Nausea and Vomiting (Exam 2) Flashcards
nausea
uneasiness of the stomach, throat or epigastric region
awareness of the urge to vomit
retching
rhythmic contraction of the abdominal muscles without actual emesis
vomiting
forcible voluntary/involuntary expulsion of gastric contents
is nausea and vomiting a disease?
No!
It is symptoms of many different conditions
vomiting center
located in the medulla oblongata of the brain within the blood brain barrier
the vomiting center is stimulated by neurotransmitters released by the
CTZ
GI tract
cerebral cortex
limbic system
vestibular systems
major neurotransmitters associated with the emetic response of the VC
seretonin (5HT3)
Nuerokinin1 receptors
histamine receptors
muscarinic receptors
dopamine receptors
types of receptors that drugs agonize to decrease N/V
corticosteroid
cannabinoid
gabaminergic
central nervous systems role in N/V
cerebral cortex and limbic system
activated by irritation of the meninges and extreme emotional triggers
the CNS pathway is triggered by
histamine (H1) receptors and GABA receptors
vestibular systems role in N/V
activated by disturbances to the vestibular apparatus in the inner ear
motion sickness and vertigo
the vestibular pathway is triggered by
H1 receptors and Ach receptors
Peripheral pathways common activators are
toxins
dissension of the GI lumen from blockage
dysmotility of the bowels by D2 and 5HT receptors
the peripheral pathway is triggered by
chemoreceptors and mechanoreceptors in the GI tract
CTZs role in N/V
readily exposed to substances circulating through the blood
NO BBB
activation of the CTZ is mediated primarily by
D2 receptors
5HT receptors
H1 receptors
NK1 receptors
causes of N/V for the cerebral cortex pathway
anxiety
raised inter cranial pressure
causes of N/V for the peripheral pathway
gastric stasis
radiation colitis
chemotherapy
causes of N/V for the CTZ
drugs
hypercalcemia
causes of N/V for the vestibular pathway
vestibular neuritis
drug induced N/V via tissue damage
Potassium chloride
NSAIDs
Iron
Opiates
Chemotherapy agents
drug induced N/V via chemoreceptors in the CNS
digoxin
dopaminergic agents
antibiotics
anticonvulsants
opiates
theophylline
chemotherapy agents
three neurotransmitters that have the most clinical relevance in drug induced N/V
D2
5HT3
NK1
acute CINV
within 24 hours after chemotherapy
delayed CINV
more than 24 hours after chemotherapy
anticipatory CINV
prior to chemotherapy when acute or delayed N/V occurred with previous courses
breakthrough CINV
emesis despite prophylactic treatment requiring rescue doses
refractory CINV
emesis during treatment cycles when prophylaxis and rescue therapy has failed
risk factors for CINV
poor emetic control with prior chemotherapy
female sex
low chronic alcohol intake
younger age
symptoms of N/V
diaphoresis
pallor
faintness
salivation
signs of N/V
malnourishment
weight loss
dehydration
laboratory tests for N/V
elevated BUN, SCr, BUN-SCr ratio
electrolyte imbalances
hypoglycemia
acid base disturbances
BMP for someone experiencing N/V
decreased Na, K, Cl and glucose
increased CO2, BUN, SCr
goal of antiemetic therapy
prevent or stop N/V without or with minimal adverse effects
is treatment the same for N/V of different medical situations?
