Chapter 173 - complications of chemotherapy agents

Question 1

Dog breeds stated to be at increased risk of carrying the ABCB1 (MDR1) mutation

Answer 1

collies, shelties, Australian shepherds, old English sheepdogs, english shepherds, german shepherds, long-haired whippets, silken windhounds and variety of mixed breeds

Question 2

risk factors for ATLS

Answer 2

chemotherapy- or radiation-responsive tutor type
large tutor burdens
preexisting renal disease
dehydration

Question 3

pathophysiology of ATLS

Answer 3

lysis of tutor cells, releasing intracellular electrolytes (potassium, phosphorus), toxic byproducts including malignancy associated nephrotoxins and nucleic acids such as purine that are metabolised to uric acid. hypocalcemia develops as a sequela of elevated phosphate levels, metabolic acidosis is exacerbated by uric acid, calcium phosphate salts may be deposited in renal tubules causing further damage and intraluminal tubular obstruction

Question 4

clinical signs of ATLS

Answer 4

lethargy, vomiting, diarrhoea, bradycardia, cardiovascular collapse, renal failure and shock

Question 5

treatment of ATLS

Answer 5

cardiovascular support and correction of electrolyte abnormalities with IV fluids as needed (0.9% NaCl appropriate if hyperkalemic and hyperphosphatemic), management of hyperkalemia-associated arrhythmias, calcium if clinically hypocalcemic

Question 6

why are specific therapies such as urinary alkalinization, allopurinol and rate oxidases not currently recommended in veterinary patients with ATLS?

Answer 6

variability in production and significance of metabolites (CF human med)

Question 7

specific toxicity seen with CCNU (lomustine)

Answer 7

dose related risk of hepatoxicity

Question 8

specific toxicity seen with chlorambucil

Answer 8

neurotoxicity

Question 9

specific toxicity seen with cyclophosphamide

Answer 9

sterile hemorrhagic cystitis

Question 10

specific toxicity seen with doxorubicin

Answer 10

cumulative dose-related risk of DCM in dogs, possible renal toxicity in cats, anaphylactoid reactions in both due to mast cell degranulation, hemorrhagic colitis. necrosis, ischemia & severe soft tissue reaction if given perivascularly

Question 11

specific toxicity seen with L-asparaginase

Answer 11

pain on injection, pancreatitis, insulin resistance, anaphylaxis

Question 12

specific toxicity seen with cisplatin

Answer 12

pulmonary edema and death in cats, nephrotoxicity in dogs

Question 13

reported toxicoses seen with vinca alkaloids

Answer 13

alopecia, bone marrow suppression, GI toxicity, ileus, peripheral neuropathies