Cancer Chemotherapy Toxicity Flashcards
Types of Chemotherapy-induced nausea and vomiting (CINV)
acute, delayed, and anticipatory
What’s considered acute Chemotherapy-induced nausea and vomiting (CINV)
N + V that starts a few hours after chemo and usually does not persist beyond 24 hours.
Incidence of acute CINV
over 90% of patients receiving highly emetogenic chemo (cisplatin, cyclophosphamide)
Patient-related risk factors for acute CIVN
- younger age
- female
- past hx of low alcohol intake
- poor control of sx in prior cycles
- hx of motion sickness or nausea in pregnancy
Neurotransmitter responsible in acute CIVN
- serotonin (5-HT3 receptors) is most responsible
- type 2 dopamine (neurokinin-1 receptors)
How chemo and radiation therapy causes acute CINV?
Therapy causes enterochromaffin cells lining the GI tract to release serotonin in large amounts, activating 5-HT3 receptors in the GI tract, which stimulate the vomiting centre in the medulla oblongata.
What’s considered delayed Chemotherapy-induced nausea and vomiting (CINV)
Begins at least 24 hours after administration of chemo and may last for 6-7 days.
Most common drugs causing acute CINV
Cisplatin and cyclophosphamide
What drugs cause delayed CINV?
Cisplatin and cyclophosphamide
Incidence of delayed CINV
as high as 80%
Neurotransmitter responsible for delayed CINV
- substance P-dependent mechanisms appear to play a significant role
- serotonin is less important
What’s considered anticipatory Chemotherapy-induced nausea and vomiting (CINV)
Is a conditioned or learned response to previously poorly managed nausea and vomiting in chemo patients.
Incidence of anticipatory CINV
~25% patients by the 4th course of chemo
When anticipatory CINV happens?
Occurs before, during or immediately after chemo administration but before acute nausea and vomiting would be expected to occur.
Does anticipatory CINV worsens with each cycle of chemo?
Yes
How many patients refuse to continue tx because of the intolerance of N+V in anticipatory CINV?
up to 30% of patients
What are the goals of therapy in CINV?
- Prevent or minimize acute, delayed and anticipatory N+V to maintain: (a) quality of life, (b) help patient adherence with active tx, and (c) avoid treatment delays.
- Decrease incidence and severity of N+V, if it has started, and maintain patient comfort.
- Prevent complications.
What are some complications of CINV?
- esophageal tears
- dehydration
- anorexia
- malnutrition
- weight loss
- pathological bone fractures
- metabolic alkalosis
- chloride and potassium depletion
How to assess CINV?
- A thorough hx including:
- onset and duration of sx
- timing of N and/or retching and/or V
- description of the vomiting episode
- medications - Physical examination with particular attention to:
- orthostatic pressure
- abdominal pain, distention, constipation, hemorrhage
- neurologic assessment including cranial nerves, vestibular and pupillary functions, extrapyramidal signs - Lab tests:
- electrolytes: urea, creatinine, sodium, potassium, chloride, calcium, albumin
- drug screening: such as digoxin if suspected as a cause of N+V
Why would you test for chloride in CINV?
to assess hydration status
Why would you test for albumin in CINV?
to assess for hypercalcemia
Other causes for N+V, besides CINV
- fluid/electrolyte abnormalities
- bowel obstruction
- CNS or hepatic metastases
- infections
- radiation therapy
Other drugs, besides chemo, causing N+V
- opioids
- digoxin
- antibiotics
What could increase the risk of N+V when taking an emetogenic drug?
< 50 yoa
female gender
motion sickness
nausea in pregnancy
chemotherapy-induced nausea and vomiting (CINV)
