Treatment of Nausea and Vomitting Flashcards
Vomiting?
A physiological response that comes as a result of stimulation of the
chemoreceptor trigger zone (CTZ) and/or the vomiting centre in the
CNS.
Aetiology of N & V?
- GI mechanisms
- Cardiovascular disease
- Neurologic processes
- Metabolic Disorders
- Psychiatrist causes
- Therapy induced causes
- Drug withdrawl
- Other causes: pregnancy, noxious, poperative procedure
Chemical transmitters involved in N & V?
Dopamine-D2
Acetylcholine
Histamine
Serotonin
Antiemtics defintion?
Antiemetic drugs are medicines that ease nausea or vomiting
Antiemtics?
A. H 1Receptor Antagonists
B. Muscarinic Receptor Antagonists
C. D 2Receptor Antagonists
D. 5HT 3Receptor Antagonists
E. Substance P (NK1) Antagonists
F. Other
H 1Receptor Antagonists I?
*NV induced by any stimuli
*Vomiting produced by substances acting directly on
the CTZ
*Motion sickness, substances acting on the stomach
H 1Receptor Antagonists drugs?
Cyclizine
Cinnearizine
Buclizine
Doxylamine
Promethazine
H 1Receptor Antagonists MOA?
Mostly 1st generation anƟhistamines → enter
the CNS
Cyclizine MOA?
Inhibition H 1receptors in the VC (also has antimuscarinic action)
Cyclizine I?
Used for all types of vomiting including motion sickness
Cyclizine Kinetics?
A, D, M & E.
A=well orally
D=does not readily cross
BBB
M=extensively in liver, E=inactive
metabolites in urine, DOA=4‐6 hrs
Cyclizine AE?
Drowziness, xerostomia
Cyclizine CI?
closed‐angle glaucoma, urinary retention, prostatic hypertrophy, chronic pulmonary disease, acute asthma
Cyclizine DI?
CNS depressants,
anƟcholinergics➡️ ⬆️anƟcholinergic effects
Doxylamine MOA?
competes for H 1‐receptors sites on target
cells; has anƟcholinergic effects ➡️ depresses
labyrinthine function, blocks CTZ; diminishes
vestibular stimulation
Doxylamine I?
Used for all types of vomiting including motion sickness
Doxylamine Kinetics?
A=well absorbed orall, D=crosses BBB,
M=hepatic
E=urine
T 1/2=10‐12 hrs
Doxylamine AE?
tachycardia
urinary retention
constipation
drowsiness
blurred vision
Doxylamine CI?
children <12 yrs
Doxylamine DI?
CNS depressants,
anƟcholinergics➡️ ⬆️anƟcholinergic effects
Cinnarizine MOA?
Inhibition (‐) H 1receptors in the VC & vestibular
system (also has antimuscarinic action; CCB)
Cinnarizine I?
motion sickness, vestibular disorders
(Meniere’s)
Cinnarizine Kinetics?
A=fairly rapid
D=91% protein bound
M=extensively in liver
E=excreted unchanged in
faeces, metabolites in urine, t 1/23‐6 hrs ?
Cinnarizine AE?
extrapyramidal symptoms + depressive
feeling (with prolonged therapy), hypotension
(at high doses)
Cinnarizine CI?
hypersensitivity to the drug
Cinnarizine DI?
CNS depressants, anticholinergics,
antihistamines, MAOIs, tricyclic antidepressants
Buclizine (long‐acting)
MOA?
(‐) H 1receptors in the VC & vestibular system (also has anticholinergic properties)
Buclizine (long‐acting) I?
motion sickness, radio/chemo‐induced NV
Buclizine (long‐acting) A/E?
sedation
dizziness
headache
anxiety
hypotension
tight chest
dry mouth
urinary retention
Buclizine (long‐acting) CI?
asthma, pulmonary disease, bladder neck
obstruction, closed‐angle glaucoma
Buclizine (long‐acting) DI?
CNS depressants
Promethazine HCL
MOA?
(‐) D 2, muscarinic and H 1receptors,
crosses BBB
Promethazine HCL I?
all types of vomiting including severe morning
sickness in pregnancy (only if absolutely
essential), prevention of motion sickness
Promethazine Kinetics?
A=well orally
D=crosses BBB,
M=extensively in liver, E=inactive conjugates in
urine, T 1/2= 10‐14hrs
Promethazine Kinetics A/E?
strong sedative effect
dizziness
Fatigue,
incoordination
extrapyramidal symptoms
Promethazine CI?
children <2yrs
Promethazine DI?
