Oncologic Emergencies and Misc. Supportive Care EXAM 2 Flashcards
Which drugs have shown a higher risk of bleeding in cancer patients? Which type of cancer?
DOACs (apixaban, rivaroxaban, edoxaban, dabigatran)
-GI (esophageal, colon, gastric)
-Genitourinary cancer (bladder, prostate, cervical, kidney)
Which DOAC is likely to fail in patients who had parts of their stomach cut out or using enteral feeding
resection of the colon: apixaban
enteral feeding: Rivaroxaban
absorption is mainly in the stomach
Which drugs increases the risk for VTE while on cancer therapy?
-thalidomide
-lenalidomide
-VGEF drugs: bevacizumab
What happens in patients with Tumor Lysis Syndrome (TLS)?
killing of many cancer cells -> release of intracellular content:
-potassium -> arrhythmia
-phosphate (from DNA) -> precipitate with calcium (Ca2+ and PO4 go low, crystals form causing AKI)
-uric acid -> crystallizes in the urine causing AKI
AKI and arrhythmia
Which labs to check in patients with TLS?
-high SCr: from crystallization of uric acid or PO4 (with calcium)
-Hyperphosphatemia
-Hypocalcemia -> risk for arrhytmia
-high potassium (hyperkalemia) -> risk for arryhtmia
When is a patient at higher risk for TLS?
-chemosensitive cancer (rapidly growing)
leukemia and lymhoma
-first cycle
Which types of cancer have the highest risk for TLS?
-leukemia and lymphoma !!!
-small cell lung cancer
-germ cell tumor
(rapidly growing and chemosensitive)
-1st cycle
-large number of tumor cells (WBC >50.000, ALL > 100.000)
Which drug is used to treat hyperuricemia (uric acid)?
-Allopurinol 300 mg PO with hydration
(Xanthine oxidase inhibitor)
-Rasburicase
Oxidizes uric acid to more soluble metabolites
expensive, only used if they need to
Although not often used (very expensive), who would benefit from Rasburicase?
-TLS pts likely to need renal replacement treatment
-pts with allopurinol allergy and in need of TLS prevention
-prevention of TLS in very high-risk patients (WBC >50.000 or >100.000)
Which drugs are used to manage electrolyte disorders caused by TLS?
-loop diuretics
-sodium polystyrene (Kayexalete) or Lokelma
-insulin/dextrose, albumin
Which enzyme converts purines into uric acid, potentially causing crystallization and AKI?
Xanthine oxidase
blocked by Allopurinol
(also metabolizes 6-MP)
How does cancer cause hypercalcemia?
-release cytokines -> increase osteoclast activity -> Ca2+ goes into the blood (hypercalcemia)
-secretion of PTH-like peptides (more calcium reabsorption at the kidney)
symptoms of hypercalcemia:
-N/V, AMS, constipation, dehydration
What is calcium bound to and how does it affect the lab values?
!!!
-to albumin
if albumin is low, there is more free Ca in the blood
need to calculate the corrected calcium:
[(4 - pts albumin) x 0.8] + serum Ca
!!!!
What calcium level is considered mild hypercalcemia?
-mild hypercalcemia: corrected Ca2+: <12 mg/dl
Know equation!!
How is mild hypercalcemia from malignancy treated?
asymptomatic: fluid intake
symptomatic: hyperhydration + diuretic (loops)
avoid thiazides (increases Ca2+ reabsorption and levels)
How to treat severe hypercalcemia
> Ca2+: 14 mg/dl
-start with fluids for several hours (bc they are dehydrated)
-give bisphosphonate (nephrotoxic) after hydration
-for severe hyperkalemia: add calcitonin (decreases Ca2+)
moderate hypercalcemia is treated with fluids and bisphosphonates
What is the role of bisphosphonates in cancer therapy?
-used to treat hypercalcemia (reduces bone breakdown and Ca2+ release into the blood)
-used to treat metastasis in the bone, the cancer increases osteoclast activity to create space in the bone
What is the dose of Zoledronic acid for hypercalcemia and bone mets treatment?
hypercalcemia: 4 mg IV over 15 minutes
dose adjust if CrCl 50: 3.5 mg
bone mets: 4 mg IV q 4-12 weeks
What is the dose of Pamidronate (Aredia) for hypercalcemia and bone mets treatment?
hypercalcemia: 30 - 90 mg IV over 2 h
dose adjust if multiple myeloma and low CrCl <30: over 4-6h infusion
bone mets: 90 mg IV q 4-12 weeks
What is a common side effect of Bisphosphonates?
Osteonecrosis of the jaw (ONJ)
avoid:
-dental procedures
-dentures
What is the dose of Denosumab for bone mets?
120 mcg SC every 4 weeks
-also need calcium and vitamin D
What is the brand name of Denosumab?
Xgeva
Which Bisphosphonates are used for bone metastases?
-zoledronic acid (prostate metastases)
-Pamidronate
-add Calcium and Vitamin D supplements
Which drug is used for Spinal Cord Compression caused by cancer?
Dexamethasone 4mg IV q6h
EMERGENCY: can cause paralysis and incontinence
What might help to reduce Alopecia during cancer therapy?
Scalp cooling (in about 50%)
What helps with Mucositis during cancer therapy?
-Cryotherapy, ice in the mouth (vasoconstriction)
-salt & soda mouthwash
-lidocaine for pain
-nystatin/tetracycline - infection prophylaxis
What helps with fatigue caused by chemotherapy?
Exercise
-psychostimulants (not much data)
methylphenidate, modafinil
Which drug is used to treat Anorexia and Cachexia during cancer therapy?
-Olanzapine 2.5 mg PO daily
-Megestrol acetate (increases appetite)
What are the antidotes of Anthracyclines?
-Dexrazoxane: Zinecard, Totect
What is the antidote of 5-FU?
Uridine triacetate (Vistogard®)
What is the antidote of Methotrexate?
Glucarpidase (Voraxaze®)
What is the antidote of Mechlorethamine?
Sodium thiosulfate
(Mechlorethamine is not used often anymore)
What is the antidote of Taxanes, vincas, &
more?
Hyaluronidase
it breaks down hyaluronic acid in
connective tissue -> more fluid into the bloodstream; not an antidote per se.
