Medical therapy (Yr4) Flashcards
what is chemotherapy?
genotoxic treatment of disease using cytotoxic and other drugs
what four ways can chemotherapy be used?
primary (sole therapy)
adjuvant (after surgery)
neoadjuvant (before surgery)
concurrent (simultaneously to radiation)
what cells are targeted by chemotherapy?
rapidly dividing cells (doesn’t typically effect cells in G0) only targets DNA/RNA synthesis or protein synthesis
what factors effect chemotherapy success?
growth fraction
evolution of resistance
inherent tumour sensitivity
drug dosage
tumour blood/oxygen supply
interval between treatment
what factors effect the response and side effects to chemotherapy?
administration (dose, ability to get into blood stream…)
distribution (get to target site/blood…)
metabolism (drug activation/deactivation)
excretion (liver or kidney…)
what patients pose dosing problems for chemotherapy?
obese (dose for lean weight?)
breeds with known drug sensitivities (collies)
animals with hepatic/renal compromise
what should the starting dose of chemotherapy drugs be?
maximum tolerated dose (this is a bit of a guess)
what is the dose of chemotherapy drugs based on?
body surface area (for <10kg it is dosed for mg/kg)
why does there have to be an interval between dosing with chemotherapy drugs?
allows recovery of normal tissues
what drugs are in a CHOP protocol?
vincristine, doxorubicin, cyclophosphamide, prednisolone
what drugs are in a CEOP protocol?
vincristine, epirubicin, cyclophosphamide, prednisolone
what would be the chemotherapy protocol of choice for a dog with lymphoma?
CHOP/CEOP
what should be done prior to each chemotherapy treatment?
haematology (neutrophil and platelet counts)
what should be done prior to cyclophosphamide therapy?
urinalysis
what chemotherapy drugs cause anaphylaxis/hypersensitivity?
L-asparaginase
what chemotherapy drugs cause cardiac arrhythmias?
doxorubicin
what chemotherapy drugs cause emesis?
platinum compounds
what causes acute tumour lysis syndrome?
rapid destruction of cancer cells in patients with a large tumour burden
how is acute tumour lysis syndrome treated?
monitoring at risk patients
early IVFT
management of acute kidney injury (caused by the lysis syndrome)
what are the main general side effects of chemotherapy?
bone marrow (low WBC 7-10 days)
alopecia
GI toxicity (usually only fist 5 days)
(they all relate to rapidly dividing cells)
how can we pre-emptively manage GI toxicity from the chemotherapy drugs?
maropitant (prevent vomiting)
pre-treatment fasting to reduce diarrhoea
smectite for diarrhoea
how should pyrexic neutropenic patients 7-10 days post-chemotherapy be managed?
might be septic (this is an emergency)
hospitalise until systemically well and stop all cytotoxic drugs (reduce dose next time)
barrier nursing and antibiotics
what drug can cause cumulative cardio toxicity (DCM)?
doxorubicin
what drug can cause sterile haemorrhagic cystitis?
cyclophosphamide
what drug can cause hepatotoxicity?
lomustine (dogs)
what drugs can cause nephrotoxicity?
cisplatin, doxorubicin, lomustine
what drug can cause fatal non-cariogenic pulmonary oedema?
cisplatin
what drugs are catastrophic perivascular irritants?
doxorubicin and epirubicin
what is metronomic chemotherapy?
continuous low dose chemotherapy usually used as palliative therapy with the main target being angiogenesis
what is the typical drug used for metronomic chemotherapy?
low dose cyclophosphamide (with an NSAID)
how do tyrosine kinase inhibitors work?
inhibit activation of specific signalling pathways by specific cancer types
what are two examples of tyrosine kinase inhibitors?
toceranib and mastitinib
what are possible side effects of tyrosine kinase inhibitors?
diarrhoea, vomiting, anorexia
bone marrow suppression
