THE PET PHARMACY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

Brand Name: Palladia

Available in 10 mg, 15 mg and 50 mg tablets   
 
Background

This medication was developed to address the mast cell tumor in dogs. Normal mast cells line the body’s interfaces with the outside world (skin, respiratory tract, etc.) and become bound by antibodies directed against invading parasites. When a mast cell coated with antibodies meets a parasitic protein, a reaction occurs whereby the mast cell degranulates, which means it releases its stored inflammatory proteins. These inflammatory mediators help destroy the invader.

When mast cells become tumorous, they degranulate spontaneously creating inappropriate tissue inflammation. When mast cell tumors are malignant, they can spread through the body creating a highly inflammatory form of cancer. Mast cells tumor malignancy is commonly graded 1, 2, or 3, with 3 being the most highly invasive and malignant form.

Toceranib phosphate was developed for use against grade 2 and grade 3 mast cell tumors. Toceranib phosphate is what is called a tyrosine kinase inhibitor. It has two actions against the mast cell tumor: first it kills the tumor cells directly and second, it interferes with the tumor’s blood supply.

How this Medication is Used

Toceranib phosphate is a tablet usually given every other day to dogs with mast cell tumors. Monitoring blood tests are periodically recommended.

Side Effects

The most common side effects of toceranib phosphate include:

• Diarrhea
• Appetite loss
• Lameness
• Weight loss
• Bloody stool (either black and tarry or with fresh blood)

Notify your veterinarian if any of the above occurs.

Blood test monitoring may reveal anemia (deficiency of red blood cells), drop in neutrophil (a type of white blood cell) count, increase in renal toxin build up (azotemia), elevated blood phosphate, or drop in blood albumin level. Any of these changes warrant temporary discontinuation of the medication.

During initial testing of this product, there were five deaths considered possibly drug related. Embolic disease (abnormal blood clotting) were the most common circumstances considered to be possibly drug related. One dog died from a perforated stomach.

Some dogs have depigmentation of their nose or fur during treatment with toceranib phosphate.

Interactions with other Drugs

Use of toceranib phosphate with non-steroidal anti-inflammatory drugs can increase the risk of intestinal bleeding.

Concerns and Cautions

• Toceranib phosphate should not be considered a substitute for surgery.
  
  
• Toceranib phosphate is typically administered every other day. The dose is frequently altered based on the response.
  
  
• It is important to wash your hands after handling this medication. Do not break the tablets as they have a special coating.
  
  
• If the dog spits out the tablet or the tablet gets wet in any way, use gloves to handle the tablet.
  
  
• Wear protective gloves when handling the stool, vomit, or urine of a dog using toceranib phosphate. Seal the waste in a plastic bag before placing it in the trash so as to minimize exposure of other people to the trash. Any laundry items contaminated with stool, vomit or urine of a dog on toceranib phosphate should be washed separately.
  
  
• There is presently inadequate information to recommend this medication for use in cats or in dogs weighing less than 11 lbs.

The manufacturer of toceranib phosphate (Pfizer Animal Health) has created this client information sheet/product insert and recommends that it accompany each prescription. More information can also be located at www.mypalladia.com.

Date Published: 10/2/2009 4:56:00 PM