Evidence levels across 2 dose rules

Backed by a published primary source

Sample dosing (2 of 2 cited rules)

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