NO
non-pharmacological management for N/V
dietary, physical or physiological changes
BRAT diet
bananas, rice, applesauce, and toast diet
bland foots to decrease N/V
simple N/V
minimal therapy
nonprescription and prescription agents
single agents usually
complex N/V
combination therapy (prescription)
factors that can be used to determine which agent to use
suspected etiology of symptoms
ability of the patient to take a dosage form
success of previous antiemetic agents
antihistamine-anticholinergic drugs treat N/V due to
motion sickness or vertigo
adverse reactions of antihistamine-anticholinergic agents
drowsiness, confusion, blurred vision, dry mouth, urinary retention, constipation and tachycardia
what type of patients are at higher risk for complications associated with antihistamine-anticholinergic agents
narrow angle glaucoma
prostatic hyperplasia
cardiovascular disease
examples of antihistamine and anticholinergic drugs
Dramamine (dimenhydrinate)
Benadryl (diphenhydramine)
Visatril, Atarax (Hydroxyzine)
Bonine, Antivert (Meclizine)
Transderm Scop (Scopolamine)
use antihistamine drugs _________________ before travel and apply a scopolamine patch _______________ prior to motion sickness triggers
30-60 minutes
4-6 hours
three main groups of dopamine antagonists
phenothiazines
butyrophenones
pro kinetic agents
phenothiazines examples
promethazine
prochlorperazine
chlorpromazine
phenothiazines are used for
gastritis
gastroenteritis
PONV
RINV
CINV
don’t use dopamine antagonists in patients with
a prolonged QT interval
or patients at risk for developing one
EPS syndrome includes
acute dystonic reactions
akathisia
pseudoparkinsonism
tardive dyskinesia
normal QTc intervals for men and women
men - under 450 milliseconds
women - under 460 milliseconds
do not give any dopaminergic antagonists when the QTc interval is above ____________ because it can cause
500 ms
torsades de pointes
doses of dopaminergic antagonists should be given ________________ before chemotherapy and _______________ prior to radiation
30-60 minutes
1-2 hours
example of butyrophenones
droperidol
haloperidol
droperidol prevents
PONV, RINV and CINV for patients intolerant to other first line agents
haloperidol has antiemetic effects at
low doses
droperidol has a _________________ regarding the potential for QT interval prolongation and __________________
FDA black box warning
cardiac arrhythmias
examples of pro kinetic agents
metoclopramide (reglan)
domperidone
metoclopramide is useful in
PONV, CINV, RINV, gastroparesis and GERD
metoclopramide increases __________________ and promotes ________________
lower esophageal sphincter tone
gastric motility
domperidone is a
FDA investigational drug protocol
domperidone minimally crosses the
BBB and less likely to cause centrally mediated adverse effects
Metoclopramide acts as a
D2 receptor antagonists in the CTZ and peripherally in the GI tract
Metoclopramide is given
30-60 minutes before meals
dronabinol is mainly used for
preventing and treating refractory CINV
oral dronabinol has antiemetic activity due to
activation of cannabinoid receptors CB1 and CB2 within the CNS
adverse effects of dronabinol
sedation
euphoria
hypotension
ataxia
dizziness
serotonin antagonists examples
ondansetron
granisetron
dolasetron
palonosetron
serotonin antagonists are used to treat
CINV, PONV, RINV
common side effects of serotonin antagonists
headache
somnolence
diarrhea
constipation
what needs to be monitored when on ondansetron or dolasetron?
does this need to be monitored when on granisetron or palonosetron?
QT prolongation
it does not include a recommendation, but patients may still be at risk
ondansetron has an off label use for
undifferentiated N/V presenting to the ED
may also be used for gastroenteritis and other medical conditions
palonosetron is the first 5HT3 antagonist approved for _________________
why?
acute and delayed CINV
it has a longer half life and higher receptor binding affinity
granisetron also comes in a ___________ form that is applied _____________ before chemotherapy and can be worn for up to ________________
patch (Sancuso)
24-48 hours
7 days
serotonin antagonists are given _____________ before radiation
1 to 2 hours
corticosteroids examples for N/V
dexamethasone
dexamethasone is used to treat
PONV, acute and delayed CINV or RINV
corticosteroids MOA for N/V
activation of the glucocorticoid receptors in the VC leads to decreased inflammation
side effects of corticosteroids for N/V
short term mainly
GI upset, anxiety, insomnia, HTN and hyperglycemia
dexamethasone is taken ______________ before chemo and _________________ before radiation
30-60 minutes
1-2 hours
NK1 receptor antagonists examples
areprepitant
fosaprepitant
netupitant
rolapitant
areprepitant is used to prevent
acute and delayed CINV and PONV
adverse effects of NK1 receptor antagonists
asthenia
dizziness
hiccups
netupitant is only available in a _______________________ and prevents _______________
combination oral product with palonosetron (Akynzeo)
acute and delayed CINV following moderate or high emetogenic chemotherapy
olanzapine (Zyprexa) has antiemetic effects primarily at
D2, 5HT2c and 5HT3 receptors
guidelines recommend the addition of olanzapine to
combination therapy for prevention of acute and delayed CINV in patients with high emetogenic chemotherapy
adverse effects of olanzapine
similar to DA antagonists
metabolic syndrome (weight gain, hyperlipidemia, hyperglycemia)
benzodiazepines are used to prevent and treat
CINV
adjunct to antiemetic agents in anticipatory N/V
benzodiazepines activate
GABA receptors in the cortex and limbic system (CNS)
main benzo for N/V
lorazepam
_______________ can occur at high doses or when __________________ are used concomitantly
respiratory depression
other central depressants (alcohol)
risk of N/V is associated with
generally one agent has a higher emetic risk over an other
chemotherapy induced NV has a ________________ system for the risk of emesis with specific cytotoxic agents
four level classification
when combining categories in the CINV classification system, always use the
highest category of the drugs to determine treatment
high emetic risk option 1 trx
NK1R antagonist
5HT3 antagonist
dexamethasone
olanzapine
high emetic risk option 2 trx
NEPA or fosnetupitant plus palonosetron
dexamethasone
olanzapine
moderate emetic risk non-carboplatin trx
5HT3 antagonist
dexamethasone
moderate emetic risk carboplatin based trx
NK1R antagonist
5HT3 antagonist
dexamethasone
low emetic risk trx
dexamethasone
or
5HT3 antagonist
or
phenothiazine type drug
minimal emetic risk trx
none
when patients who experience N/V despite optimal prophylaxis for CINV and had olanzapine may be
offered an antiemetic from another class that was administered with prophylactic treatment
(adds to standard regimen)
which area of the body is considered high emetic risk for RNIV?
