anti-emetics Flashcards
aprepitat category
NK1 receptor antagonist
dose of aprepitat
40 mg 3 hours prior to induction
peak of aprepitat
3 hours
brand name aprepitat
emend
MOA aprepitat
as an anti-emetic
G protein coupled receptors found in BOTH
central and peripheral NS
also in GI tract
HIGH concentrations of these receipts in regions responsible for N/V
regions of the brain responsible for the vomiting reflex
brainstem nuclei
nucleus tractus solataries
area postrema
metabolism aprepitat
hepatic
crosses BBB
major A/E of aprepitat
fatigue nausea constipation weakness hiccups
contraindications of other medications with aprepitat
Do not combine w/ pimozide,
terfenadine,
astemizole,
or cisapride.
how does aprepitat affect warfarin?
Concurrent Warfin use decreases INR
what drugs improve aprepitat’s efficacy?
Greater efficacy for preventing vomiting than any other single intervention
*Combine w/ other anti-emetics
(5HT3 antagonist - ondansetron
or dexamethasone - steriod
category of diphenhydromine
H1 receptor antagonist
activity of diphenhydromine
anticholinergic
antimuscarinic
weak antidopaminergic
dose of diphenhydromine PONV
12.5 mg
dose of diphenhydromine allergic RXN
10-50 mg
max dose of diphenhydromine
400 mg/day
onset diphenhydromine IV
IV 2-3 minutes
onset diphenhydromine PO
15-30 minutes
peak diphenhydromine IV
30-60 minutes
peak diphenhydromine PO
2.5 hours
DOA diphenhydromine
3-6 hours
uses of diphenhydromine
PONV
allergic rxn
metabolism diphenhydromine
hepatic
SIGNIFICANT first pass
elimination diphenhydromine
urine
major A/E diphenhydromine
Drowsiness, dry mouth, blurred vision, urinary retention extrapyramidal symptoms, sedation, increased IOP
contraindications of diphenhydromine
Acute asthma,
neonates or premature infants, breast-feeding,
use as local anesthetic
category of dolasetron
Serotonin (5ht3) receptor antagonist
brand name dolasetron
anzemet
dose of dolasetron
IV 12.5 mg PONV
peak dolasetron
40 minutes
MOA dolasetron
Inhibit central and peripheral stimulation of 5ht3 receptors
metabolism dolasetron
Hepatic(plasma t ½ twice as long as ondanestron)
elimination dolasetron
urine
major adverse effects dolasetron
QTc prolongation, headache, diarrhea, serotonin syndrome (agitation, tachycardia, muscle twitching/
what is dolasetron not effective for?
chemo related N/V
category of droperidol
Dopamine receptor antagonist
other receptors antagonized include GABA, NE, and 5HT3
name all the receptors antagonized by droperidol
Dopamine- main
GABA, NE, 5Ht3
dose of droperidol
0.625- 1.25 mg IV
onset droperidol
3-10 minutes
peak droperidol
30 minutes
DOA droperidol
2-4 hours
uses of droperidol
Anti-emetic and antipsychotic.
Low doses- alpha adrenergic receptor blocker increased sedation.
Antiemetic tx for PONV at higher doses
metabolism droperidol
hepatic
crosses BBB
major A/E droperidol
QT prolonged, hypotension, torsade de pointes, depression, hallucinations, neuroleptic malignant syndrome, extrapyramidal symptoms
contraindications droperidol
Pt’s with known/suspected QT prolongation,
Parkinson’s disease,
bradycardia (
trade name droperidol
Inapsine,
warning with droperidol
2001 FDA BB warning arrhythmia and death
ondansetron category
Serotonin (5ht3) receptor antagonist
not other receptors found for droperidol
ondansetron dose
4 mg IV
onset ondansetron
30 minutes
peak ondansetron
1 hour
uses of ondansetron
Cancer induced N/V (CINV),
postoperative N/V,
radiotherapy induced N/V
metabolism of ondansetron
Hepatic (crosses BBB, limited accumulation of these drugs in CNS)
elimination of ondansetron
urine/feces
side effects of ondansetron
H/A, constipation, QTc prolongation, cardiac arrhythmia, drowsiness, serotonin syndrome (agitation, tachycardia, muscle twitching/stiffness)
ondansetron MOA
*5ht3 receptors are ligand gated Na/K channels in the CNS/PNS,
notably CTZ and afferent fibers of vagus nerve in gut and CNS;
5ht3 activation of CTZ and vagal afferents canvomiting reflex
Palonosetron category
Newest
Serotonin (5ht3) receptor antagonist
dose palonsetron
0.25 (CINV)-0.075 (PONV) mg
A/E of palonsetron
QTc prolongation,
bradycardia,
HA,
promethazine MOA
Phenothiazine derivative
and a potent antihistamine w/ moderate anti-muscarinic (anticholinergic) activity
dose of promethazine
12.5-25 mg Q4hrs
promethazine onset
~ 5 mins
promethazine DOA
4-6 hrs (up to 12 hrs)
uses promethazine
Effective rescue tx PONV, use for allergic reactions, sedative
metabolism promethazine
hepatic
promethazine adverse side effects
Altered cardiac conduction,
anticholinergic effects,
extrapyramidal symptoms,
neuroleptic syndrome
conditions that promethazine is contraindicated with
Glaucoma, myasthenia gravis, Parkinson’s disease, respiratory disease, seizure disorder
promethazine severe warning
FDA BB warning 2004: do not use in children
Metoclopramide MOA
Procainamide derivative and a benzamide prokinetic agent
metoclopramide dose
25-50 mg IV/IM
uses of metoclopramide
Most commonly used D2 receptor antagonist for antiemetic prophylaxis,
primarily for PONV and chemo associated w/ low emetogenic risk
metoclopramide metabolism
1st pass hepatic metabolism decreases bioavailability to 75%;
readily passes BBB and placenta
side effects of metoclopramide
GI obstruction, tardive dyskinesia when used beyond 12 wks., Sedation, hypotension, brady/tachycardia
contraindications of metoclopramide
Avoid after GI surgery
MOA
Central and peripheral D2 receptor antagonist activity
Also acts on peripheral D2, muscarinic, and 5HT4 receptors prokinetic activity
Enhances GI motility decreases stomach reflux/urge to vomit
