Pharm - Anti Nausea/Vomiting Flashcards
list the serotonin (5-HT3) receptor antagonists
- dolasetron
- granisetron
- ondansetron
- palonosetron
-pitant ending indicates what drug
neurokinin (NK1) receptor antagonist
-setron ending indicates what drug
serotonin (5-HT3) receptor antagonist
list the histamine (H1) receptor antagonists
- diphenydramine
- dimenhydrinate
- hydroxyzine
- promethazine
- meclizine
- cyclizine
- doxylamine
list the dopamine (D2) receptor antagonists
- chlorpromazine
- perphenazine
- prochlorperazine
- metoclopramide
- haloperidol
list the muscarinic (M1) receptor antagonist
scopolamine
list the cannabinoid receptor agonists
- dronabinol
- nabilone
MOA of serotonin (5-HT3) receptor antagonists
blocks serotonin type-3 receptors at the vagal nerve terminal and blocks signal transmission to chemoreceptor trigger zone
(blocks serotonin-receptor activation after serotonin release from intestinal enterochromaffin cells)
therapeutic uses of serotonin (5-HT3) receptor antagonists
- chemotherapy induced N/V
- radiation-induced N/V
- post-operative N/V
- N/V of pregnancy
adverse effects of serotonin (5-HT3) receptor antagonists
- headaches
- constipation/diarrhea (serotonin syndrome)
- dose-dependent QT prolongation (torsades)
extreme caution should be used when prescribing serotonin (5-HT3) receptor antagonists with _____
QT prolonging agents
- antiarrhythmics
what patients should not be prescribed serotonin (5-HT3) receptor antagonists
hypokalemic and hypomagnesmic patients
half life of serotonin (5-HT3) receptor antagonists
all have short half-lives EXCEPT palonosetron and sustained-release formulation of granisetron
what serotonin (5-HT3) receptor antagonists should be used for delayed chemotherapy induced N/V as a single dose
- palonosetron (long half life)
- 2 branded-granisetron agents (long half life)
- sustol
therapeutic uses of neurokinin-1 receptor antagonists
- chemotherapy induced N/V
- prophylaxis of post-operative N/V
what is the only NK1 antagonist that should be used prophylactically for post-operative N/V
aprepitant
to treat chemotherapy induced N/V, NK1 antagonists should be used in combination with ____
a glucocorticosteroid and 5-HT3 antagonist
adverse effects of NK1 antagonists
- dyspepsia/constipation/diarrhea
- dizziness/fatigue/somnolence
what NK1 antagonists have longer half lives
- netupitant
- rolapitatant
what drug interactions can occur with NK1 antagonists
many - it’s a cyp450 inhibitor
MOA of H1 receptor antagonists
block histamine type 1 receptors in the vomiting center and vestibular system
- varying levels of anticholinergic properties at the level of chemoreceptor trigger zones
therapeutic uses of H1 receptor antagonists
- idiopathic, mild N/V
- post-operative N/V
- N/V of pregnancy
- motion sickness/vertigo
- chemotherapy induced N/V
- radiation induced n/V
what is the only indication for meclizine and cyclizine (H1 receptor antagonists)
motion sickness/vertigo
therapeutic use of doxylamine (H1 receptor antagonist) with pyridoxine (B6)
N/V of pregnancy
adverse effects H1 receptor antagonists
- drowsiness
- dry mouth
- constipation
- urinary retention
- blurred vision
- decreased BP
(classic anticholinergic effects)
drug interactions with H1 receptor antagonists
interactions with other agents that also induce anticholinergic related side effects
MOA of dopamine (D2) receptor antagonists
block dopamine type 2 receptors in the chemoreceptor trigger zone
- agents exhibit varying levels of anticholinergic properties
MOA of metoclopramide, other than the normal MOA of other dopamine (D2) receptor antagonists
it also stimulates acetycholine actions in the GI tract –> enhances GI motility and increases lower esophageal sphincter tone
- no impact on GI secretions
which dopamine (D2) receptor antagonist can be used to treat diabetic gastroparesis/dysmotility