total body irritation
recommendation for high emetic risk RINV
prophylaxis with 5HT3 antagonist +/- dexamethasone
which area of the body is considered moderate emetic risk for RINV?
upper abdomen
recommendation for moderate emetic risk RNIV
prophylaxis with 5HT3 antagonist +/- dexamethasone
which area of the body is considered low emetic risk RINV?
lower thorax
pelvic
creanium
cranial spinal region
head/neck
recommendation for low emetic risk RINV
prophylaxis or rescue with 5HT3 antagonist
which area of the body is considered minimal emetic risk RINV?
extremities
breast
recommendation for minimal emetic risk RINV
rescue with a dopamine antagonist or a 5HT3 antagonist
preoperative prophylactic antiemetic therapy is
usually not required
primary receptor targets for PONV
serotonin
NK1
histamine
muscarinic
dopamine
patient specific risk factors for PONV
female gender
nonsmoking status
history of motion sickness/PONV
anesthetic risk factors for PONV
use of volatile anesthetics
nitrous oxide
opiods
surgical risk factors for PONV
duration of surgery
intra abdominal surgery
ENT surgery
major gynecologic surgery
orthopedic surgery
laparoscopic surgery
additional methods to reduce PONV in combination with prophylactic antiemetic
supplemental oxygen and hydration
avoid nitrous oxide, volatile general aesthetics and opioids
use local anesthesia (propofol)
low risk for PONV
0-1 risk factors
not likely to benefit from prophylaxis
moderate risk for PONV
2-3 risk factors
one to two prophylactic antiemetic agents
high risk for PONV
4 or more risk factors
two to three prophylactic antiemetic agents
when to use scopolamine before surgery?
4 hours before the end of surgery
when to use prochlorperazine, promethazine, metoclopramide before surgery?
at the end of surgery
when to use droperidol before surgery?
at the end of surgery
(not really used because of torsades)
when to use 5HT3 receptor antagonists before surgery?
dolasetron, granisteron, ondansetron - end of surgery
palonestron - immediately prior to anesthesia
when to use dexamethasone before surgery?
at induction of anesthesia
when to use aprepitant before surgery?
3 hours prior to induction of anesthesia
hyperemesis gravidarum
severe physical symptoms and/or medical complications that may require hospitalization
can result in dehydration, weight loss and electrolyte abnormalities
intitial management for NV during pregnancy
dietary changes and/or lifestyle modifications
when is drug therapy considered in N/V during pregnancy?
persistent nausea and vomiting
what dietary supplement is recommended for NVP?
ginger
first line pharmacotherapy for NVP
pyridoxine (vitamin B6) alone or in combination with doxylamine (diclegis)
how does doxylamine have antiemetic effects?
competes with H1 receptor sites
blocks CTZ
diminishes vestibular stimulation
depresses labyrinthine function through anticholinergic activity
how does pyridoxine have antiemetic effects?
functions in the metabolism of proteins, carbs and fats
synthesis of GABA
if liquids cannot be tolerated or if dehydration occurs,
use parenteral nutrition
corticosteroid used for NVP
methylprednisolone
why is methylprednisolone considered a last resort in NVP?
causes oral clefts in the fetus
avoid the first 10 weeks of gestation
ondansetron should be avoided in the ______________ of gestation because of
first 10 weeks
given controversies about a potential small increase in risk of congenital abnormalities