CNS depressants, anticholinergic agents
Hyoscine MOA?
(‐) M receptors, blocks impulses from the
CTZ to the vomiting centre (act directly on the
VC)
Hyoscine I?
motion sickness, nausea as a result of labyrinth disturbances
Hyoscine Kinetics?
A, D, M & E?
A=poor orally
D=unclear
M=in liver,
E=in urine
Hyoscine AE?
drowsiness
dry mouth
dry skin
blurred vision, urine retention (at high doses)
constipation
dementia
Hyoscine CI?
glaucoma
GI obstruction
porphyria
Hyoscine DI?
tricyclic antidepressants, antihistamines,
antipsychotics
D2 Receptor Antagonists drugs?
Domperidone [(CTZ), peripheral actions]
Droperidol(butyrophenone, (‐) GIT)
Metoclopramide [(‐) CTZ & GIT]
Prochlorperazine (phenothiazine, (‐) CTZ)
D2 Receptor Antagonists drugs?
Domperidone [(CTZ), peripheral actions]
Droperidol(butyrophenone, (‐) GIT)
Metoclopramide [(‐) CTZ & GIT]
Prochlorperazine (phenothiazine, (‐) CTZ)
D2 Receptor Antagonists I?
NV caused by motion sickness or other labyrinth
disturbances
*Chemotherapy induced NV (CINV)
*Post Operative NV (PONV)
*Radiation Induced NV (RINV)
D2 Receptor Antagonists A/E?
sedation
dizziness
dyskinesia
dystonias
Domperidone MOA?
(‐) D 2receptors in the CTZ, to prevent the
action of circulation emetic agents
Domperidone I?
post‐operative NV, NV of central/peripheral
origin
Domperidone Kinetics?
A, D, M & E?
A=well absorbed orally, D=limited entry into the CNS (poor lipid‐solubility)
M=in liver by CYP3A4 enzymes, E=65% in faeces and 35% in urine (as metabolites), T 1/2=7‐8 hrs
Domperidone A/E?
Extrapyramidal symptoms (⬇️), drowsiness,
headache, reversible galactorrhoea
Domperidone CI?
hepatic impairement, GI obstruction or perforation, GI haemorrhage, cardiovascular
disease
Domperidone DI?
CYP3A4 inhibitors
potassium depleting agents, macrolides
antacids
anticholinergics
protease inhibitors
Droperidole ?
(‐) D 2receptors at the CTZ
Droperidole I?
prevention of PONV where other treatments
are ineffective or inappropriate
Droperidole Kinetics?
D & M
D=rapid crosses BBB
M=in liver, T 1/2=2‐3 hrs
Droperidole A/E?
Extrapyramidal symptoms, drowsiness,
hypotension
blurred vision, anxiety
Droperidole CI?
electrolyte imbalance, Parkinson’s, severe
depression, pregnancy
Droperidole DI?
alcohol, K‐depleting diuretics,
glucocorticoids, CNS depressants, opioids,
Bromocriptine, levodopa, CYP3A4/1A2
inhibitors➡️⬆️ risk of QT prolongaƟon
Metoclopramide MOA?
(‐) D 2receptors in the CTZ and VC, also has a
stimulant effect on the GIT (facilitates emptying of
the stomach, relaxes the pylorus and increases GI
motility)
Metoclopramide I?
vomiting caused by uraemia, radiation
GIT disorders
drug related NV (cytotoxic drugs)
PONV
Metoclopramide CI?
epilepsy
phaeochromocytoma, mechanical bowel
obstruction
intestine perforation
Metoclopramide Kinetics?
A, D & M.
A=rapid oral absorption; bioavailability 30‐100% due to first‐pass metabolism
D=widely distributed and readily crosses BBB
M=in the liver, E=85% unchanged in urine, T 1/2=4‐6 hrs
Metoclopramide A/E?
extrapyramidal symptoms, light sedation,
consƟpaƟon
⬆️ prolacƟn release➡️
galactorrhoea
MetoIclopramide D
antipsychotic agents, CNS depressants,
digoxin, paracetamol, ampicillin, tetracyclines
Prochlorperazine
MOA?
(‐) D 2receptors in the CTZ, also (‐) cholinergic and ∝‐adrenergic receptors➡️sedation, muscle relaxation, hypotension.
Prochlorperazine I?
vomiting due to uraemia, radiation,
oncotherapy
viral gastroenteritis severe
morning sickness (if absolutely essential)
Prochlorperazine CI?
CNS depression
coma bone‐marrow
suppression
Prochlorperazine kinetics?
A ,D, M & E?