metoclopramide
therapeutic uses of dopamine (D2) receptor antagonists
- idiopathic, mild N/V
- gastroparesis/dysmotility (metoclopramide)
- post operative N/V
- N/V of pregnancy
- chemotherapy induced N/V
- radiation induced N/V
adverse effects of dopamine (D2) receptor antagonists
- drowsiness
- dry mouth
- constipation
- urinary retention
- blurred vision
- decreased BP (sometimes arrhythmias)
(classic anticholinergic effects)
drug interactions with dopamine (D2) receptor antagonists
- other agents w/ anticholinergic effects
- antiarrhythmics
- antihypertensives
how is scopolamine administered
transderm scop (a patch worn for 72 hours, normally placed behind ear)
therapeutic uses for scopolamine
motion sickness
- also end of life care for excessive secretions
MOA scopolamine
block acetycholine-stimulated muscarinic receptors in neural pathways from the vestibular nuclei in the inner ear –> brain stem and from the reticular formation –> vomiting center
- significant anticholinergic properties
adverse effects scopolamine
- drowsiness
- dry mouth
- constipation
- urinary retention
- blurred vision
(classic anticholinergic effects, but does not drop BP)
drug interactions scopolamine
other agents that induce anticholinergic effects
therapeutic uses cannabinoids
- treatment-resistance chemotherapy-induced N/V
- appetite stimulation in anorexic patients due to severe disease (cancer, AIDS)
MOA cannabinoids
stimulate CB1 and CB2 receptors in the vomiting center/chemoreceptor trigger zone
- exert signal transduction effects through GPCR –> decreased excitability of neurons
- minimized serotonin release from vagal afferent terminals
adverse effects cannabinoids
- euphoria/irritability
- vertigo
- sedation/drowsiness
- impaired cognition/memory
- hallucinations
- xerostomia
- sympathomimetic (increased HR/BP)
- appetite sitmulation
compare pharmacokinetics of dronabinol and nabilone
dronabinol: large first pass effect and metabolized to one active metabolite
nabilone: metabolized to several active metabolites
drug interactions with cannabinoids
use caution when prescribing with other CNS depressants, cardiovascular agents, and sympathomimetics
compare acute, chronic, and anticipatory chemotherapy induced N/V
acute: occurs less than 24 hrs after chemo
chronic: occurs more than 24 hrs after chemo
anticipatory: occurs before chemo
describe the high-emetogenic regiment (3-drug regimen) for chemotherapy induced N/V
- NK1 receptor antagonist
- 5-HT3 receptor antagonist
- Corticosteroid (dexamethasone)
give regimen the day of the chemo (for acute N/V) and for 3 days after chemo (for chronic)
what can you add to the high-emetogenic (3 drug regimen) to form the 4 drug regimen
- may add olanzapine (D2 antagonist)
- may add cannabinoid in treatment-resistance
describe the moderate-emetogenic regiment (2 drug regimen)
- 5-HT3 receptor antagonist
- Corticosteroid (dexamethasone)
give regimen the day of the chemo (for acute N/V) and for 2 days after chemo (for chronic)
what can you add to the moderate-emetogenic (2 drug regimen) to form the 3 drug regimen
- may add NK1 antagonist or olanzapine
- may add cannabinoid in treatment resistance
describe the low-emetogenic regiment (1 drug regimen)
One of the following:
- corticosteroid
- 5-HT3 receptor antagonist
- metoclopramide
- prochlorperazine
give regimen day of (prior to) chemotherapy (for acute N/V)
describe the minimal-emetogenic regiment (0 drug regimen)
- no routine prophylaxis therapy recommended
describe the general principle of the breakthrough emesis regiment
add one agent from a different drug class to the current regimen
describe the stepped-therapy for pregnancy induced N/V
- vitamin B6 OR histamine antagonist w/ B6 OR 5-HT3
- dopamine antagonist
- steroid OR different dopamine antagonist
