The following information covers some of the more common drugs used at home to treat cancer. Which drugs are used will depend both on which disease your pet has and what other therapies are being pursued. If you have any questions about the medications here, please talk to your doctor or a staff member.

Targeted Therapy

There are many new drugs available to treat cancer (and various other diseases as well) that are not actual chemotherapy, but instead work by targeting the suspected genetic mutations involved in cancer cell growth. While there are new targeted therapies coming out all the time, the main three used here are masitinib, dasatinib, and toceranib. These medications can be used alone, but they work best when combined with other oral and/or injectable therapies.

Side effects to these medications are very rare and can often times be stopped with minor dose adjustments. We’ve also learned a lot about dosing over the years. We habitually dose below the ‘recommended’ amount without seeing a loss of efficacy, while also avoiding most/all of the side effects from the medication. Possible side effects to all targeted therapies include bone marrow suppression and GI upset, such as vomiting or diarrhea.

Some rare side effects that we monitor for that are specific to commonly used targeted therapies:

• Masitinib can also cause a protein losing nephropathy (protein loss through the kidneys), so watch for a change in drinking and urination habits at home. We will monitor for any changes in blood work here at the clinic.
• Toceranib can cause ulcers and bleeding of the GI tract that you would see at home as frank (red) blood in the vomit or stools, ‘coffee ground’ appearance to vomit, or stools/diarrhea that are tarry and/or dark. If you notice any of these side effects, please let you doctor know right away.
• Dasatinib is especially prone to causing diarrhea, nausea, and vomiting so we typically prescribe an ‘antidote’ that is given one hour prior to the dasatinib to help prevent these side effects. However, if your pet still has trouble tolerating the medication, a dose adjustment often takes care of the issue.