A=well absorbed orally
D=well distributed including CNS
M=extensively metabolised in liver
E=excreted in urine and
bile, DOA=3‐4 hrs
Prochlorperazine A/E?
extrapyramidal
constipation, dry mouth,
drowsiness, blurred vision, hypotension, reflex
tachycardia
Prochlorperazine DI?
CNS depressants
anti‐Parkinson’s agents,
metoclopramide(↑extrapyramidal SE)
5HT 3Receptor Antagonists Drugs?
Granisetron
Ondansetron
Palonosetron
5HT 3Receptor Antagonists I?
Vomiting caused by cytotoxic anti‐cancer drugs,
post‐operative NV
radiation‐induced NV
(oncotherapy)
5HT 3Receptor Antagonists A/E?
headache
Dizziness
muscle pains
GIT upsets
constipation
Granisetron MOA?
(‐) 5HT 3in vagal nerve terminals and
centrally in CTZ (selecƟve) → anƟemesis
Granisetron I?
Post‐cytotoxic chemo‐/radiotherapy NV, PONV
Granisetron CI?
hypersensitivity to any of the ingredients
Granisetron Kinetics?
A=rapid and complete orally,
bioavailability 60% due to first‐pass effect
D=extensively; 65% plasma protein binding
M=in liver
E=predominantly by hepatic
metabolism, unchanged in urine, some in
faeces, T 1/2= 9 hrs
Granisetron DI?
QT prolonging agents, serotonergic agents,
cardiotoxic drugs, phenobarbital
Granisetron AE?
headache
dizziness
muscle pains
GIT upsets
constipation
Ondansetron MOA?
(‐) 5HT 3in vagal nerve terminals and
centrally in CTZ (selecƟve) → anƟemesis
Ondansetron Kinetics?
A, D, M & E.
A=well absorbed orally; bioavailability slightly enhanced by food
D=extensively
distributed; slowly crosses BBB
M&E=extensively metabolised and excreted in
the urine and faeces
Ondansetron I?
Post‐cytotoxic chemo‐/radiotherapy NV, PONV
Ondansetron AE?
headache
flushing
Constipation,
dry mouth
sedatio
hypersensitivity reactions,
seizures
CVS effects (arrhythmia, bradycardia, hypotension), fatique
Ondansetron CI?
congenital long QT syndrome, concomitant use of apomorphine
Ondansetron DI?
tramadol, rifampicin, carbamazepine,
phenytoin
Palonosetron MOA?
selectively (‐) 5HT 3receptors both peripheral and CNS with primary effects in GIT
Palonosetron Kinetics?
A, D, M & E
A=low oral bioavailability
D=widely distributed (62%
protein bound)
M=in liver (CYP2D6, CYP3A, CYP1A2)
E=urine (80‐93%),
faeces (5‐8%), T 1/2=40 hrs
Palonosetron I?
Post‐cytotoxic chemo‐/radiotherapy NV, PONV
Palonosetron A/E?
AE: anxiety, dizziness, headache, weakness,
consƟpaƟon, pruritus, hyperkalaemia, ↑LFTs
Palonosetron CI?
CI: hypersensitivity to drug, coadministration
with apomorphine ➡️profound hypotension and loss of consciousness
Palonosetron DI?
DI: serotonergic agents, SSRIs, SNRIs, anti‐
arrythmic agents, QT‐prolonging agents, agents
resulting in electrolyte abnormalities
Aprepitant/fosaprepitant
MOA?
selecƟve ⬆️‐affinity (‐) of human
substance P/neurokinin 1 (NK1) receptors; little
or no affinity for 5HT 3, D 2, and corticosteroid
receptors
Aprepitant/fosaprepitant
I?
adjunct to other antiemetics for prevention of
acute or delayed CINV, PONV
Aprepitant/fosaprepitant
CI?
hypersensitivity
concomitant Pimozideor
Cisapride use
Aprepitant/fosaprepitant
Kinetics?
A, D, M & E.
A=well absorbed orally bioavailability
60‐65%,
D=crosses BBB; 95% protein bound
M=hepatic CYP3A4 (major); CYP1A2, CYP2C19
(minor)Fosaprepitant (IV) rapidly converted
into Aprepitant in vivo
E=(IV admin): 57% urine;
45% faeces
Aprepitant/fosaprepitant DI?
CYP3A4 substrates, ketoconazole, rifampicin,
corticosteroids, benzodiazepines, warfarin, oral
contraceptives
N&V drugs to treat pregnancy?
*Sucrose/Phosphoric acid
*Dicyclomine/Doxylamine succinate/Pyridoxine