CINV Flashcards
what are some triggers to the chemoreceptor trigger zone
pregnancy, cytotoxic agents
what occurs upon afference impulses to vomiting center (VC)
efference impulses to salivation, resp, GI muscles
define acute CINV
n/v occurring within 24 hours of chemo
define delayed CINV
n/v occurring at least 24 hours post-chemo, often peaks 48-72 hours
define breakthrough CINV
n/v that occurs within 5 days post chemo despite optimal anti-emetic regimen used; requires rescue therapy with other antiemetics
define refractory CINV
n/v that occurs in subsequent chemo cycles despite maximum antiemetic protocol
define anticipatory CINV
n/v triggered by sensory stimuli associated with chemo admin
risk factors for CINV
females, history of motion sickness, previous CINV, pregnancy, younger age, anxiety (anticipatory)
what is the goal of antiemetic therapy
complete prevention (0-1 episodes/24 hours) for at least 3 days for high risk (HEC) or 2 days for moderate risk (MEC) after the last dose of chemotherapy
which drug class is the foundation of most CINV prophylaxis
the “setrons” - aka 5-HT3 RA
ondansetron, granisetron, palonosetron
which setron is best for delayed emesis
palonosetron
side effects of the setrons
headache, constipation
route/dose dependent risk of QT prolongation (mostly with IV ondansetron >16 mg)
which class of antiemetics is a good preventative for HEC, ESPECIALLY delayed CINV, but NOT for breakthrough
NK-1 inhibitors
aprepitant
fosaprepitant
drug interactions with the NK-1 inhibitors?
inhibits metabolism of dexamethasone so must reduce dexamethasone dose by 50%
other important CYP3A4 interactions (ex do not combine with ifosfamide)
which class of antiemetics is good for acute emesis, delayed emesis, HEC, MEC, even low emesis regimens but
NOTTTTT for brain tumors??
adrenal corticosteroids- dexamethasone!
pearls for dexamethasone?
dose reduce with aprepitant/fosaprepitant
may be modified when the chemo regimen already includes a steroid
not recommended with immunotherapies
not used in brain tumors
adverse effects of dexamethasone
HTN, DM, GI upset/bleeding, agitation, itching, nerves, vomiting
which drug is the newest preventative, also used for breakthrough CINV, can be used prn or for palliative care nausea, and has replaced haloperidol in many settings
olanzapine
olanzapine adverse effects
increased risk of EPS when used with metoclopramide or haloperidol
QT prolongation
CNS depression
risk for falls in elderly
orthostatic hypotension
which drug classes are used for prevention
setrons
NK-1 inhibitors
adrenal corticosteroids
olanzapine
which drug classes are used for breakthrough
benzodiazepines (lorazepam)
metoclopramide
cannabinoids
phenothiazines or haloperidol
how is lorazepam used for CINV?
it is not a true antiemetic, more an amnestic. helpful for anticipatory emesis when started prior to triggers
side effects of metoclopramide
EPS
what cannabinoid may be used for breakthrough CINV
dronabinol. also useful for appetite
no evidence supports marijuana over this